--- title: "P-21: Dosing & Vendor Prices | BodyHackGuide" url: https://www.bodyhackguide.co/compound/p-21 description: "P-21: dosing protocols, mechanism & side effects, 98 PubMed results. Compare 1 current vendor prices." lang: en --- Skip to content Compare notes on r/BodyHackGuide (https://reddit.com/r/bodyhackguide) Compare notes with other researchers. Join r/BodyHackGuide (https://reddit.com/r/bodyhackguide) # P-21 Nootropics (https://www.bodyhackguide.co/wiki#cat-nootropics)Preclinical Also known as: P21 P-21 (also written P021, or Peptide 021) is a synthetic peptidergic compound derived from the neurotrophic region of ciliary neurotrophic factor (CNTF), designed to activate neurogenic and BDNF-producing pathways in the adult brain without triggering the activation of the CNTF receptor that causes the undesirable side effects (cachexia, muscle wasting) that limited CNTF itself as a therapeutic. The compound emerged from a translational neuroscience research program at the New York State Institute for Basic Research in Developmental Disabilities, where Khalid Iqbal and colleagues characterized a region of CNTF that was responsible for the pro-neurogenic and cognitive effects without the adverse peripheral effects, then synthesized short peptides containing that functional motif ([Chohan et al., 2011]; [Blanchard et al., 2010]). Image: Disguised Alpha logo (https://disguisedalpha.com/wp-content/themes/assets/logos/disguised-logo-2x.png) Lowest price per mg $6.00/mg $59.99 for 10mg at Disguised Alpha Buy at Disguised Alpha: https://disguisedalpha.com/product/p21/?coupon=reddit MW: 578.67 g/mol (C27H42N6O8) 98 PubMed results (https://pubmed.ncbi.nlm.nih.gov/?term=P21%20peptide%20BDNF) Last reviewed: May 4, 2026 ## Overview ### At A Glance Mechanism P-21 is designed to engage a subset of CNTF's biological activity — specifically the neurogenic and BDNF-inducing effects — while avoiding the JAK/STAT3 activation on peripheral CNTF receptors that causes cachexia and muscle wasting when full-length CNTF is administered systemica… Dosing Once daily (some users divide into twice daily), typically dosed in the morning Dose Range 500-2000 mcg (0.5-2 mg) daily, most commonly 500-1000 mcg (community/self-experimentation range; no clinical validation) Potential Benefits Enhanced hippocampal neurogenesis (preclinical) Improved learning and memory (preclinical, rodent) Elevated BDNF and other neurotrophin expression Neuroprotective effects in Alzheimer's disease models (preclinical) Reduced tau hyperphosphorylation and soluble amyloid-beta in transgenic mice (preclinical) ### Overview P-21 (also written P021, or Peptide 021) is a synthetic peptidergic compound derived from the neurotrophic region of ciliary neurotrophic factor (CNTF), designed to activate neurogenic and BDNF-producing pathways in the adult brain without triggering the activation of the CNTF receptor that causes the undesirable side effects (cachexia, muscle wasting) that limited CNTF itself as a therapeutic. The compound emerged from a translational neuroscience research program at the New York State Institute for Basic Research in Developmental Disabilities, where Khalid Iqbal and colleagues characterized a region of CNTF that was responsible for the pro-neurogenic and cognitive effects without the adverse peripheral effects, then synthesized short peptides containing that functional motif ([Chohan et al., 2011]; [Blanchard et al., 2010]). P-21 is a small peptide (variable reported sequence across preparations) that has been tested in multiple rodent models including normal aged mice, Alzheimer's disease transgenic mice (3xTg-AD, APP/PS1), and models of age-related cognitive decline. The reported effects include increased hippocampal neurogenesis, elevated BDNF and other neurotrophin expression in the hippocampus and cortex, improved performance on hippocampus-dependent learning tasks (Morris water maze, novel object recognition), and reductions in pathological markers in AD models (amyloid plaque burden, tau hyperphosphorylation, synaptic deficits) ([Chohan et al., 2011]; [Kazim et al., 2014]; [Baazaoui & Iqbal, 2017]; [Bolognin et al., 2014]). These findings have attracted interest from both legitimate academic research (the compound has been evaluated as a potential AD therapeutic) and from biohacker communities seeking cognitive enhancement interventions. The practical reality in April 2026 is that P-21 has not progressed to human clinical trials, has no FDA approval, has no published pharmacokinetic data in humans, and is sold as a research peptide by vendors with variable quality control. Self-experimenters typically administer P-21 intranasally as a spray or drops, which bypasses the blood-brain barrier concerns that complicate peptide CNS delivery, though intranasal bioavailability and tissue distribution in humans are not characterized. Subcutaneous and oral administration are less common for P-21 because the intended target is the central nervous system and systemic administration provides poor brain penetration for most peptides. Enthusiasm for P-21 in biohacker circles is driven partly by its mechanistic story (pro-neurogenic, BDNF-activating, with preclinical data in AD models) and partly by marketing that sometimes conflates rodent efficacy data with implied human benefit. The honest framing is that P-21 is a mechanistically interesting research compound with good preclinical data in narrow model systems and no human validation. FDA-approved interventions for cognitive concerns — addressing cardiovascular risk factors, treating depression and anxiety, hearing and vision correction, social engagement, cognitive stimulation, exercise, adequate sleep, and specific interventions for diagnosed conditions (cholinesterase inhibitors, memantine for AD dementia; SSRIs for depression-related cognitive symptoms) — have evidence bases orders of magnitude stronger than any research peptide for cognitive or neurological outcomes. P-21 sits in the experimental category and should be framed accordingly rather than positioned as a legitimate cognitive enhancer or AD prevention strategy. This entry covers what P-21 actually does in the preclinical literature, how the CNTF-derived mechanism works, what the limitations of the evidence are, what the theoretical and practical concerns are for human use, and what a realistic approach looks like for anyone considering experimentation with the compound. ## Chemical Information IUPAC Name Not yet available CAS Number Not yet available Molecular Formula C104H167N29O30S Molecular Mass 578.67 g/mol Amino Acid Sequence Ac-DGGL(A)G-NH2 - an acetylated, C-terminally amidated synthetic peptide with an adamantylated glycine; derived from the active 4-residue region of ciliary neurotrophic factor (CNTF). The