# Semax FAQ — Regulatory Status, Mechanism, Half-Life, Russian-Language Evidence > Answers to common questions about Semax: prescription status in the US and abroad, FDA and EMA evaluation, mechanism, dosing in the published literature, half-life, side effects, and why most clinical evidence is Russian-language. Regulatory, mechanism, and literature-quality questions that recur in the Semax record. Sourced to the cited research. ## SECTION 01 / REGULATORY STATUS ### Is Semax prescribed by doctors in the United States? No. Semax has no marketing authorization from the United States Food and Drug Administration. It cannot be lawfully prescribed by a US-licensed physician for filling at a standard US pharmacy, and it is not compounded for human use through US compounding pharmacies operating under current FDA guidance. In the United States, Semax is sold only as a research chemical for in-vitro laboratory use. ### Is Semax legal to buy and possess in the United States? Semax is not a controlled substance under the United States Controlled Substances Act. It is not scheduled by the DEA. Personal importation of small research quantities falls in a regulatory gray zone — the substance can be sold by US vendors as a research chemical, but it cannot be marketed for human consumption and provides no FDA-recognized therapeutic claim. Customs treatment of small personal-research quantities varies and is not consistent. Larger commercial shipments and any marketing for human use would expose the importer or seller to FDA enforcement action. ### What is the regulatory status of Semax in other jurisdictions? The Russian Federation approved Semax as a prescription medication and added it to the Russian List of Vital and Essential Drugs on 7 December 2011. Ukraine has registered Semax for similar neurological indications. The European Medicines Agency has not approved Semax, the United Kingdom's MHRA has not approved Semax, and Health Canada has not approved Semax. The compound is not currently listed on the World Anti-Doping Agency Prohibited List in publicly available revisions — competitive athletes should reverify against the most recent annual list, since the broad category of non-approved substances (`S0`) can include unlisted compounds at WADA's discretion. ### What is Semax approved for in Russia? In Russia, Semax 1% intranasal is approved as adjunctive therapy in the acute period of ischemic stroke. Semax 0.1% intranasal is approved for nootropic and cognitive indications, including minimal brain dysfunction in pediatric patients, and is used as an adjunct in glaucomatous optic neuropathy. Both formulations are intranasal drops dispensed by prescription. ## SECTION 02 / MECHANISM AND PHARMACOLOGY ### How does Semax work in the brain? Semax is a synthetic analog of the `ACTH(4-10)` fragment of adrenocorticotropic hormone. It appears to engage the melanocortin receptor family — `MC3R`, `MC4R`, and `MC5R` — with partial agonist or antagonist activity that the literature describes as not yet fully resolved [1][2]. The downstream effects are better characterized: upregulation of `BDNF` and `NGF` mRNA and protein in hippocampus, basal forebrain, and frontal cortex; modulation of dopaminergic and serotonergic neurotransmission; inhibition of enkephalin-degrading enzymes (`IC50` near 10 μM); copper chelation with reduction of copper-induced amyloid-beta aggregation in artificial-membrane models; and direct modulation of intracellular calcium dynamics in rat brain neurons [9][12][17]. ### What is the half-life of Semax? In rats, the intact Semax peptide has a plasma half-life of two to five minutes after intranasal administration [13]. The active metabolite `Pro-Gly-Pro` accumulates in brain tissue and is itself biologically active, extending functional effects (`BDNF` and `NGF` mRNA upregulation, enkephalinase inhibition) for twelve to twenty-four hours after a single dose. The parent peptide is short-lived in plasma; the metabolite is what carries the duration in the central nervous system. ### Why is most Semax clinical evidence published in Russian-language journals? Semax was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the 1980s and entered clinical use through Russian neurology programs led by Gusev, Skvortsova, and colleagues at the Russian State Medical University. The principal clinical publications — the 1997 acute ischemic stroke trial [3], the recovery-phase `BDNF` study [14], the Polunin glaucoma study [15], and several pharmacokinetic and behavioral studies — appear in *Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova*, *Vestnik Oftalmologii*, *Russian Journal of Bioorganic Chemistry*, and the *Bulletin of Experimental Biology and Medicine*. No large multi-center double-blind randomized controlled trial of Semax meeting current Western regulatory standards has been published in a major Western journal. ## SECTION 03 / DOSING IN THE LITERATURE ### What are common research dosing ranges for Semax? In rat preclinical studies, intranasal doses of 50 to 250 mcg/kg single-dose are typical [1][2], with intraperitoneal doses ranging from 60 nmol/kg in the chronic-stress depression model [10] to 100 mcg/kg in the ischemia models [4][5][6]. The Russian approved-label human doses include 12 mg/day intranasal for moderate acute ischemic stroke and 18 mg/day for severe acute stroke (5- to 10-day courses) [3], and 6,000 mcg/day (6 mg/day) intranasal in the post-stroke recovery phase across two ten-day courses [14]. These are research-context and Russian-approved-label values — they are not US prescribing recommendations because no US prescribing register exists for Semax. ### Can the Russian approved-label doses be filled at a US pharmacy? No. Russian approved labeling does not constitute FDA-approved labeling. A US pharmacy cannot dispense Semax against a US prescription because no FDA-recognized labeled product exists. US compounding pharmacies operating under current FDA guidance do not compound Semax for human use. Sites that describe a 'Semax prescription' in a US clinical context are not describing a lawful prescription in the US sense. ### What is the difference between Semax 0.1% and Semax 1%? The two Russian-approved formulations differ in concentration of the intranasal solution. Semax 0.1% is dosed for nootropic and cognitive indications including minimal brain dysfunction in pediatric patients and as an ophthalmologic adjunct [15]. Semax 1% is dosed for acute neurological indications including acute ischemic stroke, where the higher concentration allows delivery of 12 to 18 mg/day in the small intranasal volume tolerated in acute care [3]. ## SECTION 04 / SAFETY AND CONSIDERATIONS ### What are the documented side effects of Semax? The available adverse-event reporting is limited to the relatively short Russian trial durations and post-marketing surveillance in Russia. Mild headache and nasal irritation are the most commonly noted effects. Russian post-marketing observations have noted mild blood-glucose elevations in approximately 7.4% of diabetic patients during Semax use — relevant for patients with glycemic concerns. Long-term safety data is sparse; no large prospective Western safety study exists. ### Is Semax the same as Selank? No, but the two are often discussed together. Selank is a different Russian regulatory peptide — a `TKPRPGP` analog of tuftsin developed by the same Myasoedov group at the Institute of Molecular Genetics. The two peptides share a common research lineage and both inhibit enkephalin-degrading enzymes of human serum [9], but they have different sequences, different receptor profiles (Selank has a primarily anxiolytic and immunomodulatory research profile), and different approved indications in Russia. ### What does Pro-Gly-Pro do? `Pro-Gly-Pro` (`PGP`) is the C-terminal tripeptide of Semax. In vivo it is cleaved from the parent heptapeptide and is itself biologically active. `PGP` accumulates in brain tissue with a substantially longer functional residence time than the intact peptide and is responsible for much of Semax's prolonged duration of action [13]. When administered alone in rat ischemia models, `PGP` activates similar neurotrophin gene programs to the parent peptide, though with less spatial selectivity to injured tissue [5]. --- An indexed editorial digest of peer-reviewed Semax research — not a clinic, not a pharmacy, not a prescription.