> ## Site index > Full index of Peptides.build at https://peptides.build/llms.txt. Use it to discover every page. # Semax vs Selank: What Is the Difference? Semax and Selank compared: origin, sequence, the pathways studied, the evidence behind each, and why one US protocol prescribes them together. URL: https://peptides.build/learn/semax-vs-selank/ Comparison · Cognitive # Semax vs Selank: what is the difference? Published October 12, 2026 · Educational, not medical advice ## Short answer Semax and Selank are both synthetic seven-amino-acid peptides developed at the Institute of Molecular Genetics in Moscow, but they come from different natural peptides: Semax from a fragment of the hormone ACTH, Selank from the immune peptide tuftsin. Both are registered medicines in Russia, neither is FDA-approved for any use, and in the US they are prescribed together only as a compounded medication; compounded medications are not FDA-approved. - [What are Semax and Selank?](#what-they-are) - [How do Semax and Selank differ?](#differences) - [What does the research cover for each?](#research) - [How are Semax and Selank prescribed?](#prescribed) - [Are Semax and Selank FDA-approved or allowed in sport?](#status) - [FAQ](#faq) - [References](#references)
Semax vs Selank quick facts
SemaxSynthetic heptapeptide, analog of the ACTH(4-7) fragment with a Pro-Gly-Pro tail
SelankSynthetic heptapeptide, analog of tuftsin with a Pro-Gly-Pro tail
Key differenceDifferent parent peptides and different pathways studied: neurotrophic signaling (Semax) versus GABAergic gene expression (Selank)
Shared originInstitute of Molecular Genetics, Moscow; both registered medicines in Russia
Evidence to dateRussian clinical studies, mostly not randomized, plus animal and cell work; no Western randomized trials for either
Form in this catalogOne protocol, two vials, subcutaneous injection, supplied already reconstituted
Regulatory statusCompounded medication; neither is FDA-approved for any use
Anti-dopingNeither is named on the WADA Prohibited List; the S0 non-approved substances category can apply
Evidence snapshot**What kind of research is cited for Semax vs Selank?**2 cited sources: 1 human clinical trial, 1 animal or lab study. Counts describe study type, not strength of result. Sources cited for Semax vs Selank, by study type | Study type | Sources | | --- | --- | | Human clinical trials | 1 | | Other human studies | 0 | | Animal and lab studies | 1 | | Review articles | 0 | ## What are Semax and Selank? Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro, whose first four residues are positions 4 to 7 of adrenocorticotropic hormone, ACTH, with a Pro-Gly-Pro tail added. Selank is a synthetic heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, whose first four residues are tuftsin, a natural immune peptide, with the same Pro-Gly-Pro tail. Both were developed at the Institute of Molecular Genetics in Moscow and both are registered medicines in Russia, which is why they are so often mentioned in the same breath. Semax and Selank are not two versions of one drug. The shared tail and the shared institute make them look like siblings, but the parent molecules come from different systems, a pituitary hormone on one side and an immune peptide on the other, and the research on each has followed its parent rather than the pairing. ## How do Semax and Selank differ? Semax and Selank differ in origin, sequence, the pathway each has been studied for, and the kind of evidence behind each. The table sets the two side by side using only what the verified citations and the catalog facts support; where a row reads the same for both, that is the point, because the shared history is real and the differences are molecular. Semax and Selank side by side | Feature | Semax | Selank | | --- | --- | --- | | Origin | Analog of the ACTH(4-7) fragment of a pituitary hormone | Analog of tuftsin, a four-amino-acid immune peptide | | Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Thr-Lys-Pro-Arg-Pro-Gly-Pro | | Developed at | Institute of Molecular Genetics, Moscow | Institute of Molecular Genetics, Moscow | | Pathway studied | BDNF- and NGF-related neurotrophic signaling (animal work) | Expression of genes involved in GABAergic neurotransmission (in vitro) | | Verified citation | 1997 clinical study in acute ischemic stroke, not randomized | 2016 in vitro gene-expression study | | Wider evidence | Russian clinical studies, mostly not randomized; no Western randomized trials | Russian clinical studies, mostly not randomized; no Western randomized trials | | Status | Registered medicine in Russia; not FDA-approved for any use | Approved medicine in Russia; not FDA-approved for any use | | Anti-doping | Not named on the WADA list; S0 can apply | Not named on the WADA list; S0 can apply | | Alias | ACTH(4-7)-PGP | TP-7 | Prescribed, pre-mixed ## Get Semax / Selank prescribed, pre-mixed US-supervised · all 50 states [Semax / Selank](https://peptides.build/protocols/semax-selank/)Blend: outside the HHS policy **$183**/mo*$1,099 billed every 6 months* Pay over time at checkout![Klarna](/media/payments/klarna.png)![Afterpay](/media/payments/afterpay.png)![Affirm](/media/payments/affirm.png) Prescription required. Your provider decides if it is appropriate. Compounded medications are not FDA-approved. ## What does the research cover for each? Semax research cited here is a 1997 clinical study, published in a Russian neurology journal, on the use of Semax in the acute period of ischemic stroke; it was not randomized, so it reports experience rather than a controlled comparison. Beyond that, animal work describes BDNF- and NGF-related signaling, the growth-factor pathways involved in nerve cell survival. No Western randomized trial has been published. Selank research cited here is a 2016 in vitro study of how the peptide affected the expression of some genes involved in GABAergic neurotransmission, the main inhibitory signaling system in the nervous system. In vitro work is several steps from a clinical result, and Selank's Russian clinical literature is, like Semax's, mostly not randomized. Neither peptide is positioned on this site for a diagnosed condition; if attention, mood or sleep problems are the reason you are comparing them, that is a clinician conversation first. ## How are Semax and Selank prescribed? Semax and Selank are prescribed through Peptides.build as one protocol, Semax / Selank, rather than as a choice between them. The two peptides arrive in separate vials, each already reconstituted and each labeled with its own concentration, and both are given as subcutaneous injections. A licensed provider decides during intake whether the pairing fits your history; the pairing itself has no published trial behind it, so the provider is weighing two separate bodies of research, not one. Semax and Selank doses are written in micrograms and set by the provider; nothing about amounts is published on this site. Because the two labels differ, each vial gets its own arithmetic, and the free Semax / Selank calculator converts a prescribed dose and a label strength into U-100 syringe units for whichever vial you are holding. It performs arithmetic only and does not recommend a dose. ## Are Semax and Selank FDA-approved or allowed in sport? Semax and Selank are not FDA-approved for any use. In the US both reach patients only as compounded medications prepared by a licensed 503A pharmacy after a prescription, and compounded medications are not FDA-approved; their status as registered medicines in Russia does not transfer. Semax and Selank are not named on the World Anti-Doping Agency Prohibited List, but the list's S0 category covers non-approved substances and can apply to either. Drug-tested athletes should check with their governing body rather than rely on the absence of a name. Prescription, not research grade ## Prescribed Semax and Selank vs research peptides: what is different? Prescribed Semax and Selank are not research chemicals. They are prescription medications: a licensed US provider reviews your intake first, and a licensed 503A pharmacy compounds each one for you by name. Vials sold online as “research use only” skip both steps. What you pay for here is that review, a pharmacy you can name, and a label that says what is in the vial. A research seller’s certificate of analysis is a document the seller controls: it chooses the lab and the sample, and a PDF can be reused, edited or re-dated. No regulator checks it. Prescribed Semax and Selank compared with research-use-only peptides | Point | Prescribed through Peptides.build | Research use only | | --- | --- | --- | | Access | Online intake reviewed by a licensed US provider; prescribed only when appropriate. | No prescription and no clinical review of whether it suits you. | | How it's labeled | A prescription medication compounded for you by name. | Commonly sold labeled “research use only, not for human consumption.” | | Who prepares it | A licensed 503A US compounding pharmacy under state and federal oversight. | Unregulated suppliers, often with no verifiable chain of custody. | | Testing | Third-party tested. | Certificates of analysis are self-reported when provided at all. | | Purity and identity | Prepared to a prescription for a specific patient. | Purity, strength, and even identity are unverified by any independent party. | This compares two care models, not two products. Compounded medications are not FDA-approved, and we do not claim otherwise. What a prescription adds is a licensed provider deciding whether a protocol is appropriate for you and a licensed pharmacy preparing it. [Read the full guide to research vs prescription peptides](https://peptides.build/learn/research-peptides-vs-prescription-peptides/). Common questions ## Semax vs Selank FAQ ### Which is better, Semax or Selank? Neither is better; they are different molecules studied for different pathways, and no published trial has compared them. Through this site they are prescribed together, and the provider decides whether the pairing is appropriate at all. ### Can Semax and Selank be taken together? The catalog's Semax / Selank protocol prescribes them together, in separate vials. Whether that combination is appropriate for you is a provider decision made during intake; the combination itself has not been studied in a published trial. ### Are Semax and Selank the same thing? No. Semax is an analog of an ACTH fragment and Selank is an analog of tuftsin. They share a Moscow origin and a Pro-Gly-Pro tail, and nothing more at the molecular level. ### Are Semax and Selank approved anywhere? Both are registered medicines in Russia, where they were developed. Neither is FDA-approved for any use; in the US they are prescribed only as compounded medications, and compounded medications are not FDA-approved. ### Are Semax and Selank banned in sport? Neither is named on the WADA Prohibited List. The S0 category for non-approved substances can apply to either, so drug-tested athletes should check with their governing body. Prescribed, not mixed at home ## Semax / Selank through Peptides.build A licensed US provider reviews a short online intake and decides whether a protocol is appropriate. A US 503A pharmacy prepares it already reconstituted, labels the concentration and ships it cold-chain. Dosing is set by the provider and is not published on this site. - [Semax / Selank protocol: pricing, who it is for, FAQ](https://peptides.build/protocols/semax-selank/) - [All cognitive protocols compared](https://peptides.build/protocols/cognitive/) - [Semax / Selank Calculator: units, reconstitution and dosing chart](https://peptides.build/tools/semax-selank-calculator/) - [What is Semax?](https://peptides.build/learn/what-is-semax/) - [What is Selank?](https://peptides.build/learn/what-is-selank/) - [What is DSIP?](https://peptides.build/learn/what-is-dsip/) Sources ## References 1. Usage of neurospecific peptide substance Semax in acute period of ischemic insult. *Neurology Bulletin (Nevrologicheskiy Vestnik)*, 1997. [doi:10.17816/nb80150](https://doi.org/10.17816/nb80150)Study type: Clinical study (acute ischemic stroke; not randomized) 2. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. *Frontiers in Pharmacology*, 2016. [doi:10.3389/fphar.2016.00031](https://doi.org/10.3389/fphar.2016.00031)Study type: In vitro study (gene expression) Citations are listed with their study type so the evidence can be weighed. Review articles summarize other studies; animal and in vitro findings do not describe outcomes in people. This article is educational and is not medical advice. Neither compound is FDA-approved for any use, and compounded medications are not FDA-approved. No results are implied or guaranteed. Talk to a licensed provider about your own history before starting any protocol.