Peptifact

Selank Dosage: Two Randomised Papers, One Journal, and a Search Count That Doubles the Evidence

Selank has no US label and no trial registration anywhere. We counted the human evidence properly and found it is two Russian-language randomised papers in a single journal — half of what a PubMed search appears to show.

Robert F · Edited by Caroline S · Published 2026-09-10

Illustration: A clear glass vial with lyophilized powder and a magnifier on a slate surface.
Illustration

Selank is one of two peptides — Semax is the other — that arrive in English-language discussion with an unusual claim attached: that they are not experimental at all, but registered medicines with decades of clinical use behind them. The claim is half true, and the half that is false is the half that matters for a dose. This page reports what the sources state, counts the human evidence rather than repeating a search total, and does not recommend anything. Our page on the questions we ask of any dosage figure sets out what separates a label figure from a convention. How brands appear on this site is set out on our disclosure page.

What exists, and what does not

Selank is a synthetic heptapeptide. Its first four residues, Thr-Lys-Pro-Arg, are tuftsin — a fragment of an immunoglobulin heavy chain that the body produces itself. The synthetic addition is Pro-Gly-Pro at the C-terminus, made to slow enzymatic breakdown rather than to alter the molecule's behaviour at its target. It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, and it is registered as a medicine in Russia.

It is not registered in the United States. A search of DailyMed, the US drug label database, for Selank on 2026-09-10 returned zero records. There is therefore no labelled dose, no titration schedule, no maximum, and no approved indication to attach one to.

There is also no trial registration. Searching ClinicalTrials.gov for Selank returns ten studies, and every one of them is a false match: a transcranial magnetic stimulation study of object recognition, two brivaracetam epilepsy trials, a neurofeedback study in dyslexia, a hearing-aid speech-processing study, a high-altitude cognition study. None administers Selank. The registry holds no interventional record of this compound at all.

Counting the evidence rather than the search result

This is where Selank pages usually go wrong, and it is worth showing the arithmetic because anyone can reproduce it.

A plain PubMed search for selank on 2026-09-10 returned 136 records. That is the number most write-ups quote. Restricting the identical search to the title and abstract fields — selank[tiab] — returns 68. Restricting further to records tagged for humans returns 15.

Query Records
selank (all fields) 136
selank[tiab] 68
selank[tiab] AND humans[mh] 15
selank AND randomized controlled trial[pt] 3 (one a false match)

The excess is not a rounding artefact. The unrestricted result contains a study of nutrient thresholds in wadeable streams, one on the translucency of dental ceramics, one on mealworm frass in animal feed and one on umami peptides in black tea. The string is matching something other than the compound. The commonly quoted "over a hundred studies" is, on inspection, fifteen human-tagged papers and sixty-eight mentions.

The randomised subset is smaller still. PubMed's randomised-controlled-trial filter returns three records for Selank. One is a study of strength and hypertrophy adaptations in untrained lifters, which has nothing to do with the peptide. The other two are genuine, and they are:

Two randomised papers, seven years apart, in one journal, in one language. That is the whole of the registered-medicine claim's clinical backing as it appears in the international literature. It is not nothing — a compound with two randomised trials has more behind it than most of the research-peptide catalogue, which has none. It is also not what "decades of clinical use" implies to an English-speaking reader, and no page we found states the count.

The remainder of the genuine literature is animal work, much of it recent and much of it in one journal as well: Bulletin of Experimental Biology and Medicine carries Selank studies on morphine withdrawal in rats, ethanol-induced memory impairment, colon microbiota under restraint stress and liver morphology under foot-shock stress, published between 2019 and 2022.

What the sources state as a quantity

With no label and no registration, every figure below is a convention rather than an instruction, and each is reported here with where it comes from.

Route Figure stated Where it comes from Date
Intranasal 250–300 µg per day, divided between nostrils Consistent with the concentration of the Russian nasal preparation used in the clinical papers 2008, 2015 papers
Subcutaneous ~100–300 µg per day Vendor and protocol pages only; no published human study located Commonly cited, undated
Course length 10–14 days, repeated The anxiety papers describe courses of this order 2008, 2015

Two things are worth stating plainly about that table. First, the nasal route is the one with a documented origin — the Russian preparation is a nasal solution, the clinical papers used it nasally, and the circulating nasal figures are at least consistent with that concentration. Second, the subcutaneous figures have no human study behind them whatsoever. Selank sold as a lyophilised powder for reconstitution is being given by a route that the two randomised papers did not use, at quantities transferred across from the nasal figures on no stated basis.

The arithmetic, if a figure is being converted

Reconstitution volume is the variable that changes what any stated quantity means, and at Selank's scale the syringe itself becomes a source of error.

A 5 mg vial in 2 mL of bacteriostatic water gives 2.5 mg/mL. A stated 300 µg is then 0.12 mL — 12 units on a U-100 insulin syringe. A stated 100 µg is 0.04 mL, or 4 units.

