Compounds / Semax
Semax
Also known as: Semax; Met-Glu-His-Phe-Pro-Gly-Pro; MEHFPGP; ACTH(4-10) analog; Semax acetate; CAS 80714-61-0
Primary research focus: Cognition and neuroprotection research (ACTH(4-10) analog); approved in Russia for stroke and cognitive indications
Last updated July 2026 · Reviewed against FDA labeling and published research.
What is Semax?
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the 1980s. It is an analog of the ACTH(4-10) fragment with a C-terminal Pro-Gly-Pro tail added for metabolic stability, and it retains the neurotropic activity of ACTH without its hormonal (corticotropic) effects. It has been an approved prescription pharmaceutical in Russia for decades, used for ischemic stroke, encephalopathy, and optic nerve atrophy. It has no FDA approval, and it is one of the peptides scheduled for FDA advisory committee review on July 24, 2026.
Semax is derived from ACTH(4-10) but lacks the sequence needed to stimulate cortisol release, so it retains neurotropic activity without hormonal effects. Its most cited mechanism is a rapid and sustained increase in brain-derived neurotrophic factor (BDNF) and its receptor TrkB, particularly in the hippocampus. Reported additional actions include modulation of the dopaminergic and serotonergic systems, inhibition of enkephalin-degrading enzymes (extending endogenous enkephalin activity), antioxidant and anti-inflammatory effects, and modulation of gene expression in neurons. The Pro-Gly-Pro tail resists enzymatic degradation and enables intranasal delivery with brain uptake. The mechanistic rationale for neuroprotection is multilayered and under active investigation; it does not establish efficacy in any specific human disease outside its Russian approvals.
How it’s supplied
Not FDA-approved or commercially available in the US. In Russia and Ukraine it is a registered prescription medicine, most commonly an intranasal solution (typically 0.1 percent or 1 percent). Elsewhere it is sold as a research-grade lyophilized peptide or nasal solution; such products are not FDA-reviewed for potency or sterility, and sale as a research chemical does not constitute authorization for human use.
Dosage Chart
Units shown are for a U-100 insulin syringe (100 units = 1 mL), calculated from the vial size and BAC water you select. Always confirm against your prescription and your syringe markings.
| Phase | Dose | Frequency | Notes |
|---|---|---|---|
| Week 1 | 100mcg | 1-3x Daily | — |
| Week 2 | 250mcg | 1-3x Daily | — |
| Week 3 | 500mcg | 1-3x Daily | — |
- Rotate injection sites to reduce irritation and lipohypertrophy
- Not for use during pregnancy or breastfeeding
- Do not exceed the recommended dose to try to speed results
Potential Benefits and Side Effects
Effects reported in published research. Not a promise of results, and not medical advice.
- Reported in Russian clinical use and research; not established in Western randomized controlled trials.
- Approved in Russia and Ukraine for ischemic stroke, encephalopathy, and optic nerve atrophy.
- Rapid and sustained increases in BDNF and TrkB expression in the hippocampus in preclinical models.
- Reported neuroprotective effects in cerebral ischemia and post-traumatic cognitive impairment.
- Reported improvements in attention and memory under cognitive load.
- Retains ACTH-derived neurotropic activity without hormonal (cortisol) effects.
- Reported adverse effects in Russian clinical use are generally mild and infrequent.
- Nasal irritation with intranasal administration.
- Reported potential to raise blood glucose, relevant in diabetes.
- The Western safety database is essentially absent, so uncommon and long-term effects are not characterized.
- Research-grade material carries identity and purity risks.
Warnings and contraindications
Important safety information. This is not exhaustive — read the full prescribing information and consult your prescriber or pharmacist.
- No FDA-approved labeling exists; the following reflect the compound's status and the limits of its evidence, not a US label.
- Semax is not FDA-approved; its Russian registration has no legal effect in the US, and the FDA has never reviewed it for safety or efficacy in any indication.
- The clinical evidence base is almost entirely Russian-language and has not been replicated in Western randomized controlled trials.
- Semax may raise blood glucose levels; caution is advised in people with diabetes.
- There is insufficient human research to evaluate fetal or infant safety; pregnancy and lactation are listed as contraindications in available safety summaries.
- Its US compounding status is in transition: it was removed from Category 2 on April 15, 2026, but removal is not the same as being added to the 503A bulks list, and the Pharmacy Compounding Advisory Committee review is scheduled for July 24, 2026.
