Peptide profile

Semax: FDA Status, Research and Uses

By Living+. Updated October 28, 2026.

Key takeaway

Semax is a synthetic 7-amino-acid analog of an ACTH fragment. It is not FDA approved but is registered in Russia ^[1]. It is not on the 503A bulks list, and FDA staff proposed not listing it in July 2026 ^{[3, 4, 13]}. Since October 28, 2026, an HHS interim policy covers compounding it for nasal use under set conditions ^[13].

At a glance

Where it stands

Checked October 28, 2026

FDA approvedNoNo approved product
Pharmacy compounding (503A)HHS interim policyOn HHS's interim enforcement policy (Appendix A), released Oct 28, 2026. HHS does not intend to take action against a state-licensed pharmacy, federal facility or licensed physician compounding Semax free base for intranasal use, with a patient-specific prescription and the policy's other conditions (FDA-registered source with a certificate of analysis, single ingredient, adverse event reporting). It is not FDA approval and not a place on the 503A bulks list; HHS may revisit it if a safety or quality problem arises. The July 2026 advisory committee voted in favor of listing it, and FDA's final rule is still pending.
Outsourcing facilities (503B)Not nominatedNot on FDA's 503B categories list (updated March 21, 2025). FDA reports no outsourcing facility has reported compounding Semax since 2019.
WADA (sport)UnclearNot named on the 2026 or 2027 List. S0 covers only substances with no approval by any government health authority; FDA's 2026 review states that Semax is a registered drug in Russia, so status is unclear.

Same data as the Status Tracker. Checked against 10 sources

Key facts

Class: Synthetic analog of the ACTH(4-10) fragment (heptapeptide) ^[1]
Length: 7 amino acids (Met-Glu-His-Phe-Pro-Gly-Pro) ^[1]
Half-life: Not established in humans; broken down quickly in rat blood and brain tissue ^[1]
Route in studies: Intranasal in human studies ^[1]
First studied: 1984 (synthesis first reported) ^[1]

How it works

Semax is a lab-made peptide based on ACTH(4-10), a piece of the stress hormone ACTH. It lacks the hormone effects of full ACTH but keeps some of its effects on the nervous system. An added Pro-Gly-Pro tail is thought to protect it from being broken down by enzymes ^[1].

In rodent studies, Semax showed many effects at once. FDA's review lists nerve-protective and nerve-growth effects, blood-thinning effects, pain relief, and antidepressant-like and anti-anxiety-like effects, through mechanisms that are poorly understood ^[1]. FDA also flags that in mice Semax boosted amphetamine-driven dopamine release, a pattern seen with drugs of abuse ^[1].

In rats, only a tiny share of an IV dose reached the brain ^{[1, 10]}. A larger share reached the rat brain when it was given in the nose ^[1].

Human research is small. In 24 healthy volunteers, nasal Semax changed activity in a resting brain network on fMRI scans ^[9]. In stroke patients in rehabilitation, Semax was linked with higher blood levels of BDNF, a nerve growth protein ^[8]. FDA found no human data on how the body absorbs or clears Semax ^[1].

What the research shows

3 human trials2 animal studies

2018Human trial
Gusev et al. 2018 (ischemic stroke rehabilitation)
Studied for stroke recovery
110 patients after ischemic stroke Comparison of rehabilitation groups with and without Semax ^[8]
It was linked with higher blood BDNF levels and better Barthel index scores ^[8].
Read the study
2018Human trial
Lebedeva et al. 2018 (brain networks)
24 healthy volunteers (14 Semax, 10 placebo) Placebo-controlled resting state fMRI before and after one nasal dose ^[9]
Semax was linked with a larger frontal part of the default mode network than placebo ^[9].
Read the study
1996Human trial
Koroleva et al. 1996 (migraine and facial nerve pain)
37 adults with migraine, trigeminal neuralgia or dental plexalgia Single nasal dose, no control group, not blinded ^[1]
In the migraine group, 4 of 12 people reported their headache stopped. FDA judged the evidence insufficient ^{[1, 7]}.
Read the study
2020Animal study
Filippenkov et al. 2020 (brain ischemia)
Studied for brain injury after blocked blood flow
Rats Stroke model with gene expression analysis 24 hours later ^[11]
It lowered activity of inflammation genes and raised nerve signaling genes ^[11].
Read the study
1991Animal study
Potaman et al. 1991 (brain entry)
Rats IV dose of radiolabeled Semax ^{[1, 10]}
The highest brain level was about 0.005% of the dose given ^[1].
Read the study

Doses used in studies

All human studies FDA found gave Semax in the nose. Doses included a single dose of 0.5 mg/kg, 1 mg daily for 2 days, a single 0.25 mg dose, 1.2 mg, and a 1% solution three times a day for 10 days ^[1]. A stroke rehabilitation study used two 10-day courses of 6000 mcg per day with a 20-day break ^[8].

