What Is Semax? Sequence, Identity and Research Reference
Semax identity in brief
Semax is a defined linear heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its one-letter sequence is MEHFPGP. That identity is more precise than broad labels such as “ACTH peptide” or “regulatory peptide,” which describe a relationship or research class rather than the molecule itself.
This reference separates chemical identity, ACTH-related nomenclature, representative experimental evidence, and lot-specific analytical interpretation. Those records answer different questions: a database identity does not authenticate a material, a mass match does not quantify chromatographic purity, and a rat-tissue result does not establish a general biological response.
| Field | Reference value | What the field means |
|---|---|---|
| Standard name | Semax | Common name used in PubChem and the literature |
| Three-letter sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Ordered amino-acid sequence |
| One-letter sequence | MEHFPGP |
Compact sequence notation |
| Residue count | 7 | Semax is a heptapeptide |
| Molecular formula | C37H51N9O10S | PubChem formula for the unmodified neutral sequence |
| Average molecular weight | 813.9 g/mol | PubChem computed average molar mass |
| PubChem CID | 9811102 | NLM compound record |
| CAS Registry Number | 80714-61-0 | Registry identifier associated with Semax |
| Structural description | ACTH(4-7)-Pro-Gly-Pro | The ACTH(4-7) sequence followed by PGP |
These registry values describe the unmodified sequence in the cited PubChem record. A salt, terminally modified analogue, mixture, or mislabeled material should not be assigned the same formula and mass without its own supporting record.
Why Semax has two ACTH-related names
The most structurally explicit name is ACTH(4-7)PGP. Human ACTH residues 4 through 7 are Met-Glu-His-Phe, abbreviated MEHF. Semax places Pro-Gly-Pro after that four-residue segment, producing MEHFPGP.
The phrase ACTH(4-10) analogue describes the reference region to which Semax is related; it does not mean the sequences are identical. PubChem lists native corticotropin(4-10) as MEHFRWG, while Semax is MEHFPGP. They share the first four residues and differ in the final three.
Semax: M E H F P G P
Corticotropin 4-10: M E H F R W G
-------
shared MEHF segmentA finding about full ACTH or native ACTH(4-10) therefore cannot automatically be assigned to Semax. The structural name also does not prove that a supplied sample contains the intended sequence; that requires analytical and traceability records for the sample itself.
What representative Semax studies measure
The accessible Semax literature is dominated by preclinical work, much of it from related Russian research institutions. The studies below are a map of designs and endpoints, not promised effects.
Medvedeva et al., 2014, PMID 24661604
- Experimental system
- Rat cerebral cortex after permanent middle cerebral artery occlusion
- Measured endpoint
- Genome-wide gene-expression changes at two collection times
- Interpretation limit
- Transcript abundance in injured rat cortex does not establish protein activity, functional recovery, or transfer to another model
Sudarkina et al., 2021, PMID 34201112
- Experimental system
- Rat transient cerebral ischemia-reperfusion model; subcortical structures and frontoparietal cortex
- Measured endpoint
- Selected proteins and corresponding transcripts at 24 hours
- Interpretation limit
- The groups were small and the measurements were tissue-, model-, and time-specific
Kolbaev et al., 2025, PMID 41171324
- Experimental system
- Rat hippocampal and cerebellar slice preparations
- Measured endpoint
- Intracellular calcium dynamics in two neuronal preparations
- Interpretation limit
- A slice observation is a narrow cellular result, not a whole-organism or clinical outcome
These papers do not measure the same thing. A broad transcriptional survey, a selected protein panel, and calcium dynamics in tissue slices are separate evidence layers. Agreement at the level of a pathway label is not independent replication of an exact endpoint. The slice study also reported nonuniform observations across preparations, so negative or unchanged endpoints should remain visible.
For an attempted replication, the original paper remains controlling. Match the exact sequence, material description, comparator, model, tissue, collection time, assay, and statistical plan.
How to verify a current Semax lot
A registry record answers what the name Semax denotes. A lot record answers what a testing laboratory reported for one submitted sample. Connecting the two requires a matching product name, physical lot code, report identifier, and complete analytical record.
Start with BulkGLP’s current and historical batch records. Match the lot printed on the material to the lot shown on the report, then check which attributes the laboratory actually tested. Identity by LC-MS, chromatographic purity by HPLC-UV, and quantitative content are separate results; none substitutes for the other two. The peptide COA guide explains those fields and their limits.
Do not carry a result forward to a later lot. A report supports only the submitted sample and traceability chain it identifies.
What LC-MS and HPLC do not prove on their own
An intact-mass match can support the expected molecular identity, but closely related sequences, positional isomers, terminal modifications, or coexisting species may require tandem mass spectrometry, peptide mapping, or another orthogonal method. The method description and underlying spectrum matter.
HPLC-UV is a separation and relative-response measurement. Its result depends on the column, mobile phase, gradient, detector wavelength, sample preparation, peak assignment, and integration rules. A high main-peak area is not proof of sequence identity, net peptide content, sterility, or performance in a biological assay.
Traceability is separate again. Even a technically sound report does not establish the material in hand if the lot on the material and the lot on the report do not match.
Semax reference questions
What is the amino-acid sequence of Semax?
Semax is Met-Glu-His-Phe-Pro-Gly-Pro, abbreviated MEHFPGP. PubChem lists it as a seven-residue peptide with formula C37H51N9O10S and average molecular weight 813.9 g/mol.
Is Semax identical to native ACTH(4-10)?
No. Native corticotropin(4-10) is MEHFRWG; Semax is MEHFPGP. “ACTH(4-10) analogue” describes a structural relationship, while ACTH(4-7)PGP states the Semax composition more directly.
Does a Semax LC-MS result establish purity?
No. LC-MS identity and HPLC-UV chromatographic purity answer different questions. Quantitative content and lot traceability are separate again.
Do the cited studies establish a human outcome?
No. The representative studies summarized here use rat brain tissue, rat disease models, or rat brain-slice preparations and report molecular or cellular endpoints. They do not support a personal-use prediction.
Does one lot’s purity result apply to every Semax lot?
No. It applies to the submitted sample identified by that report. A later lot requires its own matching record.