Semax UK — ACTH(4-10) Analogue Research Guide

ACTH(4-10) is a seven-residue fragment of adrenocorticotropic hormone. On its own it is broken down within minutes and carries hormonal activity that makes it unsuitable for neurological research. Semax attaches a Pro-Gly-Pro tail to the C-terminus, which strips out the hormonal effect and dramatically slows enzymatic degradation.

• Parent structure: ACTH(4-10), a natural melanocortin fragment
• Modification: added Pro-Gly-Pro tail for protease resistance
• Class: regulatory / nootropic research peptide
• Typical supply: 10mg lyophilised vial

That stability is the whole point of the molecule — it is what turned a transient hormone fragment into something with a long enough half-life to study.

The bulk of the published Semax literature centres on BDNF — brain-derived neurotrophic factor — and its receptor TrkB. BDNF is one of the main proteins involved in neuronal survival and synaptic plasticity, and preclinical work reports changes in BDNF expression following Semax administration in animal models.

Alongside that, the Russian literature includes work in ischaemic and hypoxic models, plus studies looking at attention and memory endpoints in animals. Much of this research is published in Russian-language journals and has not been replicated in large Western trials, which is an important limitation to state plainly.

None of this constitutes evidence of a human outcome, and Semax is not for human use.

These three are constantly confused because they came out of the same research programme and are sold alongside each other. They are not variants of one another.

• Semax — ACTH(4-10) derived. Studied around BDNF expression, neuroprotection and cognitive endpoints. Largest dataset of the three.
• Selank — tuftsin derived. Studied around GABAergic signalling and anxiolytic endpoints. Different parent molecule entirely.
• Adamax — Semax backbone with an adamantane modification. Very little independent published research; discussed largely by association.

Read the Adamax UK guide for the full breakdown of how the adamantane modification changes the molecule.

Most of the published Semax work uses an intranasal route, on the basis that a small stable peptide delivered nasally avoids first-pass metabolism. That is why Semax is commonly prepared as a nasal solution in research settings rather than as an injectable.

The reconstitution step is identical for either preparation — the difference is only in what the solution is transferred into afterwards. We also supply pre-filled nasal spray formats on suitable products; see the nasal spray peptides page.

Semax is supplied as a lyophilised powder in a 10mg vial. It is light-sensitive, so storage away from direct light matters more than with most peptides.

• Wipe the stopper with an alcohol swab and allow it to dry.
• Add bacteriostatic water slowly down the inside wall of the vial.
• Swirl gently until fully dissolved and clear — never shake.
• Label the vial with concentration and reconstitution date.
• Store at 2–8°C, protected from light, and use within 28 days.

A 10mg vial reconstituted with 2ml of bacteriostatic water gives 5mg/ml. For any other combination, use the free peptide calculator rather than a generic chart.

Semax is legal to buy and possess in the UK for laboratory research purposes. It is not a licensed medicine here, is not prescribed on the NHS, and is supplied strictly for in vitro research use only.

Every batch is independently HPLC and mass-spec tested. The batch number printed on the vial matches a published document on our Certificates of Analysis page, so purity can be verified before the vial is opened.

• UK-held stock — same working day dispatch on orders before 2pm, Mon–Fri.
• Royal Mail Tracked 24 with photo confirmation on every parcel.
• Independent HPLC and mass-spec testing with a batch-matched Certificate of Analysis.
• Discreet plain packaging and normal UK card checkout — no crypto required.
• Free 4 needles + 4 alcohol swabs with every vial — opt in at checkout.

• Adamax UK research guide
• Selank UK guide
• PE-22-28 UK guide
• Peptide reconstitution guide
• All peptide guides