Semax: Research Reference
Research Use Only. This page is a technical reference for in-vitro laboratory research. Reserve Research compounds are not for human or veterinary use, and nothing here is guidance for administration of any kind.
In simple words
Semax is a chain of 7 amino acids. It is made in a lab. The first part is a small piece of a hormone called ACTH. The end part helps it last longer.
Scientists use it in the lab to study genes in the brain, like the one for a growth helper called BDNF.
Reserve Research sells Semax only for lab research. See Semax on our product page →
Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro. Its first four residues are the ACTH(4–7) fragment of adrenocorticotropic hormone, followed by a Pro-Gly-Pro tail that slows breakdown by peptidases. It was developed in Russia (Institute of Molecular Genetics, Russian Academy of Sciences) and first described in the literature around 1991. Laboratories use it to study neurotrophin gene expression, such as BDNF and its receptor TrkB, and genome-wide transcription in rodent brain. Its CAS number is 80714-61-0, its formula is C37H51N9O10S, and its molecular weight is about 813.9 g/mol.
Semax key facts
| Name | Semax |
|---|---|
| Synonyms | ACTH(4–7)-Pro-Gly-Pro, MEHFPGP |
| Compound class | Synthetic heptapeptide; ACTH fragment analogue (no corticotropic activity of full ACTH) |
| Sequence | M-E-H-F-P-G-P (Met-Glu-His-Phe-Pro-Gly-Pro), free termini |
| CAS number | 80714-61-0 |
| Molecular formula | C37H51N9O10S |
| Molecular weight | ≈813.9 g/mol (free peptide) |
| Origin | Institute of Molecular Genetics, Russian Academy of Sciences |
| Appearance | White lyophilized powder |
| Solubility | Water-soluble |
| Storage (lyophilized) | −20 °C, dry, protected from light |
Structure
Full ACTH is a 39-residue hormone. Short N-terminal fragments such as ACTH(4–10) (Met-Glu-His-Phe-Arg-Trp-Gly) were studied for decades because they keep some activities of the parent hormone without stimulating the adrenal cortex. Semax keeps the ACTH(4–7) core, Met-Glu-His-Phe, and replaces the rest with Pro-Gly-Pro for stability. The methionine makes Semax sensitive to oxidation, so solutions should be protected from air and light.
Mechanisms studied in research models
- BDNF and TrkB expression. In rats, Semax increased BDNF and TrkB mRNA and BDNF protein in the hippocampus (Dolotov et al., 2006).
- Genome-wide transcription. In a rat model of focal cerebral ischemia, genome-wide analysis showed Semax changed expression of genes related to the immune and vascular systems (Medvedeva et al., 2014).
- Related peptide. Semax shares its Pro-Gly-Pro tail with Selank, a tuftsin analogue from the same institute.
Laboratory handling and storage
- Lyophilized powder: store at −20 °C, sealed and dry, away from light. Let the vial reach room temperature before opening.
- Solvent: water-soluble. Labs commonly use sterile bacteriostatic water for multi-use stock solutions.
- Prepared solutions: keep at 2–8 °C, minimize headspace and light exposure (methionine oxidizes), and avoid repeated freeze–thaw cycles.
What a Semax certificate of analysis should show
- Identity: mass consistent with ≈813.9 g/mol. A peak 16 mass units higher suggests oxidized methionine.
- Purity: chromatographic purity reported for the specific batch.
- Batch traceability: a lot number that matches the vial label.
Every Reserve Research batch is tested by an independent lab. You can look up any batch number on our COA verification page.
Frequently asked questions
What is Semax?
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) built from the ACTH(4–7) fragment plus a Pro-Gly-Pro tail. Laboratories use it to study BDNF/TrkB expression and gene transcription in rodent brain.
What is the CAS number for Semax?
80714-61-0.
What is the molecular weight and formula of Semax?
C37H51N9O10S, with a molecular weight of about 813.9 g/mol.
Is Semax the same as ACTH?
No. It contains only four residues of ACTH (positions 4–7) and does not have full ACTH’s activity on the adrenal cortex.
What is the difference between Semax and Selank?
Both end in Pro-Gly-Pro, but Semax is built on ACTH(4–7) (MEHF) and Selank on tuftsin (TKPR). They are different peptides with different research uses.
How should Semax be stored?
Store the lyophilized powder at −20 °C, dry and protected from light. Keep reconstituted solutions at 2–8 °C, limit air exposure, and avoid repeated freeze–thaw cycles.
Is Reserve Research Semax sold for laboratory research only?
Yes. It is sold strictly for in-vitro laboratory research. It is not a drug or supplement, and it is not for human or veterinary use.
Research-grade Semax from Reserve Research
Semax is supplied as a lyophilized powder in sealed vials, independently tested batch by batch, with the COA available through the product page and /verify. Related: Selank reference and bacteriostatic water.
References
- Dolotov OV, et al. Brain Research. 2006;1117:54–60. doi:10.1016/j.brainres.2006.07.108
- Medvedeva EV, Dmitrieva VG, Povarova OV, et al. BMC Genomics. 2014;15:228. doi:10.1186/1471-2164-15-228
Last reviewed: October 2026. This page summarizes published laboratory literature for reference. It makes no claims about the safety or effectiveness of any compound in humans or animals.