adamantane modification confers blood-brain-barrier permeability and resistance to exopeptidase degradation. It is the optimized derivative of the 11-mer parent 'Peptide 6' (residues from the active region of human CNTF). ## Dosing & Protocols ### Unlock the dosing protocols Enter your email to keep reading. It is free, and it opens these tabs on every compound page in this browser. - Dose, how often and how long - Beginner, intermediate and advanced protocols - Reconstitution and handling notes - Stacking notes You also get the free peptide cheat sheet by email. Unsubscribe anytime. Have an account? Sign in (https://www.bodyhackguide.co/auth) ## Research ### Unlock the research summary - A summary of the key research - Safety and side effects - A link to the PubMed results ## Interactions ### Interaction Matrix ### Contraindications P-21's CNS-targeted neurotrophic mechanism creates specific contraindications reflecting concerns about CNS disorders, cancer risk, reproductive safety, and drug interactions. Seizure disorders are a relative contraindication because BDNF and other neurotrophin elevation can lower seizure threshold in some contexts. Patients with epilepsy, febrile seizures, or significant risk factors for seizures should consult their neurologist before using P-21, and probably should not use the compound without specific clinical oversight. Active psychiatric conditions requiring medication are relative contraindications because neurotrophic signaling interacts with antidepressant, antipsychotic, and mood stabilizer mechanisms in complex ways. Patients on SSRIs, SNRIs, tricyclic antidepressants, MAOIs, atypical antidepressants, antipsychotics, or lithium should not use P-21 without their psychiatrist's involvement. This is particularly important for medications with narrow therapeutic windows or significant metabolic interactions. Active malignancy or recent cancer treatment (within 12 months) is a relative contraindication. Neurotrophic signaling and BDNF elevation have complex effects in tumors that depend on tumor type; some cancers express BDNF receptors and can be stimulated by BDNF, while others are unaffected. The theoretical concern is not strong, but in the absence of clinical data, patients with active cancer or under cancer surveillance should discuss P-21 with their oncologist before use. Pregnancy and breastfeeding are absolute contraindications. Neurotrophic signaling during embryonic development is precisely regulated, and exogenous BDNF elevation during gestation could disrupt normal brain development. Post-natal effects on infant brain development through lactation are uncharacterized. Anyone trying to conceive should avoid P-21. Children and adolescents should not use P-21 because the developing brain is highly sensitive to neurotrophic manipulation, and effects on normal maturation are uncharacterized. The compound has not been studied in developmental age groups, and use in this population is not appropriate. Stroke or traumatic brain injury in the acute or subacute phase is a relative contraindication because neurotrophic manipulation during active brain injury could have unpredictable effects on edema, inflammation, and tissue repair. Patients within 6 months of stroke or TBI should consult their neurologist before use. Chronic post-injury use may be acceptable but should involve physician input. Active infection including meningitis, encephalitis, or other CNS infections is an absolute contraindication for intranasal use because the infection could be worsened or disseminated. Avoid intranasal administration during any acute illness, particularly those involving respiratory or sinus symptoms. Known hypersensitivity to peptide products or to preservatives used in reconstitution (benzyl alcohol, parabens) is an absolute contraindication. History of allergic reactions to nasal sprays or other intranasal medications warrants caution. Chronic nasal or sinus conditions — chronic rhinosinusitis, allergic rhinitis with frequent symptoms, recurrent sinusitis, nasal polyps, prior nasal surgery — are relative contraindications for intranasal use because the nasal administration may exacerbate these conditions. Oral or subcutaneous routes may be considered but have different pharmacokinetic and bioavailability profiles that have not been validated for P-21. Bleeding disorders or anticoagulant therapy are not strict contraindications but warrant caution because nasal administration can cause minor bleeding in some users. Patients on warfarin, direct oral anticoagulants, or antiplatelet therapy should use intranasal P-21 conservatively and report any persistent nasal bleeding. Certain neurological conditions warrant specialist consultation: Alzheimer's disease and other dementias (where there is both theoretical rationale for neurotrophic intervention and significant unknowns about benefit-risk in the specific condition); Parkinson's disease (where neurotrophic manipulation could theoretically interact with dopaminergic function in complex ways); multiple sclerosis (where immunomodulation is the primary disease concern and neurotrophic effects are secondary); traumatic brain injury recovery (as above); and chronic pain conditions with CNS involvement. Medications with potential interactions include: antidepressants (all classes, as discussed above); anticonvulsants (seizure-lowering effects of BDNF); antipsychotics (neurotrophic pathway interactions); lithium (complex effects on neurotrophin signaling); stimulants used for ADHD (additive CNS activation); modafinil and armodafinil (uncertain CNS interactions); cholinesterase inhibitors and memantine (approved AD medications with theoretical overlap); corticosteroids (cortisol reduces BDNF, so corticosteroids may oppose P-21 effects); and any psychoactive medication with narrow therapeutic window or known CNS pharmacodynamic sensitivity. The final and most important contraindication is the absence of clinical oversight. Self-experimentation with a CNS-targeted research peptide without a physician or psychiatrist who knows about the use, can order appropriate assessments, and can evaluate adverse effects does not meet the minimum safety standard. The CNS is the organ system where adverse effects are most difficult to detect early and most consequential when they occur — subtle mood changes, cognitive shifts, or psychiatric symptoms may be missed by self-monitoring until they become significant. Clinical oversight provides the pattern-recognition capacity that self-assessment cannot. Finding a physician with expertise in neurotrophic research peptides is difficult but not impossible; establishing this clinical relationship before starting is worth the effort. Research Disclaimer This interaction data is compiled from