What Is Semax?

Semax is a synthetic heptapeptide built from the ACTH(4–7) fragment of adrenocorticotropic hormone, extended with a stabilising Pro-Gly-Pro tail. The design keeps the fragment's neuroactive character, removes the parent hormone's endocrine role, and survives handling that would destroy the native sequence.

What is Semax?

ACTH is best known as a stress-axis hormone, but its short internal fragments have neuroactive properties independent of cortisol signalling. Semax captures the 4–7 fragment and stabilises it — the same strategy its sibling Selank applies to tuftsin — the full Selank vs Semax comparison maps the differences. The result is a compact CNS-focused probe with decades of literature, largely from the Russian research tradition.

What researchers study it for

Semax appears in cognition, neuroprotection, and BDNF-pathway research. Its appeal is a melanocortin-derived sequence with no corticotropic activity: protocols get the neuro side of the ACTH story without the endocrine side. In cognition work it is often read alongside newer stability-engineered designs like DIHEXA, which attack the same durability problem by different means.

Working with research-grade Semax

REPRIME supplies Semax as a lyophilized 15 mg vial, HPLC-verified per batch with a public COA and first-scan verification code. See the Semax product page for the current batch. Research use only.

Frequently asked questions

What is Semax made from?

The ACTH(4–7) fragment of adrenocorticotropic hormone, extended with a Pro-Gly-Pro tail that stabilises it against enzymatic degradation.

Does Semax act like ACTH?

No — Semax carries the fragment's neuroactive character without ACTH's corticotropic (stress-hormone) activity, which is precisely why researchers use it.

How is research-grade Semax supplied?

As a lyophilized 15 mg vial with batch HPLC verification, a public COA, and a verification code — see the product page.