PE-22-28 vs Semax
Side-by-side comparison of PE-22-28 and Semax: mechanism, half-life, dose range, safety profile, and vendor pricing.
Price snapshot
PE-22-28
Semax
PE-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: $54.99 across 1 listing
Full PE-22-28 profileSemax
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 profileSide-by-side comparison
| Attribute | PE-22-28 | Semax |
|---|---|---|
| Category | Nootropics | Nootropics |
| Research Stage | Preclinical | Approved (Russia, since mid-1990s for stroke and cognitive disorders) |
| Mechanism of Action | 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.… | 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… |
| Half-Life | 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]. | ~2-3 minutes plasma half-life (functional neurological effects persist 12-24 hours due to BDNF/NGF gene expression changes) |
| Typical Dose Range | 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). | 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 |
| Dosing Frequency | Once daily or every other day (research-chemical community protocols; no validated clinical dosing schedule). | Intranasal 1–3 times daily |
| Administration | — | Intranasal |
| Side Effects | 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… | 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… |
| Molecular Weight | 773.9 g/mol | 813.9 Da |
| Common Vial Sizes | — | 5mg, 10mg |
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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)
Semax: 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
Frequently asked
What's the difference between PE-22-28 and Semax?
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…. Semax is a nootropics that primary mechanism: multi-pathway neurotrophic activation semax produces its effects through coordinated activation of multiple neurotrophic, neurotransmitter, and neuroprotective…. The two differ in mechanism, half-life (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]. vs ~2-3 minutes plasma half-life (functional neurological effects persist 12-24 hours due to BDNF/NGF gene expression changes)), and typical dose range.
Which has the longer half-life, PE-22-28 or Semax?
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].. 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). Longer half-lives generally mean less frequent dosing but slower on/off kinetics.
Which is cheaper, PE-22-28 or Semax?
Lowest listed price on BodyHackGuide: PE-22-28 from $54.99, Semax from $32.90. 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 PE-22-28 and Semax?
Stacking depends on mechanism overlap, safety profile, and goals. PE-22-28 and Semax 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.
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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.