Description
Structure & Identity
Semax is a seven-amino-acid peptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues (Met-Glu-His-Phe) are the ACTH(4-7) fragment that gives the molecule its activity; the Pro-Gly-Pro ending is a protective cap that keeps it intact longer. Because that ACTH fragment carries the signaling role without the full hormone attached, Semax lets researchers isolate one narrow slice of the parent hormone’s biology.
Research Background
The bulk of Semax research is preclinical, centered on nerve-growth signaling and how brain tissue holds up under low-oxygen stress.
- ACTH fragment. Semax is an ACTH(4-7) fragment capped with Pro-Gly-Pro for stability [PMID: 24661604].
- Gene-expression response. Genome-wide rat stroke studies tracked how it quiets inflammation genes and activates neurotransmitter genes [PMID: 24661604].
- Protein-level confirmation. Follow-up work measured the protein profile after ischemia [PMID: 34201112].
- Neurotrophin signaling. Research connects it to BDNF and NGF activity in ischemia models [PMID: 39767736].
- Recovery mechanism. Recent work examined its role in functional recovery via the Oprm1 gene [PMID: 40692165].
As with any research peptide, these findings describe an area of study, not an established treatment, and the material supports further laboratory work.
Specifications
| Attribute | Value |
| Chemical name | Semax (Met-Glu-His-Phe-Pro-Gly-Pro) |
| Also Known As | ACTH(4-7)PGP |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro |
| CAS number | 80714-61-0 |
| Molecular formula | C37H51N9O10 |
| Molecular weight | 813.9 g/mol |
| Purity | ≥99% by reverse-phase HPLC |
| Length | 7 amino acids |
| Identity | Confirmed by ESI mass spectrometry |
| Physical form | Lyophilized powder |
| Appearance | White to off-white solid |
| Quantity | 10 mg per vial |
| Storage | -20°C, protected from light |
| Solubility | Soluble in bacteriostatic or sterile water |
| Classification | Research use only |
Storage & Handling
The dry vial holds up well at -20°C when kept out of light, so store it there until use. After you dissolve it, move the solution to 2-8°C and plan to use it within roughly two weeks. Bringing the vial to room temperature before opening reduces moisture pickup, and keeping freeze-thaw cycles to a minimum protects the peptide from breaking down.
Quality Assurance
Every lot of Semax passes through independent quality control before it leaves the facility. Manufacturing follows research-grade standards, and the finished peptide is analyzed by outside laboratories rather than in-house alone: purity by reverse-phase HPLC and identity by mass spectrometry, verified through Janoshik Analytical and US-based labs. A batch-matched certificate of analysis accompanies each vial, tying the purity and identity figures to the material you actually receive.
Frequently Asked Questions
What is Semax used for in research?
Semax is studied mainly in neuroscience research on nerve-growth signaling (BDNF and NGF) and on how brain tissue responds to reduced blood flow in ischemia models. It is a laboratory material and has no approved human use.
How does Semax work?
Research points to Semax raising the activity of neurotrophins like BDNF and NGF and influencing dopamine-related signaling. These effects come from cell and animal studies and describe mechanisms under investigation, not outcomes in people.
Where does Semax come from?
It is a synthetic peptide based on a short fragment of the hormone ACTH, specifically ACTH(4-7), with a Pro-Gly-Pro tail added for stability.
What is the difference between Semax and Selank?
Both are short Russian-developed research peptides, but Semax research is weighted toward cognition and neuroprotection, while Selank research focuses on stress, anxiety, and immune signaling.
Is Semax FDA approved?
No. Semax is an approved medicine in Russia but is not FDA approved in the US, where it is treated as a research-use-only material rather than a drug or supplement.
What are Semax’s molecular weight and sequence?
Its sequence is Met-Glu-His-Phe-Pro-Gly-Pro, its formula is C37H51N9O10, and its molecular weight is about 813.9 g/mol.
What is Semax’s half-life?
Semax has a short measured half-life, which is part of why its stabilizing Pro-Gly-Pro tail is of research interest. This is stated as a scientific property, with no dosing implied.
How do I keep Semax stable, and how is it reconstituted?
Store the powder frozen at -20°C and shielded from light. For research use it is reconstituted with a suitable sterile diluent, then refrigerated at 2-8°C and used within about two weeks.
References
- The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia. 2014. PMID: 24661604.
- Brain Protein Expression Profile Confirms the Protective Effect of the ACTH(4-7)PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia-Reperfusion. 2021. PMID: 34201112.
- ACTH-like Peptides Compensate Rat Brain Gene Expression Profile Disrupted by Ischemia. 2024. PMID: 39767736.