- Research-grade material varies in identity and purity.
- Not established as a US drug; no FDA labeling. Based on available safety summaries, precautionary considerations include pregnancy and lactation, known hypersensitivity, and caution in diabetes given reported effects on blood glucose.
Reconstitution Steps
How to prepare the lyophilized vial. Confirm specifics with your pharmacist or prescriber.
- Confirm the amount of peptide in the vial and the volume of diluent you intend to use before starting.
- Wash your hands and gather supplies: the lyophilized vial, the diluent (typically bacteriostatic water), an alcohol swab, and a sterile syringe.
- Let the vial and diluent reach room temperature if they were refrigerated or frozen.
- Wipe the rubber stopper of both the peptide vial and the diluent vial with a fresh alcohol swab and let them air dry.
- Draw the intended diluent volume into the syringe.
- Insert the needle into the vial and slowly release the diluent down the inside wall rather than directly onto the powder, to avoid foaming.
- Do not shake. Gently swirl or roll the vial until fully dissolved.
- Inspect the solution: it should be clear and colorless with no visible particles. Do not use if cloudy or containing particles.
- Note the resulting concentration (amount divided by diluent volume) so it matches the reconstitution calculator on this page.
- Label the vial with the reconstitution date and store as directed under reconstituted storage.
US regulatory status
Classifications are public record but can change. For reference only, not legal advice.
Development: Semax was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the 1980s and has been an approved pharmaceutical in Russia for decades (with reported registration as a prescription medicine since 2011 for its current indications), carrying approvals in Russia and Ukraine for ischemic stroke, encephalopathy, and optic nerve atrophy. It is on Russia's official Vidal register. The FDA has never reviewed it. Regulatory movement in 2026 has been substantial: Semax was among the peptides placed in Category 2 in September 2023, and the FDA's revised 503A document published April 15, 2026 removed Semax (both free base and acetate) from Category 2 and scheduled it for Pharmacy Compounding Advisory Committee review on July 24, 2026, where the nominated uses under discussion are cerebral ischemia and trigeminal neuralgia. An important nuance: the April removal was tied to the original nominators withdrawing their nominations; it lifted do-not-compound status but did not add these peptides to the 503A bulks list, leaving them in a gray zone until the PCAC recommends inclusion and the FDA acts. The public docket is FDA-2025-N-6895.
Notes: Semax is not FDA-approved; its approval in Russia and Ukraine has no legal effect in the US. Its compounding status is in transition. It was placed in FDA Category 2 in September 2023; the FDA's revised 503A document of April 15, 2026 removed Semax (free base and acetate) from Category 2 and scheduled it for Pharmacy Compounding Advisory Committee review on July 24, 2026 (docket FDA-2025-N-6895), with cerebral ischemia and trigeminal neuralgia as the nominated uses. Critically, removal from Category 2 is not the same as being added to the 503A bulks list: compounds removed but not yet listed sit in a regulatory gray zone until the PCAC recommends inclusion and the FDA acts. Verify against the current FDA list. It is not a controlled substance. (Status current as of mid-2026.)
International status
Pharmacokinetics
Storage and handling
Important Notes
Practical considerations for consistency and safety.
- Semax has been an approved prescription medicine in Russia for decades (stroke, encephalopathy, optic nerve atrophy) but has never been reviewed by the FDA.
- Its compounding status is in active transition: removed from Category 2 on April 15, 2026 and scheduled for PCAC review on July 24, 2026 for cerebral ischemia and trigeminal neuralgia.
- Removal from Category 2 is NOT the same as being added to the 503A bulks list; the compound sits in a gray zone until the PCAC recommends and the FDA acts.
- It may raise blood glucose; caution in diabetes.
- It shares only a Pro-Gly-Pro stabilizing tail with Selank; the two are otherwise unrelated. Its acetylated amidated derivative is Adamax.
Lifestyle Factors
- Most commonly studied as an intranasal solution in short courses.
- Often paired with Selank in Russian practice and community protocols; that combination is not a clinically validated protocol.
References
Related compounds
Important disclaimer
This page is an educational reference, not medical advice, a diagnosis, or a treatment recommendation, and not a substitute for your prescriber or pharmacist. Approval and regulatory status varies by compound and can change. Always confirm against current prescribing information and consult a qualified healthcare professional before making any decision about a medication.