--- title: "Semax vs Selank: Nootropic Peptide Comparison" url: https://www.bodyhackguide.co/blog/semax-vs-selank description: "Semax vs Selank compared: mechanisms, real (mostly Russian) evidence, intranasal dosing, who each suits, and how people stack them. Honest, cited" lang: en --- Skip to content Compare notes with other researchers. Join r/BodyHackGuide (https://reddit.com/r/bodyhackguide) Image: Semax vs Selank: which Russian nasal peptide actually fits you? (https://www.bodyhackguide.co/og-image.png) nootropics 11 min read Jun 30, 2026 Updated Sep 11, 2026 Fact-checked (https://www.bodyhackguide.co/editorial-standards) # Semax vs Selank: which Russian nasal peptide actually fits you? Semax is an ACTH(4-10) analog that pushes BDNF and trkB for focus, cognition, and recovery; Selank is a tuftsin analog that blocks enkephalinase for calm without sedation. Both are intranasal, both lean on small Russian trials and rodent data, and neither is FDA-approved. Pick Semax for drive, Selank for anxiety. B BioChonch Founder, BodyHackGuide Key Takeaway Key Takeaway Semax and Selank are both Russian heptapeptides taken intranasally, but they do different jobs. Semax (an ACTH(4-10) analog) raises BDNF and trkB in the hippocampus and leans toward focus, cognition, and recovery. Selank (a tuftsin/TP-7 analog) blocks enkephalin-degrading enzymes and leans toward calm and anxiety relief without sedation. The catch: almost all the human evidence is small, Russian, and unreplicated in the West, and the sub-clinical "nootropic" doses people actually use have no controlled trials behind them. If you spend any time in nootropics forums, these two peptides come up constantly, usually together, and usually with a lot of confident claims that the underlying research does not support. So let me lay it out straight. Both are short peptides. Both are sprayed up the nose. Both came out of the same cluster of Moscow research institutes. And both have a "focus vs calm" reputation that is roughly accurate but messier than the marketing implies. Here is the head-to-head before we get into the why. Semax structure Met-Glu-His-Phe-Pro-Gly-Pro ACTH(4-10) analog Selank structure Thr-Lys-Pro-Arg-Pro-Gly-Pro tuftsin / TP-7 analog Semax lean Focus / cognition BDNF + trkB up Selank lean Calm / anxiety enkephalinase blocked Largest human trial 110 (Semax stroke) Selank RCT size 62 (vs benzo) ## what Semax actually is Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro. It's built from the ACTH(4-7) fragment with a Pro-Gly-Pro tail bolted on the end. That tail matters: it slows enzymatic breakdown, which is why a fragile peptide survives long enough to do anything. Despite the ACTH lineage, Semax is non-corticotropic. It does not jack up cortisol. The adrenocorticotropic part of the parent molecule was, in effect, engineered out, leaving the neurotropic behavior behind. The core mechanism, at least in rodents, is the BDNF/trkB system. BDNF is brain-derived neurotrophic factor, the growth factor most tied to learning, plasticity, and neuron survival; trkB is its receptor. According to PubMed, a single intranasal dose of Semax at 50 mcg/kg in rats produced roughly a 1.4-fold rise in hippocampal BDNF protein, about a 1.6-fold increase in trkB phosphorylation, and 3-fold and 2-fold jumps in BDNF and trkB mRNA, with the animals showing better conditioned avoidance learning PMID: 16996037 (https://pubmed.ncbi.nlm.nih.gov/16996037) (DOI (https://doi.org/10.1016/j.brainres.2006.07.108)). A related study found rapid, region-specific bumps in BDNF and NGF gene expression within an hour of the same dose PMID: 17353092 (https://pubmed.ncbi.nlm.nih.gov/17353092) (DOI (https://doi.org/10.1016/j.neulet.2007.02.042)). There's also binding evidence that this isn't some vague nonspecific effect. Semax binds specific, reversible, calcium-dependent sites in rat basal forebrain with a KD around 2.4 nM, and intranasal dosing raised BDNF protein within three hours PMID: 16635254 (https://pubmed.ncbi.nlm.nih.gov/16635254) (DOI (https://doi.org/10.1111/j.1471-4159.2006.03658.x)). A KD in the low nanomolar range is the kind of affinity you'd expect from a real receptor interaction, not background noise. For humans, the meaningful data is a stroke trial. In 110 ischemic-stroke patients, the standard Russian regimen of 6000 mcg/day (two 10-day courses with a 20-day gap) raised plasma BDNF and sped up motor recovery and Barthel index improvement PMID: 29798983 (https://pubmed.ncbi.nlm.nih.gov/29798983) (DOI (https://doi.org/10.17116/jnevro20181183261-68)). Semax is a registered drug in