Semax + Selank + DSIP

Where the name "Semax + Selank + DSIP" comes from

The pairing at the centre of this name is documented, and the document is a federal one. The United States Food and Drug Administration's briefing package for the Pharmacy Compounding Advisory Committee, dated 11 May 2026 and prepared for the committee's meeting of 23 and 24 July 2026, states in its own words that "Semax products are marketed as single ingredient formulations and in combination with selank," and describes one website offering a "50:50" combination of Semax and Selank as both an injectable and a nasal spray. That statement is taken from the briefing document itself rather than from any research paper.

So a United States regulator has recorded, in writing, that this pairing is being sold. What no source records is anyone having studied it. The same document's evidence review sets Selank aside as "a different peptide" outside the scope of its Semax evaluation, and it makes no finding about a three-component product at all — the federal record covers the pair, not the trio.

Adding DSIP to the name is community and market usage that Peptide Health Lab neither coined nor endorses, and its origin is not documented in the indexed literature. A PubMed search for Semax AND Selank AND DSIP on 1 September 2026 returned 1 record: a 2026 narrative review of therapeutic peptides in orthopaedics, which places delta sleep-inducing peptide among "recovery-enhancing agents" in one clause and Selank and Semax among "neuroactive peptides" in the next, proposes no combination, and administers nothing. That review also states that clinical trials of the peptides it surveys are currently lacking.^[1]

What's in it and why people combine them

Semax is a synthetic analogue of a fragment of adrenocorticotropic hormone, studied principally in Russia and principally for ischemic stroke and cognition. Selank is a synthetic analogue of the immunopeptide tuftsin, studied principally as an anxiolytic. DSIP is a nonapeptide isolated from rabbit cerebral venous blood in Basel in 1977 and named for a sleep effect its own subsequent literature never established.

The reason the three are grouped is that each is described as acting on a different part of the same broad territory — alertness, anxiety, sleep. That is a description of three mechanisms placed next to one another. No published measurement was ever taken with more than one of them present.

Two of the three come from one research lineage, and that is measurable rather than merely arguable. Of the 10 records PubMed returned for semax[nm] AND selank[nm] on 1 September 2026, 9 carry Nikolai F. Myasoedov as an author under one or other of the transliterations PubMed indexes for him. The tenth is a forensic analysis from a Belgian public-health laboratory.^[7] Across the wider corpora the concentration falls to roughly half: 88 of the 176 records for semax[nm] and 31 of the 69 records for selank[nm], counting the two surname spellings PubMed indexes for him — Myasoedov and Miasoedov — with the initials N.F., and measured on the same date. Half of each corpus is a concentration worth naming; it is not almost all of either, and this page does not say it is. DSIP's foundational work comes from a different group in a different country. None of this makes any individual result wrong. It means that where a finding about Semax or Selank appears more than once, "reproduced" and "independently confirmed" are claims to check against an author list rather than assumptions to make.

What the evidence says about the combination

Semax and Selank have been placed side by side in the same experiment repeatedly, across two decades, and never given together. That distinction is the whole content of this section, because a page that blurred it would be presenting parallel arms as combination data.

In 2001, a human serum assay found both peptides inhibited enkephalin-degrading enzymes, and reported a separate half-maximal inhibitory concentration for each one.^[5] In the same year, Wistar rats bred for differing resistance to emotional stress received either DSIP or the ACTH(4-10) analogue ACTH(4-7)-Pro-Gly-Pro — the heptapeptide marketed as Semax — as distinct intraperitoneal injections, and their effects on Fos immunoreactivity in the paraventricular nucleus and limbic structures are reported distinctly and differ from each other.^[6] In 2017, rats with 6-hydroxydopamine-induced parkinsonism received both peptides in the same study: neither changed motor activity in the elevated cross-shaped maze or passive defensive behaviour, and only Selank reduced anxiety.^[3] Also in 2017, both appeared in a mouse embryonic stem cell panel in which every compound was tested individually.^[4] And in 2020, 52 healthy adults underwent resting-state functional MRI before and after receiving, in the abstract's own construction, "either Semax, or Selank, or placebo."^[2]

Five experiments, three species, one placebo-controlled human session, and in not one of them was a second peptide present alongside the first. Comparing two compounds is the opposite of combining them: the parallel-arm design exists precisely to keep their effects apart.

The three-way question returns nothing at all. On 1 September 2026, PubMed returned 1 record for Semax AND Selank AND DSIP, 0 records for that query AND-ed with (combination OR combined OR co-administration OR coadministration OR "administered together"), and 0 records for the controlled-vocabulary intersection semax[nm] AND selank[nm] AND "Delta Sleep-Inducing Peptide"[Mesh] — a field-qualified search that would find a paper regardless of how it spelled the compounds. semax[nm] AND selank[nm] AND "Drug Therapy, Combination"[Mesh], the index term applied to studies of drugs given together, also returned 0.

No published test of additivity exists between any pair of these three, in either direction, so there is no result to report either way. Combination claims about them rest on nothing that was measured.

Where the evidence is weak

The gap between what is sold and what is studied is total. A federal briefing document describes a marketed 50:50 Semax-and-Selank product, and the indexed literature contains no study of it. A Belgian public-health laboratory that analysed two seized preparations containing these peptides stated that, to its knowledge, they have not completed any clinical trials, and reported finding them freely available online as lyophilized powder for injection and in nasal sprays.^[7] Availability, and even federal documentation of availability, is not evidence of anything except availability.

