Description
Semax is the short answer to a longer question Russian neuropharmacologists were asking in the 1980s at the Institute of Molecular Genetics in Moscow: could you keep the cognitive and neurotrophic signalling of ACTH(4-10) without the endocrine baggage of the full hormone? The compound they synthesised is a seven-residue peptide, Met-Glu-His-Phe-Pro-Gly-Pro, with a Pro-Gly-Pro tail tacked onto the ACTH(4-7) core to slow enzymatic breakdown. That small modification is most of the story. It is why Semax has a usable in vivo half-life where the parent fragment does not, and it is why so much of the published work uses intranasal delivery in rodents.
The MEHFPGP sequence and what the literature looks at
Research interest in Semax sits in a few clear clusters. The largest is neuroprotection in ischaemia models, where Russian groups have published extensively on transient middle cerebral artery occlusion in rats and on transcriptomic responses after the insult. A second cluster looks at BDNF and TrkB signalling, with Semax raising BDNF expression in hippocampal tissue in several rodent studies. A third sits around attention, memory consolidation, and stress endpoints, which is where the ACTH(4-10) lineage shows up most clearly. There is also a smaller body of work on monoamine turnover and on enkephalinase inhibition, the latter being part of why some papers describe an indirect opioidergic component.
Why labs request this specific peptide
For a research peptide, Semax has an unusually long clinical paper trail outside the West. It is registered in Russia and Ukraine for stroke and cognitive indications, which means there is a body of human pharmacokinetic and tolerability data in Russian-language journals that is rare for a compound at this stage elsewhere. For a lab building comparative nootropic or neuroprotective work, that history is part of the appeal.
Vial contents
- Sealed glass vial of lyophilised Semax, flushed with inert gas before sealing
- Batch-specific Certificate of Analysis with the HPLC chromatogram and mass-spec trace for that lot
- Lot number printed on the vial label, matching the CoA
Purity on our lots runs at 98 percent or better by reverse-phase HPLC, with mass spec confirming the sequence to within 1 Da of the expected 813.9 g/mol. If a vial does not match its CoA on arrival, we refund it. We have not had to do that often, but the policy is real and the inbox that handles it is monitored by a person.
Where we get it and how it ships
Every batch we list comes from a UK or EU contract peptide manufacturer we have audited. We do not list Semax from unverified Asian suppliers because the failure mode is usually silent counter-ion variation and the occasional misidentified sequence, both of which quietly wreck a study. UK orders placed before late afternoon Monday to Thursday are dispatched the same working day, and around nine out of ten arrive within 48 hours.
Bench storage and larger orders
Lyophilised Semax is stable at room temperature for short transit windows but should be moved to a freezer at minus 20 C on arrival for long-term storage. Reconstituted in bacteriostatic water, most labs keep it refrigerated and use it within a couple of weeks where peptide integrity matters for the assay. If you need ten or more vials for a multi-arm protocol or a longer time-course, message support for a custom quote rather than running through the cart. Live chat is staffed by humans during UK working hours, and reconstitution or CoA questions get an answer from someone who handles the stock.
Sold strictly for in vitro laboratory research. Not for human or veterinary use. UK 18+.
