Neuropeptides
Semax
ACTH 4-7 with a Pro-Gly-Pro tail
Identity
- Class
- Neuropeptides
- Molecular weight
- 814 Da
- Residues
- 7
- Heavy atoms
- 107
- Reference slug
- semax
These are published properties of the molecule, given for identification. Values we cannot confirm are omitted rather than estimated. What these terms mean.
What this compound is
A seven-residue peptide: the four-residue ACTH fragment with a proline-glycine-proline extension. The proline-rich tail is why the backbone is modelled in a polyproline-II conformation rather than a helix.
Sequence
| 1 | MEHFPGP |
|---|
- Three-letter code
- Met-Glu-His-Phe-Pro-Gly-Pro
The one-letter code gives the amino-acid backbone. Terminal modifications, where a compound carries them, are accounted for in the molecular weight above but are not visible in the letters.
Residue composition
Counted directly from the sequence above. Semax is built from 6 of the twenty standard amino acids across 7 positions.
By residue
| Residue | Code | Count | Share |
|---|---|---|---|
| Proline | P · Pro | 2 | 28.6% |
| Glutamic acid | E · Glu | 1 | 14.3% |
| Phenylalanine | F · Phe | 1 | 14.3% |
| Glycine | G · Gly | 1 | 14.3% |
| Histidine | H · His | 1 | 14.3% |
| Methionine | M · Met | 1 | 14.3% |
By side-chain class
Nonpolar, aliphatic
4 · 57.1%
G M P
Aromatic
1 · 14.3%
F
Positively charged
1 · 14.3%
H
Negatively charged
1 · 14.3%
E
Side-chain classes follow the standard grouping of the twenty proteinogenic amino acids. Composition is arithmetic over the published sequence and says nothing about how the molecule behaves.
Primary literature
4 peer-reviewed papers indexed in PubMed that name this compound in the title. Each record was checked against the database for title, journal and year rather than written from memory.
Semax peptide targets the μ opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice
Br J Pharmacol2025PMID 40692165
Semax and Pro-Gly-Pro activate the transcription of neurotrophins and their receptor genes after cerebral ischemia
Cell Mol Neurobiol2010PMID 19633950
The Effect of Peptide Semax, an ACTH(4-10) Analogue, on Intracellular Calcium Dynamics in Rat Brain Neurons
Bull Exp Biol Med2025PMID 41171324
The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis
BMC Genomics2014PMID 24661604
Citations are listed so the underlying research can be read directly. They describe laboratory and preclinical work on the molecule. They are not evidence of a benefit, and nothing here is an application, dose, route or outcome.
Reference databases
PubChem
Compound record: ACTH (4-7), Pro-Gly-Pro-
Resolved from the compound name
PubMed
Indexed literature
Live search for Semax
Links resolved against the live databases on 2026-08-29.
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This is a reference entry. Sequence, residue count, molecular weight and atom count are published properties of the molecule, given for identification. Nothing on this page describes an application, benefit, dose, route or outcome, and nothing here should be read as an offer to supply or as guidance for use in a person or an animal. Materials sold by PepXtide are for laboratory research use only, are not for human or animal consumption, and have not been evaluated by the FDA.