Semax
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) that is an analogue of the adrenocorticotropic hormone fragment ACTH(4-10) with a Pro-Gly-Pro tail.
- TypePeptide
- FormulaC37H51N9O10S
- Average mass813.92 g/mol
- CAS80714-61-0
- Vesta listings3
Reference page for laboratory use · updated 2026-10-30
Overview
Semax at a glance
Semax was developed in Russia and is described in many publications in rodent and cell models, including studies of its binding sites in the brain and effects on monoaminergic systems.
Like Selank, it uses the Pro-Gly-Pro tail to improve stability.
Structure
The N-terminal methionine can oxidise to the sulfoxide. The calculated formula matches PubChem exactly.
Identity
Identity data
| Name | Semax |
|---|---|
| Also written as | ACTH(4-10)Pro-Gly-Pro |
| Type | Peptide |
| Research area | Neuropeptide-derived peptides |
| Molecular formula | C37H51N9O10S |
| Monoisotopic mass | 813.3480 Da |
| Average molecular weight | 813.92 g/mol |
| CAS number | 80714-61-0 |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro |
| PubChem record | CID 9811102 |
The formula was calculated independently from the written sequence and matches the PubChem record exactly. Reference data retrieved on 2026-10-30. Compare these values with the batch certificate of analysis, using the compound identity file template.
Expected values
Mass spectrometry reference
Ions calculated from the monoisotopic mass 813.3480 Da. Use them to check an LC-MS result; for larger peptides the instrument usually reports a deconvoluted mass close to 813.9 Da instead.
| Ion | m/z |
|---|---|
| [M+H]+ | 814.3553 |
| [M+2H]2+ | 407.6813 |
| [M+Na]+ | 836.3372 |
| [M+K]+ | 852.3112 |
Read the guide to average and monoisotopic mass for how these values are calculated.
Quality
Analytical notes for batch documents
- Methionine sulfoxide (+15.995 Da) is the most likely degradation product to check for.
- Vesta lists Semax alone and in a blend with Selank.
- Mass shifts to look for in this sequence: methionine oxidation (+15.995 Da).
- The molecular weight of a vial of powder includes counter-ions and water; the share of the powder that is peptide is the net peptide content.
Vesta listings
Semax formats and prices
Research blends that contain Semax
| Product | Per vial | SKU | Price per kit | Price per vial |
|---|---|---|---|---|
| Semax10mg+Selank10mg | 20 mg | XS20 | $160.45 | $16.04 |
Prices are per kit of 10 vials in US dollars. Shipping is paid by the customer and is shown in the cart. Volume savings of 5 %, 8 % and 10 % apply from $350.00, $600.00 and $1,000.00. See the full price list.
Published literature
Selected scientific literature
Bibliographic details were read from PubMed on 2026-10-30. The papers are listed for scientific reference; Vesta makes no claim about the use of its research materials in people or animals.
- Specific binding of semax in different regions of the rat brainV'yunova TV, Shevchenko KV, Shevchenko VP et al. · Dokl Biol Sci · 2006 · PMID 17278839
- Effects of Semax on dopaminergic and serotoninergic systems of the brainEremin KO, Kudrin VS, Grivennikov IA et al. · Dokl Biol Sci · 2004 · PMID 15088389
Questions
Frequently asked questions
What is Semax?
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) that is an analogue of the adrenocorticotropic hormone fragment ACTH(4-10) with a Pro-Gly-Pro tail.
What is the molecular weight of Semax?
Semax has the formula C37H51N9O10S, an average molecular weight of 813.92 g/mol and a monoisotopic mass of 813.3480 Da. A salt form, a different counter-ion or a metal complex changes the molecular weight printed on a certificate of analysis, so compare like with like.
How can I check the identity of a batch of Semax?
Compare the intact mass measured by LC-MS with the expected values on this page, for example [M+2H]2+ at m/z 407.6813. Confirm that one main HPLC peak carries that mass and that the batch code on the report matches the vial. The guides on mass spectrometry and on certificates of analysis explain each step.
Which Semax products does Vesta list?
Vesta lists 3 products for Semax: 5 mg, 10 mg per vial in kits of 10 vials, plus 1 research blend that contain it. Prices are shown per kit in US dollars, and shipping is paid by the customer.