Semax and Selank: two Russian peptides with a literature problem

Semax and Selank both came out of the Institute of Molecular Genetics in Moscow, both are registered medicines in Russia, and both have been in clinical use there for decades. In the EU and the US they are neither approved nor, for practical purposes, studied.

That combination — real clinical history, almost no Western evidence base — makes them among the harder compounds in this catalog to write about honestly. So let us take the difficulty head on.

What they are

Semax is a synthetic heptapeptide derived from the ACTH(4-10) fragment, modified for stability. It carries none of the hormonal activity of full ACTH; the fragment was chosen for its neurotropic properties. The mechanistic literature describes effects on BDNF expression and on dopaminergic signalling.

Selank is a synthetic analogue of tuftsin, an immune-derived tetrapeptide, extended into a stable heptapeptide. In Russia it was developed and registered specifically as an anxiolytic.

Our catalog lists the acetylated, amidated versions — AC-Semax-NH₂ and AC-Selank-NH₂ — chemically modified at both termini for greater stability than the parent peptides. That prefix on the label is not decoration; it is a different molecule with different pharmacokinetics from the one most published work used, and any page that quotes Semax studies beside an AC-Semax-NH₂ vial should say so. We just did.

What the evidence actually looks like

Here is the uncomfortable summary:

• A PubMed search for either compound returns on the order of a hundred-plus records, the majority mechanistic or animal work.
• Russian clinical trials exist — Selank has been studied there for generalised anxiety disorder, with reports of efficacy comparable to benzodiazepines without sedation or dependence — but most of that work is published in Russian-language journals, and it does not meet the evidentiary standard the EMA or FDA would require for approval.
• There is no Western pharmaceutical sponsor. The compounds are not patentable in most Western jurisdictions in a way that would justify funding a large trial, so the trials have not been funded, and on current incentives they will not be.
• Specific claims frequently attached to Semax — ADHD, cognitive enhancement in healthy people — have no controlled clinical trial behind them in any language we can verify.

None of that means the compounds do nothing. It means the question has not been answered to the standard the rest of this site’s articles are able to cite, and we are not going to paper over that with an impressive-sounding sentence.

Why we stock them

Because there is a real research literature, a real registration history in another jurisdiction, and genuine mechanistic interest — the tuftsin and ACTH-fragment lineages are legitimate starting points, not invented ones. Compounds where the West has never run the trial are exactly the kind of thing a research catalog exists to supply.

What we will not do is take advantage of the gap. A literature that is hard to read in English is not the same as a literature that says what a vendor wants it to say.

Practical notes

• Check the molecule. AC-Semax-NH₂ ≠ Semax; AC-Selank-NH₂ ≠ Selank. If you are replicating published work, that distinction belongs in your methods section.
• Storage is the manufacturer’s: room temperature, away from light and moisture, sealed. Detail here.
• Language. If you read Russian, the primary literature is considerably larger than the English-indexed record suggests. If you do not, treat the English-language summaries — including this one — as second-hand.

What we supply

Nootropics Booster (AC-Semax-NH₂) 30 mg and AC-Selank-NH₂ 10 mg, Nordic Peptides, shipped as supplied by the manufacturer, batch documentation on request. The third compound on this shelf, DSIP, has a longer history and a weaker one — worth reading before it gets grouped with these two.

Research use only. Not for human or veterinary use, and nothing here is medical advice or a suggestion that these compounds treat anything.