For research purposes only. This guide describes the chemical identity and laboratory handling of Semax and summarises findings reported in published research. It is not medical advice and does not describe any effect, dose, or use in humans or animals.
What is Semax?
Semax is a synthetic heptapeptide (seven amino acids) with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP), structurally related to a fragment of ACTH(4-10). It is supplied as a lyophilised powder for laboratory research.
PurePeptides offers Semax at >99% purity strictly for in-vitro research use. This page describes its chemical identity and handling only.
Semax is a synthetic heptapeptide derived from the ACTH(4-10) fragment, with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP). It originates from Russian neuropeptide research, where peptides based on short ACTH fragments have been studied in experimental nervous-system models. The Pro-Gly-Pro tail, added relative to native ACTH(4-10), is associated in the literature with greater stability against enzymatic breakdown.
Chemical identity & specifications
| Product | Semax |
| Classification | Synthetic heptapeptide (ACTH(4-10) fragment analogue) |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP) |
| Molecular weight | ~813.9 g/mol |
| CAS number | 80714-61-0 |
| Solubility | Water-soluble |
| Purity | >99% |
| Physical form | Lyophilised powder |
| Storage | -20°C lyophilised; 2-8°C reconstituted |
| Intended use | Research use only - not for human consumption |
Handling Semax in research protocols
In laboratory settings, lyophilised Semax is typically stored at -20°C, protected from light and moisture, until use. For reconstitution, bacteriostatic water is a commonly cited solvent; once in solution, the material is generally kept refrigerated at 2-8°C with freeze-thaw cycles minimised to preserve peptide integrity.
Researchers quantify Semax by concentration within their experimental system — for example molar concentrations for in-vitro work, or amount-per-mass figures in animal models. These are parameters defined by the study design and reported in the literature; they are not dosing guidance for any human or animal use. To convert between vial mass, solvent volume, and target concentration for laboratory preparation, our peptide reconstitution calculator may be useful.
Findings reported in the research literature
Semax appears in neuropeptide research literature, primarily in in-vitro and animal-model studies of the ACTH(4-10) fragment family and related neurotrophic signalling. It is referenced as a synthetic reference compound within this niche of the literature.
Any effects described in this literature are observations made in controlled experimental systems — cell assays and animal models — and are reported here only to summarise the scientific record. They do not constitute claims about outcomes, efficacy, benefits, or safety in humans, and nothing on this page should be read as encouraging human or animal use. Readers interested in the primary research can review the indexed literature via PubMed’s Semax results.
Semax and Selank: synthetic neuropeptides
Semax is frequently discussed alongside Selank. Both are synthetic heptapeptides from the same lineage of Russian neuropeptide research, but they derive from different parent sequences:
| Peptide | Sequence | Based on | Approx. MW |
| Semax | MEHFPGP | ACTH(4-10) fragment | ~813.9 g/mol |
| Selank | TKPRPGP | Tuftsin | ~751.9 g/mol |
For the companion compound, see our Selank research guide. Both are supplied by PurePeptides strictly as research materials, with no claim regarding outcomes in humans or animals.
Purity and quality control in research-grade Semax
In laboratory research, peptide purity has a direct bearing on reproducibility: synthesis by-products or residual reagents can confound experimental observations. PurePeptides supplies Semax at greater than 99% purity as a lyophilised powder.
In peptide manufacturing, purity is typically assessed by reverse-phase high-performance liquid chromatography (HPLC), while identity is confirmed by mass spectrometry (MS) against the expected molecular weight — approximately 813.9 g/mol for Semax. A certificate of analysis (COA) documenting these results is available on request for the current batch. When evaluating any research-grade peptide, requesting the COA and confirming both the purity figure and the mass-spec identity is good laboratory practice.
Frequently asked questions
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP), related to a fragment of ACTH(4-10), supplied as a lyophilised powder for research use only.
Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP), a chain of seven amino acids.
Both are synthetic heptapeptides from Russian neuropeptide research, but Semax is based on the ACTH(4-10) fragment (sequence MEHFPGP) while Selank is based on the peptide tuftsin (sequence TKPRPGP).
PurePeptides supplies Semax at greater than 99% purity as a lyophilised powder. A certificate of analysis (COA) is available on request for the current batch.
Store the lyophilised powder at -20°C, protected from light and moisture. In the laboratory it is commonly reconstituted with bacteriostatic water; once in solution, store refrigerated at 2-8°C and minimise freeze-thaw cycles.
Research-grade Semax is available from PurePeptides at greater than 99% purity, with same-day dispatch before 3PM and tracked UK & EU delivery. It is sold strictly for laboratory research use only.
Related comparisons
Research-grade Semax
Greater than 99% purity, lyophilised powder, same-day dispatch before 3PM with tracked UK & EU delivery. Research use only.
Buy Semax →Disclaimer: All products supplied by PurePeptides are strictly for laboratory research use only. They are not for human or animal consumption and are not medical products. This guide is informational and summarises publicly available research; it is not medical, clinical, or dosing advice.