Russia for stroke and cognitive indications. It is not approved by the FDA or any Western regulator. One nuance worth flagging: Semax is not purely a stimulant-style focus drug. Chronic dosing in rats (0.05 mg/kg daily for 10-14 days) produced anxiolytic and antidepressant-like effects, attributed to serotonergic activation plus higher hippocampal BDNF PMID: 17850024 (https://pubmed.ncbi.nlm.nih.gov/17850024). A 2024 study in a chronic unpredictable stress model showed Semax (60 nmol/kg/day) blunted anhedonia, adrenal hypertrophy, and the stress-driven drop in BDNF PMID: 39442746 (https://pubmed.ncbi.nlm.nih.gov/39442746) (DOI (https://doi.org/10.1016/j.ejphar.2024.177068)). So the "Semax = focus only" story is incomplete. You can dig into the full mechanism breakdown on the Semax compound page (https://www.bodyhackguide.co/compound/semax). ## what Selank actually is Selank is also a heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro. It's a synthetic analog of tuftsin, an endogenous immunopeptide, and goes by the lab name TP-7. Same Pro-Gly-Pro stabilizing tail as Semax, different head. Its leading mechanism is enkephalinase inhibition. Enkephalins are your endogenous opioid peptides, and they get chewed up quickly by enkephalin-degrading enzymes. Selank slows that breakdown, so your own enkephalins stick around longer. In human plasma it inhibits enkephalin hydrolysis with an IC50 around 15 uM, more potently than the reference inhibitors bacitracin and puromycin, and patients with generalized anxiety showed shortened enkephalin half-life that Selank helped normalize PMID: 11550013 (https://pubmed.ncbi.nlm.nih.gov/11550013) (DOI (https://doi.org/10.1023/a:1017979514274)). The mouse data backs this up: 100 mcg/kg produced an anxiolytic effect in the open-field test and lengthened leu-enkephalin half-life in anxiety-prone BALB/c mice PMID: 12432865 (https://pubmed.ncbi.nlm.nih.gov/12432865) (DOI (https://doi.org/10.1023/a:1015582302311)). The standout human study is a 62-patient comparative RCT against medazepam, a benzodiazepine, in generalized anxiety disorder and neurasthenia. Selank matched the benzo's anxiolytic effect, added anti-asthenic and mild psychostimulant effects, and normalized leu-enkephalin half-life PMID: 18454096 (https://pubmed.ncbi.nlm.nih.gov/18454096). Matching a benzo without the sedation, tolerance, and dependence is the whole pitch for Selank. The trial is small, single-center, and Russian, so hold it loosely, but it exists and it's a real RCT. Selank's anxiolytic profile is durable, not just acute. The tuftsin analog TP-7 (which is Selank) at 0.3 mg/kg cut anxiety-phobic behavior in rats from day 2 and held over four weeks, with no effect on body weight PMID: 16963804 (https://pubmed.ncbi.nlm.nih.gov/16963804). And like Semax, it touches cognition: Selank at 0.3 mg/kg/day for a week prevented ethanol-withdrawal memory deficits while normalizing BDNF in the hippocampus and frontal cortex PMID: 31625062 (https://pubmed.ncbi.nlm.nih.gov/31625062) (DOI (https://doi.org/10.1007/s10517-019-04588-9)). It also has documented immunomodulatory and antiviral activity, altering chemokine and cytokine gene expression in spleen PMID: 21786679 (https://pubmed.ncbi.nlm.nih.gov/21786679). More detail lives on the Selank compound page (https://www.bodyhackguide.co/compound/selank). ## the mechanisms side by side The clean story is: Semax works through neurotrophins (BDNF/trkB), Selank works through the endogenous opioid system (enkephalinase inhibition). That heuristic holds up. But notice the overlap. Semax shows anxiolytic and antidepressant effects in rodents. Selank normalizes BDNF and helps cognition in a withdrawal model. The two are not as cleanly separated as "stimulant vs calmer" suggests, because both ultimately nudge plasticity and mood-related circuitry, just from different entry points. Here's where it gets murky, and I'd rather say it plainly: the bulk of mechanistic data is rodent, and the human data is two small Russian trials plus a registry approval. There are no large, blinded, placebo-controlled Western trials. There is no independent replication. Be skeptical of anyone who tells you either peptide is "proven" for memory, anxiety, or anything else outside the Russian regulatory context. ## dosing, route, and onset Both peptides get destroyed in the gut, so the standard route is intranasal. That's why you see them sold as atomized nasal sprays rather than capsules. If you're new to intranasal delivery, the intranasal dosing tool (https://www.bodyhackguide.co/tools/intranasal) covers technique, and