Semax

ACTH(4-10) analog · B-tier (Dr. Alex Tatem) · Limited evidence

A nasal-spray peptide studied in Russia for stroke recovery and cognition. It’s very safe, but the data is noisy.

Dr. Tatem’s take

B-tier. The data is noisy and mostly Russian, but it’s very safe. On Diary of a CEO he noted it’s used intranasally and was studied after traumatic brain injury and stroke.

In Dr. Tatem’s tier list

• A seven-amino-acid peptide thought to help cognition and neuroprotection, particularly in stroke patients.
• Studied almost exclusively by Russian researchers — that doesn’t mean it doesn’t work, but the data “is a little noisy.”
• It tends to be “exceedingly safe,” and for people using it purely as a cognitive boost, results run about 50/50 — better than many compounds.
• Verdict: rises above the so-so C-tier compounds to a solid B tier.

History & background

Semax was developed in the 1980s at the Institute of Molecular Genetics of the Russian Academy of Sciences (Moscow) as a stabilized fragment of ACTH(4-10) — the part of the stress hormone ACTH that affects the brain but not the adrenal glands. It is approved in Russia for stroke and other neurological uses, given as nasal drops.

Western trials are lacking. In July 2026 FDA advisers voted 8–5–1 to recommend it for compounding (cerebral ischemia, migraine, trigeminal neuralgia); the vote is non-binding.

Benefits

• Associated with higher BDNF and better function scores in stroke rehabilitation.
• Proposed focus and neuroprotection benefits.

Risks

• Few reported; data is sparse.

Dosing protocols (informational, labeled by evidence)

• Clinical trial / label: Russian label 0.1% (nootropic) — 200–600 mcg per dose (2–6 drops per nostril), Intranasal, 2–3x daily, 10–14 days, repeat after 2–4 wk
• Clinical trial / label: Russian label 1% (stroke) — 3–6 mg per dose, Intranasal, 2–4x daily, Acute course

Status: Not approved in the US. FDA advisers voted 8–5–1 in July 2026 to allow compounding (stroke-related uses, migraine). Rulemaking is pending.

Grade and commentary: Dr. Alex Tatem. Watch: Truth About Popular Peptides Tier List (What Works, What’s Overhyped) | Pt. 3, The “Limitless” Peptide Actually Exists…, Peptide Expert: What Do Peptides Actually Do? (EXPLAINED) - Dr Alex Tatem. Subscribe: @DrAlexTatem.