Not approved in the U.S.Semax has no FDA approval.[1] The FDA found "insufficient evidence to support the effectiveness" of semax and raised concerns about bleeding and abuse potential.[4] This page does arithmetic and reports the record; it does not suggest amounts.
What is the semax peptide?
Semax is the heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro, which the FDA describes as a "synthetic heptapeptide analog of the ACTH 4-10 fragment".[17][4]
- Sequence
- MEHFPGP: ACTH(4–7) followed by Pro-Gly-Pro[17]
- Formula and weight
- C37H51N9O10S, 813.9 g/mol; acetate salt 874.0 g/mol
- Outside the U.S.
- FDA: "Semax is a registered drug in Russia and is available as 0.1% and 1% nasal drops." We could not open the Russian register to confirm it ourselves.[4]
Regulatory status in November 2026
The FDA recommended against compounding semax; HHS's 2026 policy nonetheless covers compounded intranasal semax.
| Date | What happened |
|---|---|
| Sept 29, 2023 | Placed in 503A Category 2[3] |
| Apr 22, 2026 | Removed after the nominations were withdrawn; FDA's safety table says it "may pose risk for immunogenicity"[2] |
| July 24, 2026[4][5] | FDA proposes not adding semax to the 503A bulks list, after reviewing it for cerebral ischemia, migraine and trigeminal neuralgia |
| Oct 30, 2026[6] | HHS policy covers semax free base for intranasal use only |
- Bleeding. FDA: a reference on "possible anti-thrombotic properties of semax ... raises concern about the risk of bleeding", especially with other drugs that increase bleeding risk.[4]
- Abuse potential. FDA notes that in mice semax "potentiated amphetamine-induced dopamine release", a response typical of drugs of abuse.[4]
- A reported harm. The FDA's adverse event database had one report: eye pain and burning, with hospitalization, after "Semax 0.1% nasal drops purchased online".[4]
- Enforcement. FDA warning letters in 2020 and 2021 named semax among substances not eligible for compounding.[7][8]
- Sport: not named on the WADA 2026 list; from 2027 the list names "peptides" in general under S0.[15][16]
Semax dosage in published studies
The human studies are small, mostly Russian-language and nearly all intranasal; the FDA found no human data for injections and no pharmacokinetic data by any route.[4]
| Study | People | Amount and route studied | Reported |
|---|---|---|---|
| Gusev 1997[9] | 30 patients with acute ischemic stroke vs 80 on standard therapy | 12–18 mg a day, 5- and 10-day courses | Faster recovery of neurological deficits reported; no adverse event data in abstract |
| Gusev 2018[10] | 110 patients after ischemic stroke | 6,000 mcg a day, two 10-day courses | Higher BDNF and better daily-living scores reported |
| Serdiuk 2007[11] | 27 patients with motor neuron disease, open-label | 1% solution in the nose, 12 mg a day, two 10-day courses | No effect on denervation or clinical scales |
| Ivanikov 2002[12] | 32 adults with peptic ulcer, added to standard therapy | 1% solution, 2–4 drops per nostril 3 times a day for 10 days | Ulcer healing at day 14: 89.5% vs 30.8%; adverse events not discussed |
| Lebedeva 2018[13] | 24 healthy adults, placebo-controlled | Single intranasal dose | Changes on brain scans; adverse events not discussed |
| Panikratova 2020[14] | 52 healthy adults (semax, selank or placebo) | Single dose | Changes in amygdala connectivity |
No large, double-blind, placebo-controlled trial of semax in English was found. Amounts above are what researchers used under study conditions, not doses for anyone.
Semax nasal spray: what 0.1% and 1% mean
A percentage solution is grams per 100 mL, so 0.1% semax is 1 mg/mL and 1% is 10 mg/mL. At 10 mg/mL, 0.1 mL holds 1 mg, which is 1,229 nmol of semax.
| Strength | mg per mL | mcg per 0.01 mL | mcg per 0.05 mL |
|---|---|---|---|
| 0.1% | 1 | 10 | 50 |
| 1% | 10 | 100 | 500 |
Nose drops are not measured on a syringe, so units do not apply to them; the calculator above is only for powder vials. Its concentration chart:
| Vial + liquid | mg/mL | mcg per unit | nmol per unit | Units per 100 mcg |
|---|---|---|---|---|
| 1 mg + 1 mL | 1 | 10 | 12.29 | 10 |
| 1 mg + 2 mL | 0.5 | 5 | 6.14 | 20 |
| 10 mg + 1 mL | 10 | 100 | 122.87 | 1 |
| 10 mg + 2 mL | 5 | 50 | 61.43 | 2 |
Other peptide pages
The peptides most often looked up alongside this one. Each page gives that peptide's FDA status, compounding status and published human evidence, with sources; the status table has all 23 in one place.
- PT-141 (bremelanotide)FDA-approved Vyleesi: a prefilled 1.75 mg autoinjector. No mixing needed.
- SelankNot approved TP-7 heptapeptide. Never reviewed by the FDA committee.
- MT2 (melanotan II)Not approved Melanotan II. Never approved; FDA cites melanoma reports.
- DSIP (emideltide)Not approved Delta sleep-inducing peptide. Small IV studies, 1981–1998.
- BPC-157Not approved 15-amino-acid peptide. Human data: a few tiny, uncontrolled studies.
- TB-500Not approved A 7-amino-acid fragment of thymosin beta-4. No human trials of TB-500 itself.
Frequently asked questions
What is the semax dosage?
Is semax FDA-approved?
Can semax be injected?
How is semax different from selank?
Both are seven-amino-acid peptides ending in Pro-Gly-Pro, but semax is built on an ACTH fragment and is covered by the 2026 HHS policy for intranasal use, while selank was never reviewed by the FDA advisory committee and is not in that policy. See the selank page.
Sources
- openFDA Drugs@FDA searches for AOD-9604, KPV, epitalon, semax, selank, cagrilintide, melanotan and NAD (no application found)
- Certain bulk drug substances for use in compounding that may present significant safety risks
- Bulk drug substances nominated for use in compounding under section 503A (category lists)
- FDA briefing document: semax-related bulk drug substances
- Pharmacy Compounding Advisory Committee meeting, July 23–24, 2026
- Enforcement discretion policy regarding 503A compounding using certain peptide bulk drug substances (91 FR 68526)
- Warning letter: Tailor Made Compounding LLC
- Warning letter: Advanced Nutriceuticals LLC dba The Guyer Institute of Molecular Medicine
- Gusev EI et al. Semax in acute ischemic stroke (Zh Nevrol Psikhiatr 1997;97:26–34)
- Gusev EI et al. Semax, BDNF and recovery after ischemic stroke (Zh Nevrol Psikhiatr 2018;118:61–68)
- Serdiuk AV et al. Semax in motor neuron disease (Zh Nevrol Psikhiatr 2007;107:29–39)
- Ivanikov IO et al. Semax as add-on therapy for peptic ulcer (Bull Exp Biol Med 2002;134:73–4)
- Lebedeva IS et al. Single-dose semax and brain resting-state fMRI (Bull Exp Biol Med 2018;165:653–656)
- Panikratova YR et al. Semax, selank and amygdala connectivity (Dokl Biol Sci 2020;490:9–11)
- World Anti-Doping Code: Prohibited List 2026
- Athlete advisory: what's new on the 2027 WADA Prohibited List
- PubChem CID 9811102: semax