if you're working with lyophilized powder, the reconstitution calculator (https://www.bodyhackguide.co/tools/reconstitution) handles the math. On dose, I have to draw a hard line between what's in the literature and what people actually do: Sub-clinical doses are anecdotal, not validated The popular "nootropic" doses below come from community practice, not controlled trials. The only clinically tested Semax dose I can cite is the 6000 mcg/day stroke regimen PMID: 29798983 (https://pubmed.ncbi.nlm.nih.gov/29798983). No one has run a dose-finding study for the small daily doses biohackers use. Treat the numbers as folklore, not medicine. In practice, intranasal Semax is commonly dosed around 300-600 mcg/day, often split, with subjective focus or alertness reported within roughly 15-60 minutes. Selank runs a similar intranasal range, around 250-900 mcg/day, with a calming onset people describe within 30-60 minutes. Again: these onset times and doses are not from controlled Western trials. They're what the community reports. Typical Semax (anecdotal) 300-600 mcg/day split dosing common Typical Selank (anecdotal) 250-900 mcg/day Clinical Semax (stroke) 6000 mcg/day PMID:29798983 Route Intranasal GI-degraded peptides ## who each one suits If your bottleneck is drive, mental stamina, recall, or you're chasing neuroprotection and recovery, Semax is the more logical pick. The BDNF/trkB mechanism and the stroke data both point that direction. If your bottleneck is anxiety, a racing mind, or stress that wrecks your focus, Selank is the more logical pick. It calms without the sedation, dependence, or next-day fog of a benzodiazepine, which is exactly what the GAD trial measured. The popular stack Plenty of people run Semax in the morning for drive and Selank later or as-needed for calm. It's a reasonable pairing on paper, the mechanisms don't obviously conflict. But there are zero controlled studies on the combination. Anyone presenting "Semax + Selank stack" as evidence-based is overselling it. It's a popular anecdotal practice, full stop. ## safety and the honest caveats In the mostly Russian literature, both peptides show clean short-term tolerability, no benzodiazepine-style dependence, no sedation, no documented withdrawal. That's reassuring as far as it goes. It does not go very far. Long-term human safety data outside Russia is essentially nonexistent. Both are research-use-only. They are not approved for human consumption in the US, EU, UK, or most other Western jurisdictions. If you have a psychiatric condition or take psychiatric medication, talk to a clinician first, especially with Selank, since its enkephalin mechanism touches the opioid system and the interaction profile with serotonergic or opioid drugs is unstudied. Avoid both if pregnant or nursing. Interactions broadly are unknown. ## where to get research-grade material Quality matters more here than with most supplements, because peptide purity and accurate labeling are not guaranteed in a gray market. For research-use-only Semax and Selank, BHG Labs (https://www.bodyhackguide.co/vendors/bhg-labs) sells both as atomized nasal products that are lot-numbered and linked to third-party certificates of analysis (COA), which is the bar you want before anything goes near your body. - Semax (atomized nasal, ~$89.99): BHG Labs Semax (https://bhglabs.co/product/semax/?ref=zmgqyxku&coupon=BHG20) - Selank (atomized nasal, ~$89.99): BHG Labs Selank (https://bhglabs.co/product/selank/?ref=zmgqyxku&coupon=BHG20) Use code **BHG20** for 20% off. Compare it first See how BHG Labs stacks up against other suppliers on the vendor scorecard (https://www.bodyhackguide.co/vendors/scorecard). ## further reading - Semax compound profile: https://www.bodyhackguide.co/compound/semax - Selank compound profile: https://www.bodyhackguide.co/compound/selank - Noopept, the racetam-adjacent nootropic: https://www.bodyhackguide.co/compound/noopept - Tesofensine for appetite and focus: https://www.bodyhackguide.co/compound/tesofensine - Intranasal dosing tool: https://www.bodyhackguide.co/tools/intranasal - Vendor scorecard: https://www.bodyhackguide.co/vendors/scorecard Research citations retrieved from PubMed. Where available, DOI links are included inline next to each citation. ## Frequently asked Semax is the better choice for focus and cognition. Its main mechanism is raising BDNF and activating the trkB receptor in the hippocampus, the system tied to learning and mental performance, and the human evidence (a 110-patient stroke trial) showed cognitive and motor recovery benefits. Selank can sharpen focus indirectly by removing anxiety, but it's primarily an anxiolytic. Share this article: 𝕏 / Twitter (https://twitter.com/intent/tweet?text=Semax%20vs%20Selank%3A%20which%20Russian%20nasal%20peptide%20actually%20fits%20you%3F&url=https%3A%2F%2Fwww.bodyhackguide.co%2Fblog%2Fsemax-vs-selank) B BioChonch (https://www.bodyhackguide.co/about)Founder & Lead Researcher Founder, BodyHackGuide Join r/BodyHackGuide on Reddit: https://reddit.com/r/bodyhackguide Join Discord: https://discord.gg/Mhq5UdRYBA | About the author: https://www.bodyhackguide.co/about ## Discussion Sign in to join the discussion No comments yet. 