published research and community reports. It may not be exhaustive. Always consult a healthcare professional before combining compounds. Best Price $59.99 Best $/mg $5.9990 Vendors 1 Listings 1 vial Form Sort | Vendor | Product | Form | Qty | Price | $/mg | Coupon | | | --- | --- | --- | --- | --- | --- | --- | --- | | Image: Disguised Alpha logo (https://disguisedalpha.com/wp-content/themes/assets/logos/disguised-logo-2x.png) Disguised Alpha (https://www.bodyhackguide.co/vendors/disguised-alpha) 50: https://www.bodyhackguide.co/vendor-trust-scorecard 🇺🇸 US 🇪🇺 EU 🇬🇧 UK | P21 10 mg | vial | 1 vial ● In Stock | $59.99 BEST | $6.00 | — | Buy: https://disguisedalpha.com/product/p21/?coupon=reddit | ### Sign in to leave a review Reviews on BodyHackGuide are tied to verified user accounts and moderated before publishing. Sign in (free, no spam) to share your experience with P-21. Current low $59.99 current listings 7-day low — not enough history yet 30-day low — not enough history yet 30-day change — not enough history yet Tracking since Sep 5, 2026 · 1 data point ### Vendors Selling P-21 #### Disguised Alpha 1 listing · from $59.99 https://www.bodyhackguide.co/vendors/disguised-alpha How we score these vendors Every supplier above is graded 0 to 100 on COA verification, payment transparency, shipping, reviews, and active listings. Methodology published, no pay-to-rank. View Scorecard (https://www.bodyhackguide.co/vendors/scorecard) ### Related Compounds View All (https://www.bodyhackguide.co/wiki) ### 9-Me-BC (9-Methyl-β-carboline) Nootropics Preclinical 9-Methyl--carboline (9-Me-BC) is a synthetic -carboline alkaloid that has drawn nootropic-community interest for a preclinical property that is genuinely unusual among -carbolines: in rodent and cell-culture studies it appears to stimulate the dopaminergic phenotype - raising tyrosine hydroxylase, the number of differentiated dopamine neurons and dopamine content - while also showing neuroprotective, neurorestorative and anti-inflammatory effects, plus in-vitro MAO-A/MAO-B inhibition [PMID:17913302, PMID:20374418, PMID:32285253]. t½ Not characterized in humans (no pharmacokinetic data). Community/anecdotal only: ~5-25 mg per day, oral. No validated or approved human dose exists. 6 PubMed View Profile https://www.bodyhackguide.co/compound/9-mbc ### Aniracetam Nootropics Approved (Italy) Aniracetam is a pyrrolidinone in the racetam family, developed by Hoffmann-La Roche under the code Ro 13-5057. t½ About half an hour for the parent drug in humans. Plasma elimination half-life was 0.47 to 0.49 hours after a single 400 mg oral dose in 20 healthy male volunteers (PMID: 19025058). Aniracetam is extensively metabolized to N-anisoyl-GABA and anisic acid; in six elderly hospitalized patients with cerebrovascular disease and reduced creatinine clearance, metabolite half-life was 4 to 7 times longer than in young volunteers (PMID: 9062694). Preclinical View Profile https://www.bodyhackguide.co/compound/aniracetam ### Bemethyl (bemitil) Nootropics Approved (Russia) Bemethyl, known in the Russian literature as bemitil and sold in the region under names including Metaprot, Bemactor and Antihot, is 2-ethylthiobenzimidazole, normally handled as the hydrobromide salt. t½ Not established in humans; in healthy volunteers given a single 250 mg oral dose of the Metaprot capsule form, peak serum ethylthiobenzimidazole averaged 0.91 microg/mL at about 1.06 h, and no terminal half-life was reported (PMID: 21870773) Preclinical View Profile https://www.bodyhackguide.co/compound/bemethyl ### Bromantane Nootropics Russia Approved Bromantane is an atypical psychostimulant and anxiolytic developed in the 1980s at the Zakusov Institute of Pharmacology of the Russian Academy of Medical Sciences, originally created as an adaptogen for Soviet military and elite athletic use and later approved in Russia for the treatment of neurasthenic and asthenic disorders under the trade name Ladasten. 34 PubMed View Profile https://www.bodyhackguide.co/compound/bromantane ### Cyclazodone Nootropics Preclinical Cyclazodone is the N-cyclopropyl derivative of pemoline, a 4-oxazolidinone stimulant. Preclinical View Profile https://www.bodyhackguide.co/compound/cyclazodone ### Dihexa Nootropics Preclinical Dihexa is a synthetic peptide analogue of the angiotensin IV metabolite LVV-hemorphin-7, developed at Washington State University. t½ Not characterized in humans. Dihexa was engineered for metabolic stability (resistant to plasma and enzymatic degradation) and blood-brain-barrier penetration; in preclinical work its central procognitive effects appear to outlast its plasma presence. 5 to 40 mg oral per day (anecdotal range; no established human dose) 1 PubMed View Profile https://www.bodyhackguide.co/compound/dihexa View Full Dosage Guide → Protocols, calculator & safety for P-21 https://www.bodyhackguide.co/guides/dosage/p-21 ### Lowest Price per mg Disguised Alpha $59.99($6.00/mg) 1 vendor · 1 listing ### Research Score 40 98 PubMed results ### Quality Indicators Data Completeness 100% Description Mechanism of Action Chemical Data Dosing Protocols Safety Profile PubMed Results Interactions Vendor Listings Research Volume 98 PubMed results Well-researched compound ### Quick Facts Molecular Weight 578.67 g/mol Trial Phase Preclinical 0 Research Disclaimer This information is for educational and research purposes only. Not intended as medical advice. Consult a healthcare professional before use. ## Frequently Asked Questions What does P-21 actually do in the brain? P-21 (P021) is a CNTF-derived neurotrophic/neurogenic peptide that increases neurogenesis in the hippocampal dentate gyrus, elevates BDNF and other neurotrophin expression, and improves performance on learning and memory tasks in rodent studies (Chohan et al., 2011 (https://pubmed.ncbi.nlm.nih.gov/19767127/); Blanchard et al., 2010 (https://pubmed.ncbi.nlm.nih.gov/20952820/)). It was derived from the most active 4-residue region of ciliary neurotrophic factor (CNTF) and engineered to preserve these central neurotrophic effects while avoiding the weight loss and cachexia caused by full-length CNTF. Has P-21 been tested in humans with Alzheimer's disease? No. As of 2026, no human clinical trials of P-21 have been conducted or published, despite disease-modifying effects in the 3xTg-AD transgenic mouse model (Kazim et al., 2014 (https://pubmed.ncbi.nlm.nih.gov/25046994/); Baazaoui & Iqbal, 2017 (https://pubmed.ncbi.nlm.nih.gov/28655344/)). The compound remains preclinical. Many neurotrophic strategies have failed in human AD trials despite promising mouse data, so caution about translation is warranted. How is P-21 administered, and does it need to be intranasal? Unlike most peptides, P-21 (P021) was specifically engineered for