--- title: "Semax 10mg" url: "https://lotuspeptide.com/peptide/semax" canonical: "https://lotuspeptide.com/peptide/semax" type: "product" brand: "LotusPeptide" strength: "10 mg" currency: "USD" price_low: "35.00" price_high: "220.00" availability: "in stock" ships_from: "United States" handling_time_business_days: 1 returns: "not accepted" replacements_and_refunds: "damaged or lost items" intended_use: "Laboratory research use only" image: "https://lotuspeptide.com/order/api/media/products/29.webp?size=full&v=1" updated: "2026-10-05" order_url: "https://lotuspeptide.com/order/p/29" synonyms: "MEHFPGP, ACTH (4-7), Pro-Gly-Pro-, Met-Glu-His-Phe-Pro-Gly-Pro" cas: "80714-61-0" formula: "C37H51N9O10S" molecular_weight: "813.9 g/mol" sequence: "Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP)" pubchem: "9811102" written_by: "LotusPeptide research team" --- # Semax 10mg > Research grade. Lyophilised powder, 10mg per vial. ## Packs and prices - Availability: In stock - Order: https://lotuspeptide.com/order/p/29 | Pack | Price | Per vial | |---|---|---| | Single Vial | $35 | $35 | | 5-Pack (5 vials) | $140 | $28 | | 10-Pack (10 vials) | $220 | $22 | ## At a glance - Strength: 10 mg - Also known as: MEHFPGP, ACTH (4-7), Pro-Gly-Pro-, Met-Glu-His-Phe-Pro-Gly-Pro - CAS number: 80714-61-0 - Molecular formula: C37H51N9O10S - Molecular weight: 813.9 g/mol - Sequence: Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP) - PubChem CID: 9811102 - Availability: In stock - Ships from: United States - Intended use: Laboratory research use only - Page updated: 2026-10-05 Written by LotusPeptide research team. Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro, made by attaching Pro-Gly-Pro to the 4-7 stretch of adrenocorticotropic hormone (ACTH). Russian researchers developed it, Russia registers it as a medicine, and the FDA has not approved it. ## What Semax is Semax keeps the Met-Glu-His-Phe segment of ACTH and follows it with the tripeptide Pro-Gly-Pro [1]. Biochemical papers call it a synthetic analog of the ACTH 4-10 fragment [2]; the first four residues match that fragment and the last three do not. According to FDA's 2026 briefing document, citing a 2013 paper from the Russian group that developed it, Semax lacks the corticotropic and melanotropic hormone activity of full-length ACTH. According to FDA's briefing, the C-terminal Pro-Gly-Pro sequence is thought to protect the molecule against peptidase cleavage. A 1991 study in rat serum found Semax more resistant than ACTH 4-10 to the enzymes involved other than an N-terminal aminopeptidase [2]. Other names include MEHFPGP and ACTH (4-7), Pro-Gly-Pro-. ## Chemical identity and look-alike variants PubChem CID 9811102 records Semax as the free base: C37H51N9O10S, 813.9 g/mol, CAS 80714-61-0. FDA's briefing quotes 813.93 g/mol and assigns UNII I5FAL2585H. Its one sulfur atom sits in the N-terminal methionine side chain. FDA evaluated semax free base and semax acetate as two separate substances. It found that a certificate submitted with one nomination named one form in its title while giving the CAS number and formula of the other. Names close to Semax also cover modified peptides. Acetylating the N-terminus produces Ac-Semax, which a 2016 study found forms a different copper(II) complex and behaves differently from Semax in a copper toxicity assay in neuroblastoma cells [1]. Anything sold as N-acetyl Semax or N-acetyl Semax amidate is a different chemical entity and has to be identified on its own terms. ## Regulatory status No FDA approval exists for Semax, and a search of the openFDA Drugs@FDA dataset finds nothing under its name. FDA's 2026 briefing document states that no USP or National Formulary monograph covers it and that it is not part of any FDA-approved drug. The European, Japanese and International Pharmacopoeias have no monograph either. The same document identifies Semax as a registered drug in Russia. On FDA's significant-safety-risk compounding page, semax (heptapeptide) appears in the table of category 2 nominations that were later withdrawn. Semax free base and semax acetate were on the agenda of FDA's Pharmacy Compounding Advisory Committee meeting of July 24, 2026, as candidates for the 503A bulks list. As of October 2026, FDA had not published a decision. Russian registration does not alter the US position, and Semax from this store is sold for laboratory research, not as an approved medicine. ## Published research Russian groups produced most Semax studies, publishing in both Russian- and English-language journals. Work on its metabolism came early: in rat blood and serum, a bestatin-sensitive aminopeptidase removed the N-terminal Met and then Glu [2]. A 2004 binding study used Semax labeled evenly with tritium and plasma membranes from the basal nuclei of rat forebrain. It reported time-dependent, specific, reversible and calcium-dependent binding, with a dissociation constant of about 2.4 nM [3]. In the same membrane system, dipeptidyl aminopeptidases cut Semax stepwise to HFPGP and then PGP, and its half-life exceeded one hour [3]. A radiolabel kinetics study in rats found the peptide degraded quickly, with Pro-Gly-Pro the dominant labeled species [4]. Data in people are sparse. Resting-state fMRI compared Semax with placebo in 24 healthy volunteers [5], and with Selank and placebo in 52 [6]. Small clinical studies in patients exist, mostly in Russian-language journals, and are not summarized here. ## What is not known FDA's 2026 review listed the main gaps. It found no human pharmacokinetic data for any route of administration. It judged neither the free base nor the acetate well characterized, pointing to inconsistent naming and to missing public data on impurities, aggregates and endotoxin. Its search of the FAERS adverse event database through December 2025 turned up one report. Whether Semax fragments act in their own right is also open. The rat serum study proposed that N-terminally shortened intermediates could add to the effects credited to intact Semax [2], and the membrane work shows Semax being cleaved stepwise to HFPGP and then PGP [3]. ## Quality testing and storage Three checks are specific to Semax. First, methionine at position 1 oxidizes easily, so a certificate should look for the sulfoxide, which weighs 16 Da more than the parent. Second, the des-Met and des-Met-Glu peptides made by aminopeptidase cleavage [2], and the HFPGP fragment [3], should resolve from the main peak in the HPLC purity method. The 2004 study separated such fragments by HPLC with UV detection at 220 and 254 nm [3]. Third, the salt form needs stating, because FDA found free base and acetate mixed up in submitted paperwork. Mass spectrometry confirms identity: from PubChem's monoisotopic mass of 813.348 Da, the protonated molecule falls near m/z 814.36. Net peptide content, appearance, lot and analysis date round out the record. On storage, FDA's briefing cites a report that lyophilized semax free base kept in a tightly closed container at -20 °C remained stable; otherwise, store as stated on the certificate of analysis and product label. The purity of any given lot is a matter for its own certificate. ## Questions ### Why is Semax called an ACTH 4-10 analog if it contains only ACTH 4-7? It retains the first four residues of ACTH 4-10 (Met-Glu-His-Phe) and swaps the last three for Pro-Gly-Pro. It was designed as a modified form of that fragment, which is why papers describe it as an ACTH 4-10 analog. ### Is N-acetyl Semax the same compound as Semax? No. N-terminal acetylation yields a different molecule with its own formula and mass, and published work shows it binds copper(II) differently. Material sold as N-acetyl Semax or N-acetyl Semax amidate needs separate identity confirmation by mass spectrometry. ### What is the FDA status of Semax? FDA has not approved it. Semax was on the agenda of FDA's Pharmacy Compounding Advisory Committee meeting of July 24, 2026, as a possible bulk substance for compounding. As of October 2026, FDA had not published a decision. ## References 1. [Magrì A, Tabbì G, Giuffrida A, et al. Influence of the N-terminus acetylation of Semax, a synthetic analog of ACTH(4-10), on copper(II) and zinc(II) coordination and biological properties. J Inorg Biochem. 2016.](https://pubmed.ncbi.nlm.nih.gov/27586814/) 2. [Potaman VN, Alfeeva LY, Kamensky AA, et al. N-terminal degradation of ACTH(4-10) and its synthetic analog semax by the rat blood enzymes. Biochem Biophys Res Commun. 1991.](https://pubmed.ncbi.nlm.nih.gov/1851003/) 3. [Dolotov OV, Zolotarev IuA, Dorokhova EM, et al. [The binding of Semax, ACTH 4-10 heptapeptide, to plasma membranes of the rat forebrain basal nuclei and its biodegradation]. Bioorg Khim. 2004.](https://pubmed.ncbi.nlm.nih.gov/15344653/) 4. [Shevchenko KV, Nagaev IIu, Alfeeva LIu, et al. [Kinetics of Semax penetration into the brain and blood of rats after its intranasal administration]. Bioorg Khim. 2006.](https://pubmed.ncbi.nlm.nih.gov/16523722/) 5. [Lebedeva IS, Panikratova YR, Sokolov OY, et al. Effects of Semax on the Default Mode Network of the Brain. Bull Exp Biol Med. 2018.](https://pubmed.ncbi.nlm.nih.gov/30225715/) 6. [Panikratova YR, Lebedeva IS, Sokolov OY, et al. Functional Connectomic Approach to Studying Selank and Semax Effects. Dokl Biol Sci. 2020.](https://pubmed.ncbi.nlm.nih.gov/32342318/) _This page summarises published laboratory research and cites its sources. It is not medical advice and makes no claim that the compound treats, cures or prevents any condition. LotusPeptide sells it for laboratory research use only._ ## Shipping and returns - Orders are processed and shipped within 1 business day. - Returns are not accepted. - Replacements and refunds are offered on damaged or lost items. ## Related products - [BPC-157+TB500 (Blend) 10mg](https://lotuspeptide.com/peptide/bpc-157-tb500-blend.md): from $35 - [GHK-Cu](https://lotuspeptide.com/peptide/ghk-cu.md): from $20 - [Retatrutide](https://lotuspeptide.com/peptide/retatrutide.md): from $25 --- For laboratory research use only. Not for human or veterinary use. Prices are in US dollars and can change without notice.