Nootropic/neuroprotective heptapeptide (ACTH 4-10 analogue)

Semax

A Russian-developed ACTH-fragment peptide studied for neuroprotection and cognition.

Mostly preclinical

At a glance

Sequence
Met-Glu-His-Phe-Pro-Gly-Pro (ACTH(4-10) analogue)
Molecular weight
CAS
Class
Nootropic/neuroprotective heptapeptide (ACTH 4-10 analogue)
Aliases

Overview

Derived from ACTH(4-10) but without steroidogenic activity.

Approved in Russia for stroke and cognitive disorders; Western evidence is largely preclinical but notably active in 2025.

Mechanism

Upregulates BDNF and NGF, modulates dopaminergic/serotonergic signalling and reduces oxidative stress.

Research

What the studies show

Semax in an Alzheimer's transgenic-mouse model

Ilchibaeva TV, et al. · Acta Naturae · 2025 · Preclinical

In an Alzheimer's transgenic-mouse model, Semax and a derivative improved cognition and reduced cortical/hippocampal amyloid inclusions.

Semax targets Oprm1 after spinal-cord injury

Liu R, et al. · British Journal of Pharmacology · 2025 · Preclinical

Identified a novel mechanism — Semax targets the µ-opioid receptor gene Oprm1 to aid recovery after spinal-cord injury in mice.

Semax and amyloid-β/Cu(II) oxidative stress

Tomasello, et al. · Bioinorganic Chemistry and Applications · 2025 · Preclinical

Semax cut reactive oxygen species from the amyloid-β/Cu(II) complex and protected neuroblastoma cells from copper-catalysed oxidative stress.

Qualitative review in Parkinson's models

UTRGV · Review · 2025 · Review

In Parkinson's models Semax reliably reduced anxiety but showed inconsistent motor/dopamine effects; no human PD trials exist.

Neuroprotection in MPTP-induced lesions

Levitskaya NG, et al. · Neurosci Behav Physiol · — · Foundational

Showed neuroprotective effects in MPTP-induced dopaminergic lesions.

Evidence summary

One of the most actively researched nootropic peptides today, with a surge of 2025 preclinical work in cognition and neuroprotection, built on decades of approved clinical use abroad. A compelling and fast-moving area of neuroscience research.