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All rights reserved. · Terms (https://www.bodyhackguide.co/terms) · Privacy (https://www.bodyhackguide.co/privacy) Shop BHG Labs · 20% off with BHG20: https://bhglabs.co/shop/?ref=zmgqyxku&coupon=BHG20 ## 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": "Blog", "item": "https://www.bodyhackguide.co/blog" }, { "@type": "ListItem", "position": 3, "name": "Semax vs Selank: which Russian nasal peptide actually fits you?" } ] }, { "@context": "https://schema.org", "@type": "BlogPosting", "headline": "Semax vs Selank: which Russian nasal peptide actually fits you?", "description": "Semax is an ACTH(4-10) analog that pushes BDNF and trkB for focus, cognition, and recovery; Selank is a tuftsin analog that blocks enkephalinase for calm without sedation. 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Its main mechanism is raising BDNF and activating the trkB receptor in the hippocampus, the system tied to learning and mental performance, and the human evidence (a 110-patient stroke trial) showed cognitive and motor recovery benefits. Selank can sharpen focus indirectly by removing anxiety, but it's primarily an anxiolytic." } }, { "@type": "Question", "name": "Can you take Semax and Selank together?", "acceptedAnswer": { "@type": "Answer", "text": "People commonly stack them, often Semax in the morning for drive and Selank later for calm, and the mechanisms don't obviously conflict. But there are no controlled studies on the combination, so it's an anecdotal practice rather than an evidence-based protocol. If you try it, start one peptide at a time so you can tell what's doing what." } }, { "@type": "Question", "name": "Are Semax and Selank FDA approved?", "acceptedAnswer": { "@type": "Answer", "text": "No. Neither is approved by the FDA or any Western regulator. Both are registered drugs in Russia (Semax for stroke and cognitive indications), but everywhere else they're sold strictly as research-use-only materials. They are not approved for human consumption in the US, EU, or UK." } }, { "@type": "Question", "name": "How are Semax and Selank taken?", "acceptedAnswer": { "@type": "Answer", "text": "Both are taken intranasally, usually as an atomized nasal spray. They're peptides that get broken down in the digestive tract, so swallowing them doesn't work. The Pro-Gly-Pro tail on both molecules improves their stability against enzymes compared to the parent peptides." } }, { "@type": "Question", "name": "Does Selank cause dependence like a benzodiazepine?", "acceptedAnswer": { "@type": "Answer", "text": "In the available literature, no. A 62-patient trial compared Selank to the benzodiazepine medazepam and found similar anxiety relief without the sedation, and no benzodiazepine-style dependence or withdrawal has been reported. That said, long-term human safety data outside Russia is essentially nonexistent, so this is \"no reported dependence,\" not a guarantee." } }, { "@type": "Question", "name": "How fast do Semax and Selank work?", "acceptedAnswer": { "@type": "Answer", "text": "Community reports put Semax's focus or alertness onset around 15-60 minutes after an intranasal dose, and Selank's calming onset around 30-60 minutes. These timings come from anecdotal user experience, not controlled trials, so treat them as rough expectations rather than established pharmacology." } }, { "@type": "Question", "name": "Is the evidence for Semax and Selank strong?", "acceptedAnswer": { "@type": "Answer", "text": "Honestly, it's thin. Most mechanistic data is from rodents, and the human evidence is two small, single-center Russian trials with no independent Western replication and no large placebo-controlled studies. The mechanisms are plausible and the early data is encouraging, but anyone calling these peptides \"proven\" is overstating the case." } } ] }, { "@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. 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