Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Semax and P21 — mechanism, side effects, legal status, and pricing.
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from ACTH(4-10) with a Pro-Gly-Pro C-terminal extension for metabolic stability. It was developed at the Institute of Molecular Genetics (Russian Academy of Sciences) and registered as a drug in Russia in 1994. It is not FDA-approved.
P21 (also P021) is a small peptidergic compound — the tetrapeptide core Asp-Gly-Gly-Leu with an N-terminal acetyl and a C-terminal adamantylated glycine amide (Ac-DGGL(A)G-NH2) — derived from an active region (residues ~148–151) of human ciliary neurotrophic factor (CNTF). It was designed and characterized in the Khalid Iqbal laboratory at the New York State Institute for Basic Research in Developmental Disabilities (NYS IBR). It is an experimental, preclinical compound — NOT FDA-approved and NOT tested in humans in published trials. Distinct from the cyclin-dependent kinase inhibitor protein p21/CDKN1A/WAF1 (a completely different gene product; the two share only the name).
Semax
P21
Category
Legal Status
Mechanism
Half-life
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Semax
P21
COA corpus from Disclosed Labs — independently tested batches only.
Semax
82
COAs
99.5%
Avg purity
16
Labs
P21
2
COAs
99.1%
Avg purity
1
Labs
Semax's evidence base is primarily Russian-language clinical literature. Gusev, Skvortsova and colleagues reported improved neurological recovery in acute hemispheric ischemic stroke when Semax was added to conventional therapy (Zh Nevrol Psikhiatr, 1997; PMID 11517472), and subsequent Russian studies extended use to cerebrovascular insufficiency (PMID 15792140). Preclinical work by Dolotov, Myasoedov and colleagues demonstrated that intranasal Semax rapidly elevates BDNF protein and TrkB activation in rat hippocampus and basal forebrain (Brain Res 2006, PMID 16996037; J Neurochem 2006, PMID 16635254). Genome-wide transcriptional analysis by Medvedeva et al. in rat focal ischemia showed Semax modulates a broad panel of immune-response and vascular-system genes (BMC Genomics 2014, PMID 24661604). Western evidence is limited; Semax has not been evaluated by the FDA and has no pivotal trials in the US or EU.
Key references
Evidence is preclinical (rodent) only. Key publication: Kazim, Blanchard, Dai, Tung, LaFerla, Iqbal & Iqbal, Neurobiology of Disease 2014 (PMID 25046994) reported that chronic oral P021 rescued cognition, boosted dentate-gyrus neurogenesis, and reduced tau hyperphosphorylation in 3xTg-AD mice. Additional preclinical papers from the Iqbal group (and collaborators) have shown dendritic/synaptic rescue in AD and aging rodent models (e.g., Kazim et al., Alzheimer's Res Ther 2017). No Phase 1/2/3 human trials have been published; no human safety or pharmacokinetic data exist. Grey-market vendor material is unvalidated — purity, identity, and dosing are not verifiable.
Semax and P21 are both in the Cognitive category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Key references
Disclosed Labs