Four units is close to the practical resolution of a standard U-100 syringe, whose graduations are one unit and whose plunger and dead space introduce error of a comparable size. That is a measurement observation, not advice: at these volumes, the difference between two people following the same stated figure can be a large fraction of the figure. Our reconstitution page carries the arithmetic for other vial-and-volume combinations, and our documentary guide to insulin syringes works through where dead space goes.

What is not established

  • No approved label anywhere in the United States, so no dose has been reviewed by a regulator that publishes its reasoning.
  • No trial registration anywhere, so no protocol, no pre-specified endpoint and no results record exist to check a claim against.
  • No published human study of the injected route, which is the route the powder sold as Selank is prepared for.
  • No independent replication outside Russia. Both randomised papers come from the same national research community and the same journal; nothing in the English-language literature repeats them.
  • No long-term safety data of the kind an approval would require.

What a reader can check in five minutes

Every claim above is reproducible in a browser, which is the point of publishing the queries rather than the conclusions:

  1. Search DailyMed for selank — expect zero records.
  2. Search ClinicalTrials.gov for selank — read the ten titles and see that none administers it.
  3. Run the three PubMed queries in the table and compare the counts.
  4. Apply PubMed's randomised-controlled-trial filter and read the three titles.

If a page tells you Selank is backed by extensive clinical trials, those four checks are the ones that test the claim. MuscleLedger's nootropic-peptide coverage approaches the same compounds from a performance angle, and our cognitive peptides overview places Selank alongside the others in its class.

Our Semax dosage page counts the literature for the other Russian-registered peptide, which turns out to have a different shape of evidence again. For the general question of how to test any figure you are shown, how to read a dosing claim sets out the checks.

Sources and dates

Opened 2026-09-10: DailyMed's SPL search API for selank (zero records); the ClinicalTrials.gov v2 API, both query.intr and query.term, for Selank (ten records, all false matches, none administering the compound); PubMed record counts through the NCBI E-utilities for selank (136), selank[tiab] (68), selank[tiab] AND humans[mh] (15) and the randomised-controlled-trial publication-type filter (3, one a false match); the PubMed summaries for the two Russian-language randomised papers in Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2008 and 2015. A control query with a known answer was run in the same session to confirm the query shape was sound. Corrections go to the contact page.

Frequently asked questions

What is the standard Selank dose?

There is no standard in any regulatory sense. No product containing Selank has an FDA-approved label, so there is no official dose, no titration schedule and no maximum. The figures that circulate are 250 to 300 micrograms per day intranasally and roughly 100 to 300 micrograms per day subcutaneously. The nasal figures are at least consistent with the concentration of the Russian nasal preparation the clinical papers used; the injected figures correspond to no published human study we could locate.

Are there human trials of Selank?

There are published human studies, but far fewer than a search suggests, and none is registered. ClinicalTrials.gov holds no interventional registration of Selank at all — the ten records a search returns are false matches on unrelated trials. In PubMed, the randomised human evidence comes down to two Russian-language papers in one journal, the Korsakov Journal of Neurology and Psychiatry, from 2008 and 2015, both in anxiety disorders.

Why do different sources quote such different numbers of Selank studies?

Because most of them quote the unrestricted PubMed count without checking what it contains. Searching for selank returns 136 records; restricting the search to titles and abstracts returns 68, and restricting to human-tagged records returns 15. The excess is the string matching unrelated papers — studies of wadeable streams, dental translucency and animal feed appear in the raw result. Anyone can reproduce the three counts in a browser and see the gap.

Is Selank an approved medicine anywhere?

Not in the United States, where DailyMed holds no record of it. Selank was developed at the Institute of Molecular Genetics in Moscow and is registered as a medicine in Russia, which is why the clinical papers describing it are Russian-language and why the nasal concentration is the one figure with a documented origin. A registration in one country is not an FDA approval, and it does not put a dose on a vial bought as a research chemical.

How does Selank differ from Semax?

They are different molecules from the same Russian research programme and are frequently confused. Semax is derived from a fragment of ACTH; Selank is derived from tuftsin, an immune-system peptide, extended with a Pro-Gly-Pro tail. They share a development history, a country of registration and an absence from the Western trial registry, but not a structure, a target or an evidence base. Our Semax page counts that compound's literature separately.

Is Selank detectable in doping tests?

Selank has appeared in the anti-doping analytical literature, which is generally the first sign that a compound is circulating in sport: it turns up in screening methods for small peptides and in analyses of seized pharmaceutical preparations. It is not named on the 2026 WADA Prohibited List, which is not the same as being permitted — the list's classes are written to cover substances of similar structure or effect, and S0 covers any pharmacological substance with no current approval by any governmental regulatory health authority for human therapeutic use. A tested athlete should treat that as an open question rather than an absence.