AOD9604
A C-terminal growth hormone fragment studied for metabolic activity without the receptor engagement of the full hormone.
Synthetic ACTH(4-10) fragment analogue
Semax
ACTH(4-7)-PGP
An ACTH fragment analogue studied for neurotrophic signalling without corticotropic activity.
Research use only. This compound is supplied for laboratory
research and analytical use. It is not a medicine, not a supplement and
not for human or veterinary consumption. Several research peptides are prohibited in sport under WADA Section S2.
Chemical identity
Semax is the ACTH(4-7) fragment — Met-Glu-His-Phe — extended with the same Pro-Gly-Pro stabilising tail used in Selank. The parent fragment is the region of adrenocorticotropic hormone associated with behavioural rather than adrenal effects, and truncating at residue 7 removes the sequence required for corticotropic activity.
This is the compound's design premise: the neuroactive portion of ACTH without the hormonal one. Semax does not stimulate cortisol release, which is the finding that made it interesting as a probe.
The N-terminal methionine is oxidation-prone. Methionine sulfoxide formation is the principal degradation route and should be treated as the controlling stability parameter.
Mechanism in research models
The most reproducible molecular finding is rapid upregulation of BDNF and its receptor TrkB in rat hippocampus, reported within hours of administration. BDNF/TrkB signalling supports synaptic plasticity and neuronal survival, which provides a coherent mechanistic basis for the behavioural results.
Additional reported effects include modulation of dopaminergic and serotonergic transmission, changes in the expression of neurotrophin-associated genes, and inhibition of enkephalin degradation — the same enkephalinase mechanism described for Selank, unsurprising given the shared Pro-Gly-Pro tail.
Semax is not a melanocortin receptor agonist in the way MT-2 or PT-141 are, despite the shared ACTH ancestry. The truncation removes the core melanocortin pharmacophore.
What the literature establishes
The BDNF findings in rodent models are the strongest part of the evidence base, replicated across several laboratories and supported by gene-expression data rather than behaviour alone.
Semax is registered in Russia for cerebrovascular and cognitive indications, and the clinical literature supporting that registration is subject to the same limitations as Selank's: small trials, limited blinding, minimal independent replication outside the originating country.
For a research plan, the useful framing is that Semax has a well-supported molecular effect (BDNF upregulation in rodents) and poorly supported clinical claims. Design around the former.
Handling, reconstitution and storage
Storage and handling. Follow the approved conditions stated on the current lot-specific certificate of analysis and safety data sheet. The notes below describe general laboratory practice for this class of material and do not override the lot documentation. Contact research@apexscienceslabs.com before ordering if those documents are not available.
Lyophilised material is typically held sealed and desiccated at −20 °C with air exposure minimised; confirm the validated condition on the lot documentation. The N-terminal methionine makes oxygen exclusion a functional requirement — briefly opened vials left at ambient temperature will oxidise.
Freely water-soluble. Reconstitute with sterile or bacteriostatic water without solvent assistance.
Aliquot immediately and freeze. Oxidised material shows no visual change, so there is no way to detect degradation without analysis — which makes disciplined storage the only practical control.
Analytical documentation
Require RP-HPLC purity and an observed mass. For Semax specifically, ask whether the methionine sulfoxide peak is quantified — it is the impurity that matters, it forms after manufacture, and it is not always reported.
A mass 16 Da above the expected value indicates a single oxidation. If your own analysis shows that shift, the material has degraded in storage or transit regardless of what the incoming certificate said.
References and authoritative sources
Chemical identity, regulatory status and anti-doping classification should be confirmed against primary sources rather than against this page. The records below are the ones to check first.
These are database and regulatory sources. Citations to specific primary papers are being added to this page as part of ongoing scientific review; until they appear, treat the mechanism and literature sections above as a summary to verify rather than a citation of record.
Editorial accountability
Written by Apex Sciences Labs editorial teamNot yet attributed to a named author
Scientific review Pending named reviewThis page has not yet been reviewed by a named, credentialled reviewer
Published August 26, 2026First publication of this page
Last reviewed September 22, 2026Identity, mechanism, literature limitations, handling statements and references.
Found an error? Report it to research@apexscienceslabs.com — see our corrections policy and editorial policy.
Sourcing partner
Avid Peptides supplies Semax and the rest of our peptide range
Apex Sciences Labs publishes the specification and handling documentation. Fulfilment for research peptides is handled by Avid Peptides, who supply lyophilised material against batch certificates with RP-HPLC purity and mass-spectrometry identity confirmation. Request the certificate for the specific batch before ordering — not a representative example.
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Next step
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