WhatPeptide

Semax

A synthetic ACTH fragment analog studied in Russia for neurocognitive and cerebrovascular contexts. Placed on FDA Category 2 list (September 29, 2023) as 'Semax (heptapeptide).'

Moderate evidence FDA Category 2 Nootropic

Written by WhatPeptide Editorial Team · Last updated 2026-03-17

FDA Category 2 — compounding availability may be limited.

Half-life

Short (minutes to ~1 hour), with downstream effects longer

Dosage range

300-900 mcg/day intranasal divided doses (published research context)

Administration

Intranasal

Research level

Moderate

How Semax works

Semax appears to influence BDNF-related neurotrophic pathways, monoaminergic tone, and stress-response peptides in preclinical studies. Intranasal delivery targets central exposure while minimizing systemic peptide degradation. Most published trials are regional and heterogeneous in design quality.

Also known as: ACTH(4-10) analog, Heptapeptide Semax

Research relevance

Cognition & Focus
Strong research relevance 90
Immune Support
Some relevance 40
Sleep & Relaxation
Some relevance 30
Anti-Aging & Longevity
Some relevance 25
Recovery & Healing
Some relevance 20

Side effects & safety

Nasal irritation Headache Anxiety in sensitive users

Contraindications

Pregnancy
Severe uncontrolled psychiatric disorders

Consult a healthcare provider before use if any of these apply to you.

Key studies

FAQ

What is Semax? +
A synthetic ACTH fragment analog studied in Russia for neurocognitive and cerebrovascular contexts. Placed on FDA Category 2 list (September 29, 2023) as 'Semax (heptapeptide).' Its mechanism of action is supported by moderate clinical and preclinical evidence.
What is Semax researched for? +
Semax has the strongest research relevance for Cognition & Focus, Immune Support, Sleep & Relaxation. Evidence is supported by moderate clinical and preclinical evidence.
What are the side effects of Semax? +
Reported side effects include Nasal irritation, Headache, Anxiety in sensitive users. Key contraindications: Pregnancy; Severe uncontrolled psychiatric disorders.
Is Semax FDA approved? +
Semax is classified as FDA Category 2, meaning compounding availability may be limited.
How is Semax administered? +
Semax is typically administered via nasal route. Researched dosage range: 300-900 mcg/day intranasal divided doses (published research context). Half-life: Short (minutes to ~1 hour), with downstream effects longer.

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