What is semax, and what is it studied for?
Semax is the heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro, formula C37H51N9O10S, mass 813.9: the ACTH(4-7) fragment joined to a Pro-Gly-Pro tail that was added for stability. It was developed in Russia, where a nasal pharmaceutical form is registered, and is studied in cell and rodent models for effects on neurotrophin expression. The material here is for in-vitro research only.
What is the structure of Semax?
Seven residues with free termini: a methionine at the N-terminus, a histidine, a phenylalanine and a proline-rich tail. The methionine makes it oxidation-prone and the histidine makes its charge pH-dependent. The N-acetyl, C-amidated analogue sold separately is a different molecule with a different mass; the certificate's identity line distinguishes them.
| Identifier | Value |
|---|---|
| Molecular formula | C37H51N9O10S |
| Molecular weight | 813.9 g/mol |
| Residues | 7 |
| CAS number | 80714-61-0 |
| PubChem CID | 9811102 |
| Current lot | SEMX10-0803 |
How is Semax thought to work?
Semax is not a melanocortin receptor agonist in the usual sense despite its ACTH origin. The best-characterised finding is an increase in BDNF and its receptor TrkB expression in rat hippocampus, reported by Dolotov and colleagues in 2006, with downstream effects on neuronal survival in cell models. Receptor-level mechanism is not established.
Which research areas use Semax?
| Area | Typical models and endpoints |
|---|---|
| Neurotrophin expression | BDNF and TrkB transcript and protein readouts in rodent hippocampus and neuronal cultures. |
| Neuronal survival | Oxidative and ischaemic stress models in cultured neurons. |
| Peptide stability | The Pro-Gly-Pro tail as a case study in designed protease resistance; methionine oxidation as a degradation route. |
| Analogue comparisons | Semax against N-acetyl semax amidate and selank in the same assays. |
What does the published literature show?
Dolotov et al. (Brain Research, 2006) reported BDNF and TrkB regulation in rat hippocampus. A large body of Russian-language work describes the registered nasal product in clinical settings; those reports concern a pharmaceutical product and are not evidence about the material sold here. No FDA or EMA approval exists, and research use is in-vitro and preclinical.
How is Semax handled in the laboratory?
Dissolves readily in water. Contains methionine: protect from light and air, minimise headspace, and expect an oxidised impurity to grow in solutions kept too long. Store lyophilized at minus 20 °C; aliquot and freeze solutions. The concentration table covers volumes and syringe units; the storage guide covers stability by compound class.
What does the current certificate show?
Lot SEMX10-0803 tested at 99.82% purity by RP-HPLC (214 nm), identity confirmed by LC-MS/MS, endotoxin <0.05 EU/mL. The certificate is in the COA library and the lot number on the vial matches it. Sold as 10 mg per vial at $65, for laboratory research only.
Certificate history for Semax
Every certificate the library holds for this compound, newest first. A replaced lot stays listed so the history can be read; the certificate dataset reads all 114 together.
| Lot | Issued | Size | Identity | Purity | Content | Status |
|---|---|---|---|---|---|---|
| SEMX10-0803 | Aug 17, 2026 | 10 mg | LC-MS/MS | 99.82% | 10.50 mg | Current |
| SEMX10-0528 | Jun 17, 2026 | 10 mg | MALDI-MS | 99.9% | 10.68 mg | Replaced |
| SEMX10-0318 | Apr 3, 2026 | 10 mg | MALDI-MS | 99.8% | 11.26 mg | Replaced |
Frequently asked questions
What is the difference between semax and N-acetyl semax amidate?
The amidate is capped at both ends, acetyl at the N-terminus and amide at the C-terminus, which changes the mass by about 41 daltons and the charge at both termini. They are separate catalogue items with separate certificates.
What does the current certificate show?
Lot SEMX10-0803: identity by LC-MS/MS at 813.9, purity 99.82% by RP-HPLC at 214 nm, content 10.50 mg, endotoxin below 0.05 EU/mL. Issued 17 August 2026.
Why does semax share a bottle with selank in one product?
Because they are studied together as two short regulatory peptides with different parent sequences; the blend post explains what the certificate of a two-peptide vial shows.
References
- Dolotov OV, Karpenko EA, Inozemtseva LS, et al. Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006;1117(1):54-60.
- Ashmarin IP, Nezavibatko VN, Myasoedov NF, et al. A nootropic adrenocorticotropin analog 4-10-semax (15 years experience in its design and study). Zh Vyssh Nerv Deiat Im I P Pavlova. 1997;47(2):420-430.
- PubChem CID 9811102, Semax. National Library of Medicine. Read 2 October 2026.
Clinical results cited above describe regulated trials of pharmaceutical products and are given as context for research interest only. Nothing on this page describes or recommends use of the material sold here in humans or animals.
Semax 10 mg
$65 per vial
Lot SEMX10-0803 · 99.82% RP-HPLC (214 nm) · certificate published
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