druggability: an adamantylated glycine on its C-terminus makes it blood-brain-barrier permeable and resistant to exopeptidase degradation. In the foundational rodent studies it was given orally (mixed into the diet) or by subcutaneous depot, and both routes reached the brain and produced effects (Kazim et al., 2014 (https://pubmed.ncbi.nlm.nih.gov/25046994/); Baazaoui & Iqbal, 2017 (https://pubmed.ncbi.nlm.nih.gov/28655344/)). Some self-experimenters use an intranasal route, but the common claim that P-21 must be given intranasally because peptides cannot cross the blood-brain barrier does not apply to this compound. No human pharmacokinetic data exist for any route. What dose of P-21 do people use? Self-report communities describe doses ranging from 500 mcg to 2000 mcg (0.5-2 mg) daily, with 500-1000 mcg being the most common range, dosed once daily (some divide into twice daily). These doses are extrapolated from rodent studies using allometric scaling and have no clinical validation in humans. How quickly should I expect to notice effects from P-21? Preclinical data suggest neurogenic effects develop over weeks, which is not compatible with expecting dramatic acute changes. Subjective effects (if present) typically emerge after 2-4 weeks of consistent dosing. Users who dose for a week and evaluate based on how they feel are unlikely to have meaningful data. A full 4-12 week cycle with before/after cognitive and mood assessment provides more informative results. Can P-21 help with depression or anxiety? The BDNF-promoting mechanism overlaps with the mechanism of antidepressants (which ultimately elevate BDNF), and users occasionally report mood improvements during P-21 cycles. However, there are no human studies of P-21 in depression or anxiety disorders, and combining P-21 with prescription antidepressants should involve psychiatrist input because the interaction is uncharacterized. For mood disorders, evidence-based treatments (psychotherapy, FDA-approved antidepressants, exercise) have far stronger evidence than research peptides. Is P-21 safe for long-term use? Long-term safety in humans is unknown. The compound has not been studied beyond the preclinical stage, and chronic manipulation of neurotrophic pathways over years could have effects that are not apparent in short-duration rodent studies. Cycling (4-12 weeks on, 4-8 weeks off) is the conservative approach that limits cumulative exposure and allows assessment of whether effects persist between cycles. Can P-21 be combined with other nootropics? Users commonly stack P-21 with conventional nootropic supplements (omega-3, magnesium L-threonate, choline sources, B vitamins) with generally good tolerability. Combination with other research peptides (like Semax (https://www.bodyhackguide.co/compound/semax) or Selank (https://www.bodyhackguide.co/compound/selank)) compounds unknowns and makes attribution impossible. Combination with prescription medications (antidepressants, stimulants) should involve physician consultation because of theoretical interactions. Does P-21 lower seizure threshold? BDNF elevation can lower seizure threshold in some contexts, and patients with epilepsy or seizure risk factors should consult their neurologist before using P-21. The clinical significance of this concern at typical research-peptide doses is not established, but caution is warranted for anyone with a history of seizures or conditions that predispose to them. Should I use P-21 if I have a neurodegenerative disease like Alzheimer's or Parkinson's? Patients with diagnosed neurodegenerative conditions should not use P-21 without explicit guidance from a neurologist familiar with the disease and with research peptide use. The theoretical rationale for neurotrophic intervention in these conditions is plausible, but no clinical validation exists, and self-experimentation with uncontrolled research peptides is not an appropriate substitute for evidence-based care. FDA-approved treatments (cholinesterase inhibitors, memantine, levodopa, dopamine agonists depending on the specific condition) should be the primary interventions, with P-21 or other research approaches considered only within clinical research contexts. ## Research Tools ### Peptide Calculator Reconstitution & syringe units https://www.bodyhackguide.co/tools/reconstitution ### Reconstitution Guide How to mix, step by step https://www.bodyhackguide.co/guides/how-to-reconstitute-peptides ### Nasal Spray Calc mL per actuation https://www.bodyhackguide.co/tools/intranasal ### Half-Life Visualizer Decay curves https://www.bodyhackguide.co/tools/halflife ## Related Compounds ### 9-Me-BC (9-Methyl-β-carboline) Nootropics Preclinical ### Aniracetam Nootropics Approved (Italy) ### Bemethyl (bemitil) Nootropics Approved (Russia) ### Bromantane Nootropics Russia Approved ### Cyclazodone Nootropics Preclinical ### Dihexa Nootropics Preclinical Free 2026 Peptide Cheat Sheet (PDF) 38 compounds and blends: vial sizes, BAC water volumes, dosing ranges and bloodwork markers. Download Free (https://www.bodyhackguide.co/guides/peptide-cheat-sheet-download) ### Need bloodwork before starting? Full hormone + metabolic panels from Anabolic Insights. Code CHONCH for first-order discount. Image: BodyHackGuide (https://www.bodyhackguide.co/assets/bodyhackguide-logo-DOzZNUyh.webp) ### BodyHackGuide Your biohacking research hub: compound pricing, brain health protocols, dosing tools, and vendor reviews. support@bodyhackguide.co Join our Discord: https://discord.gg/Mhq5UdRYBA r/BodyHackGuide on Reddit: https://reddit.com/r/BodyHackGuide #### Explore - Compare prices: https://www.bodyhackguide.co/compare - Vendors: https://www.bodyhackguide.co/vendors - Deals: https://www.bodyhackguide.co/deals - Coupons: https://www.bodyhackguide.co/coupons - Nootropics: https://www.bodyhackguide.co/nootropics - Brain health: https://www.bodyhackguide.co/brain-health - Blog: https://www.bodyhackguide.co/blog - Guides: https://www.bodyhackguide.co/guides #### Tools - Reconstitution: https://www.bodyhackguide.co/tools/reconstitution - Half-life visualizer: https://www.bodyhackguide.co/tools/halflife - COA reader: https://www.bodyhackguide.co/tools/coa - Cost calculator: https://www.bodyhackguide.co/tools/cost-calculator - Stack builder: https://www.bodyhackguide.co/stack-builder - All tools: https://www.bodyhackguide.co/tools #### Trust & vendors - Vendor directory: https://www.bodyhackguide.co/vendors - Trust scorecard: https://www.bodyhackguide.co/vendors/scorecard - Vendor trust badge: https://www.bodyhackguide.co/vendors/get-vetted - Scoring methodology: https://www.bodyhackguide.co/vendors/methodology - Peptide cheat sheet: https://www.bodyhackguide.co/guides/peptide-cheat-sheet-download #### Company - About: https://www.bodyhackguide.co/about - Affiliate disclosure: https://www.bodyhackguide.co/affiliate-disclosure - Editorial standards: https://www.bodyhackguide.co/editorial-standards - Creators: https://www.bodyhackguide.co/creators - Coaches: https://www.bodyhackguide.co/coaches - 1-on-1 coaching: https://www.bodyhackguide.co/coaching - Privacy: https://www.bodyhackguide.co/privacy - Terms: https://www.bodyhackguide.co/terms - Full site directory: https://www.bodyhackguide.co/site-directory **Affiliate Disclosure:** We rank every vendor on the same public, reproducible methodology (https://www.bodyhackguide.co/vendors/methodology), and we earn a commission from purchases made through some of our links at no extra cost to you. Full details in our affiliate disclosure (https://www.bodyhackguide.co/affiliate-disclosure). **Research Disclaimer:** All compounds listed are for laboratory and research purposes only. Not for human consumption. This site does not sell or ship any products. Always consult a qualified healthcare professional and comply with local regulations. © 2026 BodyHackGuide. All rights reserved. · Terms (https://www.bodyhackguide.co/terms) · Privacy (https://www.bodyhackguide.co/privacy) ## Structured data ```json [ { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://www.bodyhackguide.co/" }, { "@type": "ListItem", "position": 2, "name": "Compounds", "item": "https://www.bodyhackguide.co/compare" }, { "@type": "ListItem", "position": 3, "name": "P-21" } ] }, { "@context": "https://schema.org", "@type": "Product", "name": "P-21", "description": "P-21 (also written P021, or Peptide 021) is a synthetic peptidergic compound derived from the neurotrophic region of ciliary neurotrophic factor (CNTF), designed to activate neurogenic and BDNF-producing pathways in the adult brain without triggering the activation of the CNTF receptor that causes the undesirable side effects (cachexia, muscle wasting) that limited CNTF itself as a therapeutic. The compound emerged from a translational neuroscience research program at the New York State Institute for Basic Research in Developmental Disabilities, where Khalid Iqbal and colleagues characterized a region of CNTF that was responsible for the pro-neurogenic and cognitive effects without the adverse peripheral effects, then synthesized short peptides containing that functional motif ([Chohan et al., 2011]; [Blanchard et al., 2010]). P-21 is a small peptide (variable reported sequence across preparations) that has been tested in multiple rodent models including normal aged mice, Alzheimer's disease transgenic mice (3xTg-AD, APP/PS1), and models of age-related cognitive decline. The reported effects include increased hippocampal neurogenesis, elevated BDNF and other neurotrophin expression in the hippocampus and cortex, improved performance on hippocampus-dependent learning tasks (Morris water maze, novel object recognition), and reductions in pathological markers in AD models (amyloid plaque burden, tau hyperphosphorylation, synaptic deficits) ([Chohan et al., 2011]; [Kazim et al., 2014]; [Baazaoui & Iqbal, 2017]; [Bolognin et al., 2014]). These findings have attracted interest from both legitimate academic research (the compound has been evaluated as a potential AD therapeutic) and from biohacker communities seeking cognitive enhancement interventions. The practical reality in April 2026 is that P-21 has not progressed to human clinical trials, has no FDA approval, has no published pharmacokinetic data in humans, and is sold as a research peptide by vendors with variable quality control. Self-experimenters typically administer P-21 intranasally as a spray or drops, which bypasses the blood-brain barrier concerns that complicate peptide CNS delivery, though intranasal bioavailability and tissue distribution in humans are not characterized. Subcutaneous and oral administration are less common for P-21 because the intended target is the central nervous system and systemic administration provides poor brain penetration for most peptides. Enthusiasm for P-21 in biohacker circles is driven partly by its mechanistic story (pro-neurogenic, BDNF-activating, with preclinical data in AD models) and partly by marketing that sometimes conflates rodent efficacy data with implied human benefit. The honest framing is that P-21 is a mechanistically interesting research compound with good preclinical data in narrow model systems and no human validation. FDA-approved interventions for cognitive concerns — addressing cardiovascular risk factors, treating depression and anxiety, hearing and vision correction, social engagement, cognitive stimulation, exercise, adequate sleep, and specific interventions for diagnosed conditions (cholinesterase inhibitors, memantine for AD dementia; SSRIs for depression-related cognitive symptoms) — have evidence bases orders of magnitude stronger than any research peptide for cognitive or neurological outcomes. P-21 sits in the experimental category and should be framed accordingly rather than positioned as a legitimate cognitive enhancer or AD prevention strategy. This entry covers what P-21 actually does in the preclinical literature, how the CNTF-derived mechanism works, what the limitations of the evidence are, what the theoretical and practical concerns are for human use, and what a realistic approach looks like for anyone considering experimentation with the compound.", "url": "https://www.bodyhackguide.co/compound/p-21", "image": "https://www.bodyhackguide.co/og-image.png", "brand": { "@type": "Brand", "name": "Research Compound" }, "offers": { "@type": "AggregateOffer", "lowPrice": "59.99", "highPrice": "59.99", "priceCurrency": "USD", "offerCount": "1", "availability": "https://schema.org/InStock", "offers": [ { "@type": "Offer", "price": "59.99", "priceCurrency": "USD", "availability": "https://schema.org/InStock", "itemCondition": "https://schema.org/NewCondition", "url": "https://disguisedalpha.com/product/p21/?coupon=reddit", "seller": { "@type": "Organization", "name": "Disguised Alpha", "url": "https://disguisedalpha.com/?coupon=reddit" }, "name": "P-21 10mg vial" } ] } }, { "@context": "https://schema.org", "@type": "MedicalWebPage", "name": "P-21", "description": "P-21 (also written P021, or Peptide 021) is a synthetic peptidergic compound derived from the neurotrophic region of ciliary neurotrophic factor (CNTF), designed to activate neurogenic and BDNF-producing pathways in the adult brain without triggering the activation of the CNTF receptor that causes the undesirable side effects (cachexia, muscle wasting) that limited CNTF itself as a therapeutic. The compound emerged from a translational neuroscience research program at the New York State Institute for Basic Research in Developmental Disabilities, where Khalid Iqbal and colleagues