Cognition, mood & sleepNasal spray

Semax

Also known as: ACTH (4–10) analogue

Semax is a synthetic peptide derived from a fragment of the hormone ACTH, studied for focus, cognition and protection of nerve cells (neuroprotection).

Physician-reviewedDr. Bushra Mir, Medical Director · DHA-licensedReviewed 10 July 2026

The molecule, up close

Class: Synthetic peptide (ACTH fragment analogue)
Origin: Developed in Russia from a fragment of ACTH
Chemistry: Heptapeptide, without the hormone's steroid-stimulating action
Typical format: Nasal spray
Regulatory status: Approved in some countries; under study elsewhere

This page is educational information, not medical advice or an offer of treatment. Peptides used clinically are prescription medicines; whether any is appropriate for you is a decision a physician makes after a diagnostic assessment.

What it is

Semax is a Russian-developed peptide based on a short fragment of ACTH — a hormone involved in the stress axis — but modified so that it doesn't stimulate the adrenal glands the way the full hormone does. It has been studied there in cognitive and neurological contexts.

Like Selank, it's a well-known "nootropic" peptide whose reputation runs ahead of the international evidence base.

What it's studied for

Interest centres on attention, cognitive performance and neuroprotective signalling — the maintenance and protection of nerve cells. It has been studied in stroke and cognitive-recovery contexts in its country of origin.

These are areas of active study. Cognitive symptoms warrant a proper clinical work-up, and Semax is researched in this space rather than established internationally.

The science

Research links Semax to brain-derived neurotrophic factor (BDNF) and other neurotrophic signalling involved in keeping nerve cells healthy, as well as to neurotransmitter systems.

The full mechanism isn't yet settled, and much of the work sits outside large, independent international trials.

Typical form

Nasal spray

Shown in the dispensing format most often used in research and clinical settings. Where any protocol is appropriate, the route, dose and schedule are a physician’s decision — not a fixed recipe.

Safety & considerations

Prescription-only and physician-supervised. Suitability and monitoring are assessed individually, and cognitive concerns deserve a proper clinical assessment first.

Product quality and clinical oversight matter for using any peptide responsibly outside its approved settings.

Status & oversight

Semax is approved and used in some countries; elsewhere it's still under study. Any clinical use is medically directed.

Common questions

Semax, in brief.

What is Semax used for?

It's studied for focus, cognition and neuroprotection. In some countries it's used clinically; elsewhere it's still under study — and cognitive symptoms deserve a clinical assessment before any peptide is considered.

Does Semax improve focus?

It's researched in that area, but the broader evidence is limited, so improvement can't be promised. Its effects vary, and any use is a supervised, individual decision.

Is Semax a stimulant?

No. It's a peptide studied for cognitive and neuroprotective signalling, not a stimulant drug, and it shouldn't be treated as one.

Peptides of this kind are prescription medicines. Whether any protocol is appropriate is decided the way the rest of the practice works — from data, after an assessment.

How our longevity assessment works Back to the peptide field guide

How this is written

Physician-reviewed and evidence-led. We describe what a compound is studied for and where the evidence stands — not what it will do for you — and we revise pages as the science changes. Reviewed by Dr. Bushra Mir, Medical Director · DHA-licensed.

References

Peer-reviewed references for this compound are added by the physician author before publication.