Semax vs PE-22-28
Side-by-side comparison of Semax and PE-22-28: mechanism, half-life, dose range, safety profile, and vendor pricing.
Price snapshot
Semax
PE-22-28
Semax
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro, MEHFPGP, 813 Da molecular weight) developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the 1980s. The compound is derived…
Lowest listed price: $32.90 across 5 listings
Full Semax profilePE-22-28
PE-22-28 is a synthetic seven-amino-acid peptide (sequence PAGASRLLLLTGEIDLP derivative, commonly truncated to PE-22-28 as shorthand for "position 22-28" within the parent humanin-family sequence) that was designed as an…
Lowest listed price: $49.99 across 1 listing
Full PE-22-28 profileSide-by-side comparison
| Attribute | Semax | PE-22-28 |
|---|---|---|
| Category | Nootropics | Nootropics |
| Research Stage | Approved in Russia; registered as a prescription intranasal solution | Preclinical |
| Mechanism of Action | Primary Mechanism: Multi-Pathway Neurotrophic Activation Semax produces its effects through coordinated activation of multiple neurotrophic, neurotransmitter, and neuroprotective pathways. Unlike conventional nootropics that target a single system (modafinil… | PE-22-28 is a synthetic 7-amino-acid peptide (sequence GVSWGLR) and a shortened analog of spadin. Its proposed mechanism is inhibition of the TREK-1 (TWIK-related K+) channel, a two-pore-domain potassium channel (K2P2.1 / KCNK2) implicated in mood regulation.… |
| Half-Life | ~2-3 minutes plasma half-life (functional neurological effects persist 12-24 hours due to BDNF/NGF gene expression changes) | Not characterized in humans. As a small 7-amino-acid peptide a short plasma half-life is expected; in mice the parent peptide spadin lost antidepressant activity by about 7 hours after a single dose, while modified analogs (e.g., G/A-PE 22-28) extended the behavioral effect to roughly 21-23 hours [PMID:28955242]. |
| Typical Dose Range | 100-900 mcg intranasal daily (0.1% solution: 2-3 drops per nostril 2-3x daily); 1% solution used for acute stroke in Russian clinical protocols | 250-2000 mcg subcutaneous per dose (empirical research-chemical community range; no clinically validated human dose exists; effective preclinical rodent doses were far lower, ~3 mcg/kg). |
| Dosing Frequency | Intranasal 1–3 times daily | Once daily or every other day (research-chemical community protocols; no validated clinical dosing schedule). |
| Administration | Intranasal | — |
| Side Effects | Overall Safety Profile Semax has an excellent safety profile across 20+ years of Russian clinical use. In acute stroke trials, cognitive studies, and pediatric applications, Semax has demonstrated consistent tolerability with minimal adverse event burden. This… | No human side-effect data exist for PE-22-28 because it has never been tested in people. What can be said comes from rodent studies of PE-22-28, spadin and their analogs, plus general considerations for injected research peptides. In the preclinical work, the… |
| Molecular Weight | 813.9 Da | 773.9 g/mol |
| Common Vial Sizes | 5mg, 10mg | — |
Price History
5 data points- OF
- Half Nattys
- Ion Peptide
- BHG Labs
Price History
2 data pointsSemax: potential benefits
- Rapid BDNF/TrkB upregulation in the hippocampus, supporting synaptic plasticity and learning (PMID: 16996037)
- Neuroprotective, immunomodulatory gene-expression changes in focal cerebral ischemia (middle cerebral artery occlusion) models (PMID: 28255762)
- Cognitive enhancement including improved attention, working memory, and processing speed
- Dopaminergic modulation that may support motivation and executive function (preclinical data)
- Stroke recovery facilitation - accelerated functional recovery and improved Barthel Index in ischemic stroke patients; approved in Russia for ischemic stroke (PMID: 29798983)
- Anxiolytic and anti-asthenic effects reported in Russian clinical use, attributed to neurotrophic and monoaminergic modulation
- Non-addictive cognitive support without tolerance development or withdrawal at standard doses
PE-22-28: potential benefits
- Antidepressant-like effects in rodent models of depression (preclinical only)
- Potent, selective inhibition of the TREK-1 (K2P2.1) potassium channel (IC50 ~0.12 nM)
- Rapid-onset (~4-day) antidepressant profile in animals, unlike the multi-week lag of SSRIs
- Increased hippocampal neurogenesis in mice
- Increased cortical synaptogenesis (PSD-95) and BDNF expression in preclinical studies
- No human-validated benefits; not approved for any use (research use only)
Frequently asked
What's the difference between Semax and PE-22-28?
Semax is a nootropics that primary mechanism: multi-pathway neurotrophic activation semax produces its effects through coordinated activation of multiple neurotrophic, neurotransmitter, and neuroprotective…. PE-22-28 is a nootropics that pe-22-28 is a synthetic 7-amino-acid peptide (sequence gvswglr) and a shortened analog of spadin. its proposed mechanism is inhibition of the trek-1 (twik-related k+) channel, a…. The two differ in mechanism, half-life (~2-3 minutes plasma half-life (functional neurological effects persist 12-24 hours due to BDNF/NGF gene expression changes) vs Not characterized in humans. As a small 7-amino-acid peptide a short plasma half-life is expected; in mice the parent peptide spadin lost antidepressant activity by about 7 hours after a single dose, while modified analogs (e.g., G/A-PE 22-28) extended the behavioral effect to roughly 21-23 hours [PMID:28955242].), and typical dose range.
Which has the longer half-life, Semax or PE-22-28?
Semax has a half-life of ~2-3 minutes plasma half-life (functional neurological effects persist 12-24 hours due to BDNF/NGF gene expression changes). PE-22-28 has a half-life of Not characterized in humans. As a small 7-amino-acid peptide a short plasma half-life is expected; in mice the parent peptide spadin lost antidepressant activity by about 7 hours after a single dose, while modified analogs (e.g., G/A-PE 22-28) extended the behavioral effect to roughly 21-23 hours [PMID:28955242].. Longer half-lives generally mean less frequent dosing but slower on/off kinetics.
Which is cheaper, Semax or PE-22-28?
Lowest listed price on BodyHackGuide: Semax from $32.90, PE-22-28 from $49.99. Prices are pulled from the vendor listings tracked on BHG and change frequently. See the compare tables on each compound page for the current set of offers.
Can you stack Semax and PE-22-28?
Stacking depends on mechanism overlap, safety profile, and goals. Semax and PE-22-28 should only be stacked after reviewing each compound's individual protocol page, side effect profile, and any published interaction data. Use the BodyHackGuide stack builder for a structured review before combining research compounds.
See current vendor prices
Listings from the vendors we track. Prices change often, so check the vendor before you buy.
Before you buy Semax or PE-22-28
Check the vendor trust score. Every supplier we track is rated 0-100 on COA verification, payment transparency, shipping, reviews, and listings: one published, reproducible methodology, applied to every vendor.
Related comparisons
Research use only. BodyHackGuide is a research and price-comparison reference. The compounds discussed on this page are not approved by the FDA for human consumption and are sold strictly for laboratory research. Prices shown are pulled from vendor listings tracked on BHG and are subject to change. Every vendor is ranked on the same public, reproducible methodology. See editorial standards and affiliate disclosure.