FDA found no safety data for injected Semax in humans ^[1].

Dosing is set by a licensed provider.

Side effects and safety

Semax is not FDA approved, so there is no FDA label or boxed warning. FDA concluded there is not enough clinical information to describe its safety. It found no human studies of how the body handles Semax and no safety data for injection ^[1].

Most human studies did not report side effects, and one reported none ^[1]. FDA raised a concern about bleeding because one report described blood-thinning effects, especially for people at risk of bleeding or taking blood thinners ^[1]. FDA also raised a concern about abuse potential based on its effects on dopamine in mice ^[1].

FDA says compounded Semax may carry a risk of immune reactions because of clumping and impurities, and that it has little safety information for the proposed routes ^[2].

April 22, 2026FDA: Certain bulk drug substances for use in compounding that may present significant safety risks

Legal and regulatory history

October 28, 2026
HHS issued an interim enforcement policy for certain peptides used in 503A compounding. Until a final rule decides whether Semax goes on the 503A bulks list, HHS does not intend to take action against state-licensed pharmacies, federal facilities or licensed physicians who compound it under the policy's conditions ^[13]. For Semax free base, the policy covers intranasal use ^[13]. Conditions include a single active ingredient, bulk substance from an FDA-registered facility with a certificate of analysis, reporting of serious adverse events to FDA and a patient-specific prescription ^[13]. The policy is not FDA approval and does not place Semax on the 503A bulks list ^[13]. HHS may revisit it if a safety signal or product quality issue arises ^[13]. A Federal Register notice of availability, which calls the policy a draft, publishes October 30, 2026 ^[14]. Source
July 24, 2026
FDA's Pharmacy Compounding Advisory Committee discussed Semax (free base) and Semax acetate for cerebral ischemia, migraine and trigeminal neuralgia. FDA proposed that neither be placed on the 503A bulks list ^{[3, 4]}. HHS's October 28, 2026 policy states the committee voted in favor of both forms ^[13]. Source
May 11, 2026
FDA staff completed their evaluation and concluded the criteria weigh against listing Semax for 503A compounding ^[1]. Source
April 22, 2026
FDA's safety risk page, updated this date, lists Semax among substances whose nominations were withdrawn. FDA is still evaluating it on its own ^{[1, 2]}. Source
April 16, 2026
FDA announced the July 2026 advisory committee meeting in the Federal Register, listing Semax for review ^[5]. Source
January 1, 2026
The WADA 2026 Prohibited List took effect. Semax is not named. Its S0 class covers substances with no approval by any government health authority. FDA's review states that Semax "is a registered drug in Russia," so its status is unclear ^{[1, 6, 12]}. Source

Common questions

Is Semax FDA approved?

No. FDA states Semax is not a component of an FDA-approved drug and has no USP or NF monograph ^[1].

Is Semax approved in Russia?

FDA's 2026 review states that Semax is a registered drug in Russia, available as 0.1% and 1% nasal drops ^[1].

Is Semax legal to compound in the US?

Semax is still not on the 503A bulks list and is not FDA approved, and FDA's final rule is pending ^{[1, 13]}. FDA staff proposed not to list it in July 2026 ^{[3, 4]}. Since October 28, 2026, an HHS interim policy says HHS does not intend to take action against state-licensed pharmacies, federal facilities or licensed physicians who compound Semax free base for intranasal use under set conditions ^[13]. The policy is not FDA approval, and HHS may revisit it ^[13].

What happened at the July 2026 FDA meeting on Semax?

FDA advisers discussed Semax on July 24, 2026, after FDA staff proposed against listing it ^{[3, 4]}. HHS's October 28, 2026 policy states the committee voted in favor ^[13]. FDA's final rule is still pending ^[13].

Is Semax banned by WADA?

Semax is not named on the 2026 List. The S0 class bans substances with no government approval for human use anywhere. FDA's review states that Semax is a registered drug in Russia, so its WADA status is unclear ^{[1, 6]}.

What are the side effects of Semax?

Most studies did not report side effects. FDA flags possible bleeding risk, possible abuse potential and immune reactions with compounded forms ^{[1, 2]}.

Was Semax studied for ADHD or as a nootropic?

FDA did not evaluate ADHD because it found no supporting literature. It reviewed the nootropic claim as part of cerebral ischemia and found insufficient evidence ^[1].

How was Semax given in studies?

Human studies FDA found used nasal drops or sprays. FDA found no human safety data for injection ^[1].

Key takeaway

At a glance

Key facts

How it works

What the research shows

Gusev et al. 2018 (ischemic stroke rehabilitation)

Lebedeva et al. 2018 (brain networks)

Koroleva et al. 1996 (migraine and facial nerve pain)

Filippenkov et al. 2020 (brain ischemia)

Potaman et al. 1991 (brain entry)

Doses used in studies

Side effects and safety

Legal and regulatory history

Common questions

Sources