characterized a region of CNTF that was responsible for the pro-neurogenic and cognitive effects without the adverse peripheral effects, then synthesized short peptides containing that functional motif ([Chohan et al., 2011]; [Blanchard et al., 2010]). P-21 is a small peptide (variable reported sequence across preparations) that has been tested in multiple rodent models including normal aged mice, Alzheimer's disease transgenic mice (3xTg-AD, APP/PS1), and models of age-related cognitive decline. The reported effects include increased hippocampal neurogenesis, elevated BDNF and other neurotrophin expression in the hippocampus and cortex, improved performance on hippocampus-dependent learning tasks (Morris water maze, novel object recognition), and reductions in pathological markers in AD models (amyloid plaque burden, tau hyperphosphorylation, synaptic deficits) ([Chohan et al., 2011]; [Kazim et al., 2014]; [Baazaoui & Iqbal, 2017]; [Bolognin et al., 2014]). These findings have attracted interest from both legitimate academic research (the compound has been evaluated as a potential AD therapeutic) and from biohacker communities seeking cognitive enhancement interventions. The practical reality in April 2026 is that P-21 has not progressed to human clinical trials, has no FDA approval, has no published pharmacokinetic data in humans, and is sold as a research peptide by vendors with variable quality control. Self-experimenters typically administer P-21 intranasally as a spray or drops, which bypasses the blood-brain barrier concerns that complicate peptide CNS delivery, though intranasal bioavailability and tissue distribution in humans are not characterized. Subcutaneous and oral administration are less common for P-21 because the intended target is the central nervous system and systemic administration provides poor brain penetration for most peptides. Enthusiasm for P-21 in biohacker circles is driven partly by its mechanistic story (pro-neurogenic, BDNF-activating, with preclinical data in AD models) and partly by marketing that sometimes conflates rodent efficacy data with implied human benefit. The honest framing is that P-21 is a mechanistically interesting research compound with good preclinical data in narrow model systems and no human validation. FDA-approved interventions for cognitive concerns — addressing cardiovascular risk factors, treating depression and anxiety, hearing and vision correction, social engagement, cognitive stimulation, exercise, adequate sleep, and specific interventions for diagnosed conditions (cholinesterase inhibitors, memantine for AD dementia; SSRIs for depression-related cognitive symptoms) — have evidence bases orders of magnitude stronger than any research peptide for cognitive or neurological outcomes. P-21 sits in the experimental category and should be framed accordingly rather than positioned as a legitimate cognitive enhancer or AD prevention strategy. This entry covers what P-21 actually does in the preclinical literature, how the CNTF-derived mechanism works, what the limitations of the evidence are, what the theoretical and practical concerns are for human use, and what a realistic approach looks like for anyone considering experimentation with the compound.", "lastReviewed": "2026-05-04T11:35:41.179+00:00", "url": "https://www.bodyhackguide.co/compound/p-21", "author": { "@type": "Person", "name": "BioChonch", "url": "https://www.bodyhackguide.co/about", "jobTitle": "Founder & Lead Researcher", "sameAs": [ "https://reddit.com/r/BodyHackGuide", "https://reddit.com/r/BrainHackGuide", "https://reddit.com/r/Biohackingher" ], "worksFor": { "@type": "Organization", "name": "BodyHackGuide", "url": "https://www.bodyhackguide.co" } }, "reviewedBy": { "@type": "Person", "name": "BioChonch", "url": "https://www.bodyhackguide.co/about", "jobTitle": "Founder & Lead Researcher", "sameAs": [ "https://reddit.com/r/BodyHackGuide", "https://reddit.com/r/BrainHackGuide", "https://reddit.com/r/Biohackingher" ], "worksFor": { "@type": "Organization", "name": "BodyHackGuide", "url": "https://www.bodyhackguide.co" } }, "publisher": { "@type": "Organization", "name": "BodyHackGuide", "url": "https://www.bodyhackguide.co" }, "mainContentOfPage": { "@type": "WebPageElement", "cssSelector": "main" }, "about": { "@type": "Drug", "name": "P-21", "alternateName": [ "P21" ], "description": "P-21 (also written P021, or Peptide 021) is a synthetic peptidergic compound derived from the neurotrophic region of ciliary neurotrophic factor (CNTF), designed to activate neurogenic and BDNF-producing pathways in the adult brain without triggering the activation of the CNTF receptor that causes the undesirable side effects (cachexia, muscle wasting) that limited CNTF itself as a therapeutic. The compound emerged from a translational neuroscience research program at the New York State Institute for Basic Research in Developmental Disabilities, where Khalid Iqbal and colleagues characterized a region of CNTF that was responsible for the pro-neurogenic and cognitive effects without the adverse peripheral effects, then synthesized short peptides containing that functional motif ([Chohan et al., 2011]; [Blanchard et al., 2010]). P-21 is a small peptide (variable reported sequence across preparations) that has been tested in multiple rodent models including normal aged mice, Alzheimer's disease transgenic mice (3xTg-AD, APP/PS1), and models of age-related cognitive decline. The reported effects include increased hippocampal neurogenesis, elevated BDNF and other neurotrophin expression in the hippocampus and cortex, improved performance on hippocampus-dependent learning tasks (Morris water maze, novel object recognition), and reductions in pathological markers in AD models (amyloid plaque burden, tau hyperphosphorylation, synaptic deficits) ([Chohan et al., 2011]; [Kazim et al., 2014]; [Baazaoui & Iqbal, 2017]; [Bolognin et al., 2014]). These findings have attracted interest from both legitimate academic research (the compound has been evaluated as a potential AD therapeutic) and from biohacker communities seeking cognitive enhancement interventions. The practical reality in April 2026 is that P-21 has not progressed to human clinical trials, has no FDA approval, has no published pharmacokinetic data in humans, and is sold as a research peptide by vendors with variable quality control. Self-experimenters typically administer P-21 intranasally as a spray or drops, which bypasses the blood-brain barrier concerns that complicate peptide CNS delivery, though intranasal bioavailability and tissue distribution in humans are not characterized. Subcutaneous and oral administration are less common for P-21 because the intended target is the central nervous system and systemic administration provides