Acetylated/amidated Semax analog (Ac-MEHFPGP-NH₂). Longer half-life than plain Semax. Distinct compound, not an alias.
Last Updated: May 2026
N-Acetyl Semax Amidate (Ac-MEHFPGP-NH₂) is a structural analog of Semax with N-terminal acetylation and C-terminal amidation modifications that confer enhanced enzymatic stability and longer half-life. It is a distinct compound from native Semax — not an alias — though the two are closely mechanistically related. N-Acetyl Semax Amidate is not approved by any major regulator and is sold as a research-use-only compound by third-party laboratories.
N-Acetyl Semax Amidate is Semax (Met-Glu-His-Phe-Pro-Gly-Pro) with two structural modifications: N-terminal acetylation (Ac-) and C-terminal amidation (-NH₂), which together confer resistance to aminopeptidase and carboxypeptidase degradation and extend half-life relative to native Semax. The pharmacological effects are similar to Semax — BDNF upregulation, neuroprotection, cognitive performance effects — but the longer half-life supports less-frequent dosing in research protocols. Evidence level: Preclinical (rodent cognition, BDNF effects); Russian research contexts; no Western Phase 2/3 RCT.
Preclinical rodent studies have shown effects on BDNF expression, cognitive performance markers, and neuroprotection in ischemic models similar to but with longer-duration effects than native Semax. Russian research has explored the modified analog as a potential improvement on the Semax pharmacokinetic profile. Formal Phase 2/3 clinical evidence at Western standards is not available. Evidence level: Preclinical; Russian research; FDA-grade Phase 2/3 not conducted.
N-Acetyl Semax Amidate is the longer-acting structural analog of Semax, sharing the parent compound's mechanism with extended duration per dose.
| Compound | Modifications | Half-life | Approved status |
|---|---|---|---|
| Semax | None (native ACTH(4-10) heptapeptide) | Shorter | Approved (Russia) |
| N-Acetyl Semax Amidate | N-terminal acetyl + C-terminal amide | Longer | Research-use only |
| Selank | Tuftsin-derived heptapeptide | Moderate | Approved (Russia) |
Side effects in available preclinical data and community-reported research use are mild — generally similar to Semax with occasional mild stimulation effects. Long-term safety in humans at sustained research-use dosing is not characterized at Western RCT standards. Evidence level: Preclinical safety; human long-term unestablished.
N-Acetyl Semax Amidate is not approved for any medical indication anywhere in the world as of May 2026. Unlike native Semax (which was removed from FDA Category 2 in April 2026), the modified analog was not specifically included in the April 22, 2026 Category 2 removals or PCAC review schedule. Regulatory context in FDA peptide regulation 2025–2026 timeline.
The structural similarity between N-Acetyl Semax Amidate (Ac-MEHFPGP-NH₂) and native Semax (MEHFPGP) creates a substantial mislabeling risk — the modifications add ~70 Da to the molecular weight, which mass spectrometry can distinguish, but basic HPLC may not. Independent third-party HPLC with mass spectrometry identity confirmation is essential. Buyers paying for "N-Acetyl Semax Amidate" should verify they are not receiving native Semax (which is typically cheaper). Guidance in how-to-test-peptides hub.
Peptigrity purchases N-Acetyl Semax Amidate vials anonymously at standard customer pricing, sends them to ISO-accredited third-party labs for HPLC and mass spectrometry analysis, and publishes the unedited certificate of analysis. Mass spec is particularly important to verify the acetyl and amide modifications. Methodology in how we calculate trust scores.
No. N-Acetyl Semax Amidate is a structural analog of Semax with N-terminal acetylation and C-terminal amidation modifications. They are different molecules with related effects; the modified analog has longer half-life. They are not aliases or interchangeable products.
N-Acetyl Semax Amidate is legal to purchase as a research chemical for laboratory use in most jurisdictions, but it is not approved for human consumption. Country breakdown in peptide legal status guide.
No active FDA approval pathway exists for N-Acetyl Semax Amidate as of May 2026. Unlike native Semax (which is in PCAC review for July 2026), the modified analog was not specifically included in the April 2026 Category 2 removals.
Independent third-party HPLC certificate of analysis from a lab the vendor does not own or pay, with mass spectrometry identity confirmation to verify the acetyl and amide modifications. This is essential because basic HPLC may not distinguish N-Acetyl Semax Amidate from native Semax. COA interpretation in red flags in peptide certificates of analysis.
No. N-Acetyl Semax Amidate is not approved for human consumption and Peptigrity is an independent review platform, not a medical authority. Research-use dosing in community protocols varies. Anyone considering use should consult a licensed physician.
The primary practical difference is half-life — the modified analog requires less-frequent dosing for sustained effects. Russian clinical practice has favored native Semax for established approved indications; the modified analog is more typically used in research and community contexts where dosing convenience matters.
This section is for educational and informational purposes only and does not constitute medical advice. N-Acetyl Semax Amidate is not approved by the FDA or any major Western regulator for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.
Real protocols and questions from members — independent of vendors, never sponsored.
Sign in to ask a question.
Every submitted test helps the community verify purity across brands. Free, fast, independent.