What Is Semax?
Semax is a synthetic heptapeptide derived from a fragment of adrenocorticotropic hormone (ACTH 4-10). It is studied in preclinical neuro research and is not an FDA-approved drug.
The short answer
Semax was developed in Russia as a modified ACTH(4-10) fragment. Removing the hormone's steroidogenic activity while retaining neuro-associated signaling is the design idea behind it. In the research literature it is studied for neuroprotective and BDNF-associated signaling, and it is the counterpart most often compared with Selank.
Composition and specifications
| Compound | Semax |
|---|---|
| Class | ACTH(4-10)-derived heptapeptide |
| Also known as | CAS 80714-61-0 |
| Sequence / length | Met-Glu-His-Phe-Pro-Gly-Pro (7 amino acids) |
| CAS number | 80714-61-0 |
| Molecular weight | 813.9 g/mol |
| Purity (typical) | ≥99.0% |
| Appearance | White lyophilized powder; water-soluble |
Values above reflect the compound's published specification. As with any research material, the definitive confirmation of identity and purity for a given lot is the mass-spectrometry and HPLC data on its Certificate of Analysis.
How it is described mechanistically
Semax is characterized in research as modulating neurotrophic signaling — notably brain-derived neurotrophic factor (BDNF) and its downstream pathways — without the corticotropic activity of the parent ACTH sequence. It is studied as a neuroprotective and cognition-associated peptide in laboratory models.
What has research examined?
Published Semax work is largely preclinical, with a Russian clinical literature. Areas examined include:
- BDNF and neurotrophic-factor signaling
- Neuroprotection research models (e.g. ischemia models)
- Cognition- and attention-associated research
- Comparisons with Selank
These describe research directions rather than established human effects in the broader clinical literature.
How is it characterized and tested?
Two questions matter most about any peptide sample in a research context: is it the right molecule, and how pure is it. Those are answered by analytical testing — commonly mass spectrometry for identity and HPLC for purity — with both reported on a batch-specific Certificate of Analysis (COA). An independent, published COA lets a researcher confirm identity and purity before beginning work. See peptide handling and storage for how samples are kept stable once received.
Primary literature: browse peer-reviewed studies on Semax at PubMed.
Common questions
Is Semax approved for human use?
Semax is not FDA-approved. It has clinical history in Russia but, in the US context, research-grade material is supplied for laboratory research use only.
What is the difference between Semax and Selank?
Both are Russian-developed research peptides studied for neuro-associated effects, but they derive from different parent molecules — Semax from ACTH(4-10), Selank from the immunopeptide tuftsin — and are studied for different signaling emphases.
How is research-grade Semax stored?
Keep the lyophilized peptide cold, dry, and protected from light, with different handling once reconstituted.