poor brain penetration for most peptides. Enthusiasm for P-21 in biohacker circles is driven partly by its mechanistic story (pro-neurogenic, BDNF-activating, with preclinical data in AD models) and partly by marketing that sometimes conflates rodent efficacy data with implied human benefit. The honest framing is that P-21 is a mechanistically interesting research compound with good preclinical data in narrow model systems and no human validation. FDA-approved interventions for cognitive concerns — addressing cardiovascular risk factors, treating depression and anxiety, hearing and vision correction, social engagement, cognitive stimulation, exercise, adequate sleep, and specific interventions for diagnosed conditions (cholinesterase inhibitors, memantine for AD dementia; SSRIs for depression-related cognitive symptoms) — have evidence bases orders of magnitude stronger than any research peptide for cognitive or neurological outcomes. P-21 sits in the experimental category and should be framed accordingly rather than positioned as a legitimate cognitive enhancer or AD prevention strategy. This entry covers what P-21 actually does in the preclinical literature, how the CNTF-derived mechanism works, what the limitations of the evidence are, what the theoretical and practical concerns are for human use, and what a realistic approach looks like for anyone considering experimentation with the compound.", "activeIngredient": "P-21", "mechanismOfAction": "P-21 is designed to engage a subset of CNTF's biological activity — specifically the neurogenic and BDNF-inducing effects — while avoiding the JAK/STAT3 activation on peripheral CNTF receptors that causes cachexia and muscle wasting when full-length CNTF is administered systemically. The parent molecule, CNTF (ciliary neurotrophic factor), signals through a tripartite receptor complex consisting of CNTF receptor alpha (CNTFR-alpha, a GPI-anchored ligand-binding subunit), gp130, and LIF receptor beta. Activation of this complex triggers JAK-STAT signaling, primarily STAT3 phosphorylation, and also activates MAPK/ERK and PI3K/Akt pathways. In the central nervous system, CNTF signaling supports neurogenesis in hippocampal and subventricular zones, stimulates expression of neurotrophic factors including BDNF and NGF, and promotes neuronal survival under stress conditions. In peripheral tissues, CNTF signaling through the same receptors causes weight loss and cachexia, and human trials of recombinant CNTF for ALS were limited by these adverse effects ([Chohan et al., 2011]; [Blanchard et al., 2010]). P-21 was designed to preserve the neurogenic and BDNF-inducing activity while reducing or eliminating the peripheral cachectic effect, by using a short peptide fragment that engages the relevant central signaling without the full signaling engagement of peripheral CNTF receptors. The exact mechanism by which P-21 produces its effects is less completely characterized than the original CNTF signaling pathway. P-21 appears to engage CNTF-pathway signaling in the CNS with different stoichiometry or different receptor subunit preferences than full-length CNTF, and the downstream effects on neurogenesis and BDNF expression are reproduced while peripheral signaling is reduced. The molecular details of this selectivity — which receptor subunits are engaged, whether the peptide acts as a full agonist, partial agonist, or biased agonist at these receptors — are not fully established, which is a limitation of the preclinical literature. Downstream of receptor engagement, P-21 administration in rodent studies produces: increased neurogenesis in the dentate gyrus of the hippocampus, measured by BrdU incorporation and doublecortin staining of newborn neurons; elevated BDNF expression in the hippocampus and cortex, measured by ELISA and western blot; increased expression of other neurotrophic factors (NGF, NT-3); activation of the CREB signaling pathway, which regulates gene programs involved in synaptic plasticity and memory; improved performance on learning and memory tasks, particularly those dependent on hippocampal function (Morris water maze, contextual fear conditioning, novel object recognition); in AD model mice, reductions in amyloid-beta plaque burden, attenuation of tau hyperphosphorylation, preservation of synaptic markers (synaptophysin, PSD-95), and improved cognitive performance ([Chohan et al., 2011]; [Kazim et al., 2014]; [Baazaoui & Iqbal, 2017]). The mechanism of action on amyloid and tau pathology in AD models is presumed to be indirect — P-21 does not directly modulate amyloid production, clearance, or aggregation kinetics, and it does not directly inhibit tau kinases. Instead, the proposed mechanism is that P-21-induced neurogenesis and BDNF upregulation creates a more neuroprotective microenvironment in which new neurons replace or compensate for dysfunction in existing circuits, and elevated BDNF supports synaptic function in surviving neurons. These effects could plausibly slow the progression of synaptic and cognitive decline even in the continued presence of amyloid and tau pathology. Whether this mechanism translates to human AD — where the pathology is more advanced and chronic than in rodent models, and where the aged brain has reduced baseline neurogenic capacity — is the key translational question that has not been answered. Intranasal administration (the most common route in self-experimentation) is relevant to the mechanism because intranasal peptides can reach the brain through several proposed routes: direct transport along olfactory nerve fibers from the nasal epithelium to the olfactory bulb and from there to other brain regions; transport along trigeminal nerve fibers to the brainstem and nearby structures; and systemic absorption through the rich nasal vasculature followed by some degree of blood-brain barrier penetration. The relative contribution of these routes varies by peptide and is not well characterized for P-21 specifically. Intranasal administration typically produces much higher CNS:plasma ratios than systemic administration, which is the rationale for the nasal route with CNS-targeted peptides.", "dosageForm": "vial", "legalStatus": "Not approved for human use (research chemical)", "warning": "For research purposes only. Not for human consumption." } }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "What does P-21 actually do in the brain?", "acceptedAnswer": { "@type": "Answer", "text": "P-21 (P021) is a CNTF-derived neurotrophic/neurogenic peptide that increases neurogenesis in the hippocampal dentate gyrus, elevates BDNF and other neurotrophin expression, and improves performance on learning and memory tasks in rodent studies (Chohan et al., 2011; Blanchard et al., 2010). It was derived from the most active 