The one substantial human experiment involving two of these compounds is not what it is usually described as. It enrolled 52 healthy adults rather than patients, its outcome was resting-state functional connectivity rather than any symptom or function a person would notice, the analysis that separated the two peptides' effects is described by its own authors as post hoc, and PubMed does not index it as a randomized controlled trial.^[2]

Where a combined result would most plausibly have shown up, the reported result was null for both compounds. In the parkinsonism model, neither peptide changed motor activity or passive defensive behaviour; the only positive finding belonged to one of them, on one measure, in one maze.^[3]

Three components, three unrelated outcome families. The one review that names all three sorts them into two different classes with two different mechanisms: delta sleep-inducing peptide among "recovery-enhancing agents" said to target circadian and mitochondrial regulators, and Selank and Semax among "neuroactive peptides" said to act on brain-derived neurotrophic factor and the HGF/c-Met pathway.^[1] Semax's literature measures stroke recovery and cognition, Selank's measures anxiety, DSIP's measures sleep. There is no endpoint on which all three have been assessed, so there is not even a shared measure against which a combined effect could be compared.

Dosing and protocol ranges are not on this page. They belong on the individual compound pages, where each figure sits beside the population, route and study that produced it. Nothing on this page is a schedule, a sequence or a quantity, and the concentrations recorded in the federal document are a description of a product someone is selling, not a description of anything that was tested.

Questions to bring to a provider

The productive version of this conversation is not which of the three to add. It is what the problem is and what has been shown to change it.

• What is the actual target — a diagnosed condition, a cognitive complaint, a sleep problem, an anxiety problem — and what does the evaluated standard of care offer for that one specifically?
• Given that the largest human experiment involving two of these compounds gave them to healthy volunteers as separate groups and measured brain connectivity rather than symptoms, what would it take for that result to bear on a person's complaint?^[2]
• Two of the three components' literatures are concentrated in one research group, though not exhausted by it: measured on PubMed on 1 September 2026, 9 of the 10 records naming both compounds carry that group's founding author, and so do about half of each compound's own corpus. What weight should a finding carry before anyone outside that group has reproduced it?
• These compounds are marketed as injectables and nasal sprays and, according to the laboratory that analysed seized preparations of them, have not completed any clinical trials. What is known about identity, purity and content in material with no approved specification?^[7]
• What objective measure would show whether anything changed, at what interval, and what result would end the experiment?

Anti-doping status

None of Semax, Selank or DSIP is named anywhere on the World Anti-Doping Agency Prohibited List in force for 2026, or on the 2026 Monitoring Program, or in the 2026 Explanatory Note. All three documents were retrieved on 1 September 2026 as published PDFs by way of the United States Anti-Doping Agency's prohibited-list page, and a full-text search of the extracted text for semax, selank, delta sleep, DSIP and tuftsin returned zero occurrences across all three.

The control that shows the search works covers one of those three documents, and is reported here as covering one. In the Prohibited List, control searches of the same extracted text for BPC-157, tesamorelin and MOTS-c each returned two occurrences, so a zero in that document describes the document rather than a broken search. The identical control terms return zero in the Monitoring Program and zero in the Explanatory Note, which establishes nothing about either — so neither of those two negatives rests on a text search. Both are short enumerated documents and both were read in full on the same date: the 2026 Monitoring Program is a single page listing six numbered categories, and the 2026 Explanatory Note is four pages of numbered modifications to named sections. Neither names any of these three peptides. All of this was read from the documents themselves, never from a research paper.

One heading on the 2026 List deserves naming here, because a reader will find it. Section S2.2.2 prohibits "Corticotrophins and their releasing factors, e.g. corticorelin and tetracosactide," and Semax is derived from a fragment of adrenocorticotropic hormone. The List does not name Semax there or anywhere else, and, unlike section S2.2.3 — which reaches growth hormone "its analogues and fragments" in so many words — S2.2.2 names neither analogues nor fragments. Whether an ACTH fragment analogue falls inside that class is a question for an anti-doping organization with the athlete's own facts in front of it, and this page does not answer it in either direction.

Absence from the List is never a statement that a substance is permitted. Section S0 reaches any pharmacological substance not addressed by another section and with no current approval by any governmental regulatory health authority for human therapeutic use; all substances in that class are Specified Substances. For DSIP, no registration by any national medicines regulator was found, and the conventional reading of that criterion stands.

For Semax and Selank it does not, and this page says so rather than guessing. The FDA briefing document of 11 May 2026 states, more than once, that Semax is a registered drug in Russia available as nasal drops, cites the Russian State Register of Medicines accessed 4 December 2025 for it, and answers its own summary-table question about recognition in foreign pharmacopoeias with "Russian Pharmacopoeia." Russian pharmaceutical trade press, reporting on decisions the Russian Ministry of Health published on 20 January 2026, states that state registration of seventy-one medicines was cancelled at the registration holders' own request and names both Semax and Selank among them. Those two accounts cannot both describe the present. The register itself could not be used to settle which does: on 1 September 2026 the search endpoint cited in the FDA document's own footnote returned HTTP 200 with no result rows, and a control query on the same endpoint for a medicine certain to be registered returned HTTP 200 with no result rows as well — an empty result that is a failure of the query rather than a finding about the register.

This page therefore asserts no S0 conclusion for Semax or for Selank. Whether a substance registered by a national regulator until January 2026 has "no current approval by any governmental regulatory health authority" is precisely the fact S0 turns on, and it is the fact this page could not verify.

Nothing here is clearance, and List standing is a separate question from clinical standing. The Belgian public-health laboratory that identified Semax and Selank in seized preparations recorded that the compounds had, to its knowledge, completed no clinical trials and were circulating as injectable powder and nasal sprays.^[7] The Prohibited List is reissued every year and sections renumber between editions, so a competing athlete should confirm the current year's list with their national anti-doping organization rather than relying on this page.