4-residue region of ciliary neurotrophic factor (CNTF) and engineered to preserve these central neurotrophic effects while avoiding the weight loss and cachexia caused by full-length CNTF." } }, { "@type": "Question", "name": "Has P-21 been tested in humans with Alzheimer's disease?", "acceptedAnswer": { "@type": "Answer", "text": "No. As of 2026, no human clinical trials of P-21 have been conducted or published, despite disease-modifying effects in the 3xTg-AD transgenic mouse model (Kazim et al., 2014; Baazaoui & Iqbal, 2017). The compound remains preclinical. Many neurotrophic strategies have failed in human AD trials despite promising mouse data, so caution about translation is warranted." } }, { "@type": "Question", "name": "How is P-21 administered, and does it need to be intranasal?", "acceptedAnswer": { "@type": "Answer", "text": "Unlike most peptides, P-21 (P021) was specifically engineered for druggability: an adamantylated glycine on its C-terminus makes it blood-brain-barrier permeable and resistant to exopeptidase degradation. In the foundational rodent studies it was given orally (mixed into the diet) or by subcutaneous depot, and both routes reached the brain and produced effects (Kazim et al., 2014; Baazaoui & Iqbal, 2017). Some self-experimenters use an intranasal route, but the common claim that P-21 must be given intranasally because peptides cannot cross the blood-brain barrier does not apply to this compound. No human pharmacokinetic data exist for any route." } }, { "@type": "Question", "name": "What dose of P-21 do people use?", "acceptedAnswer": { "@type": "Answer", "text": "Self-report communities describe doses ranging from 500 mcg to 2000 mcg (0.5-2 mg) daily, with 500-1000 mcg being the most common range, dosed once daily (some divide into twice daily). These doses are extrapolated from rodent studies using allometric scaling and have no clinical validation in humans." } }, { "@type": "Question", "name": "How quickly should I expect to notice effects from P-21?", "acceptedAnswer": { "@type": "Answer", "text": "Preclinical data suggest neurogenic effects develop over weeks, which is not compatible with expecting dramatic acute changes. Subjective effects (if present) typically emerge after 2-4 weeks of consistent dosing. Users who dose for a week and evaluate based on how they feel are unlikely to have meaningful data. A full 4-12 week cycle with before/after cognitive and mood assessment provides more informative results." } }, { "@type": "Question", "name": "Can P-21 help with depression or anxiety?", "acceptedAnswer": { "@type": "Answer", "text": "The BDNF-promoting mechanism overlaps with the mechanism of antidepressants (which ultimately elevate BDNF), and users occasionally report mood improvements during P-21 cycles. However, there are no human studies of P-21 in depression or anxiety disorders, and combining P-21 with prescription antidepressants should involve psychiatrist input because the interaction is uncharacterized. For mood disorders, evidence-based treatments (psychotherapy, FDA-approved antidepressants, exercise) have far stronger evidence than research peptides." } }, { "@type": "Question", "name": "Is P-21 safe for long-term use?", "acceptedAnswer": { "@type": "Answer", "text": "Long-term safety in humans is unknown. The compound has not been studied beyond the preclinical stage, and chronic manipulation of neurotrophic pathways over years could have effects that are not apparent in short-duration rodent studies. Cycling (4-12 weeks on, 4-8 weeks off) is the conservative approach that limits cumulative exposure and allows assessment of whether effects persist between cycles." } }, { "@type": "Question", "name": "Can P-21 be combined with other nootropics?", "acceptedAnswer": { "@type": "Answer", "text": "Users commonly stack P-21 with conventional nootropic supplements (omega-3, magnesium L-threonate, choline sources, B vitamins) with generally good tolerability. Combination with other research peptides (like Semax or Selank) compounds unknowns and makes attribution impossible. Combination with prescription medications (antidepressants, stimulants) should involve physician consultation because of theoretical interactions." } }, { "@type": "Question", "name": "Does P-21 lower seizure threshold?", "acceptedAnswer": { "@type": "Answer", "text": "BDNF elevation can lower seizure threshold in some contexts, and patients with epilepsy or seizure risk factors should consult their neurologist before using P-21. The clinical significance of this concern at typical research-peptide doses is not established, but caution is warranted for anyone with a history of seizures or conditions that predispose to them." } }, { "@type": "Question", "name": "Should I use P-21 if I have a neurodegenerative disease like Alzheimer's or Parkinson's?", "acceptedAnswer": { "@type": "Answer", "text": "Patients with diagnosed neurodegenerative conditions should not use P-21 without explicit guidance from a neurologist familiar with the disease and with research peptide use. The theoretical rationale for neurotrophic intervention in these conditions is plausible, but no clinical validation exists, and self-experimentation with uncontrolled research peptides is not an appropriate substitute for evidence-based care. FDA-approved treatments (cholinesterase inhibitors, memantine, levodopa, dopamine agonists depending on the specific condition) should be the primary interventions, with P-21 or other research approaches considered only within clinical research contexts." } } ] }, { "@context": "https://schema.org", "@type": "Organization", "@id": "https://www.bodyhackguide.co#organization", "name": "BodyHackGuide", "alternateName": "BHG", "url": "https://www.bodyhackguide.co", "logo": { "@type": "ImageObject", "url": "https://www.bodyhackguide.co/logo.png", "width": 512, "height": 512 }, "description": "Evidence-based research reference for peptides and nootropics. 124+ compound profiles, interactive dosing calculators, vendor price comparisons, and trust-scored vendor reviews scored on a public, reproducible methodology applied to every vendor. We earn a commission on purchases through some of our links.", "foundingDate": "2024", "founder": { "@id": "https://www.bodyhackguide.co/about#person" }, "sameAs": [ "https://reddit.com/r/BodyHackGuide", "https://reddit.com/r/BrainHackGuide", "https://reddit.com/r/Biohackingher", "https://discord.gg/Mhq5UdRYBA" ], "knowsAbout": [ "Peptide research", "Nootropic research", "Biohacking", "Compound dosing", "Vendor transparency" ], "publishingPrinciples": "https://www.bodyhackguide.co/editorial-standards", "ethicsPolicy": "https://www.bodyhackguide.co/editorial-standards", "diversityPolicy": "https://www.bodyhackguide.co/editorial-standards" } ] ```