Selank vs Semax: Nootropic Research Peptides Compared

At a glance

Sources: PubChem, Selank, CID 11765600, National Library of Medicine. PubChem, ACTH (4-7), Pro-Gly-Pro (Semax), CID 9811102, National Library of Medicine. Siebert A et al, Tuftsin: properties and analogs, Curr Med Chem, 2017. Alzheimer's Drug Discovery Foundation, Cognitive Vitality report: Semax, Read 25 October 2026.

What is Selank?

Selank is a lab-made analogue of tuftsin. Tuftsin is a four amino acid peptide that the body releases from an antibody protein, and it was first studied for its effects on immune cells. Chemists added three more amino acids, Pro-Gly-Pro, to the end of tuftsin to make Selank. In Russian papers it is described as a candidate anti-anxiety peptide.

Glow Labs lists Selank in a 10mg vial. It is out of stock for now; message us on WhatsApp to pre-order.

Sources: PubChem, Selank, CID 11765600, National Library of Medicine. Siebert A et al, Tuftsin: properties and analogs, Curr Med Chem, 2017. Zozulia AA et al, Zh Nevrol Psikhiatr Im S S Korsakova, 2008 (Russian).

What is Semax?

Semax starts with four amino acids from ACTH, the pituitary hormone that drives the adrenal glands, then carries the same Pro-Gly-Pro tail. The foundation review says Semax keeps some of ACTH's brain effects but lacks its hormone activity. Our full guide on what Semax is goes deeper into its history and evidence. Glow Labs stocks Semax research vials in 10mg.

Sources: PubChem, ACTH (4-7), Pro-Gly-Pro (Semax), CID 9811102, National Library of Medicine. Alzheimer's Drug Discovery Foundation, Cognitive Vitality report: Semax, Read 25 October 2026.

Sequences compared

Here are the two peptides written one amino acid per column, using one-letter codes.

The bold letters in positions 5 to 7 are identical. That is the Pro-Gly-Pro tail. Positions 1 to 4 share nothing. In Selank they spell tuftsin (T-K-P-R). In Semax they spell a slice of ACTH (M-E-H-F). So the two are cousins by design, not by origin.

Sources: PubChem, Selank, CID 11765600, National Library of Medicine. PubChem, ACTH (4-7), Pro-Gly-Pro (Semax), CID 9811102, National Library of Medicine. Siebert A et al, Tuftsin: properties and analogs, Curr Med Chem, 2017.

Why the shared tail

Short natural peptides like tuftsin and ACTH pieces tend to break down quickly in the body. Researchers found that adding Pro-Gly-Pro made the ACTH fragment's effects last far longer, up to 20 to 24 hours in animal tests. Selank carries the very same tail on its tuftsin core. In other words, the tail is a design feature the two molecules share.

Sources: Siebert A et al, Tuftsin: properties and analogs, Curr Med Chem, 2017. Alzheimer's Drug Discovery Foundation, Cognitive Vitality report: Semax, Read 25 October 2026.

Where they came from

Both peptides were developed in Russia. The foundation review of Semax names the Russian Academy of Sciences as its source. Selank's clinical papers also come from Russian groups and journals. That shared origin is why the two are so often sold side by side.

It also explains a shared weakness. Much of the human work on both is published in Russian and is hard for other scientists to check.

Sources: Alzheimer's Drug Discovery Foundation, Cognitive Vitality report: Semax, Read 25 October 2026. Zozulia AA et al, Zh Nevrol Psikhiatr Im S S Korsakova, 2008 (Russian).

What was studied

Only two of these studies involved people. The 2008 study is a Russian clinical paper with an English abstract only. The 2020 study measured brain scans, not health outcomes.

Sources: Slominsky PA et al, Peptides semax and selank affect the behavior of rats with 6-OHDA induced PD-like parkinsonism, Dokl Biol Sci, 2017. Volkova A et al, Selank administration affects the expression of some genes involved in GABAergic neurotransmission, Front Pharmacol, 2016. Zozulia AA et al, Zh Nevrol Psikhiatr Im S S Korsakova, 2008 (Russian). Eremin KO et al, Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents, Neurochem Res, 2005. Panikratova YR et al, Functional connectomic approach to studying Selank and Semax effects, Dokl Biol Sci, 2020.

How they may work

The ideas differ between the two, which fits their different parents.

• Selank. The 2016 rat study found changes in genes linked to GABA, the brain's main calming messenger. The 2008 paper looked at enkephalins, natural pain and mood peptides, in blood.
• Semax. Animal work points to effects on serotonin markers and on BDNF, a nerve growth factor.

These are open hypotheses from early studies. Neither mechanism is settled.

Sources: Alzheimer's Drug Discovery Foundation, Cognitive Vitality report: Semax, Read 25 October 2026. Volkova A et al, Selank administration affects the expression of some genes involved in GABAergic neurotransmission, Front Pharmacol, 2016. Zozulia AA et al, Zh Nevrol Psikhiatr Im S S Korsakova, 2008 (Russian). Eremin KO et al, Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents, Neurochem Res, 2005.

Approval status

The foundation review reports that Russia uses Semax as a medicine. We found no approval for Selank in the sources we read. The October 2026 Poisons Standard does not name either peptide. Neither appeared in the TGA pages read for this comparison either, so we say nothing about their Australian registration.

Glow Labs supplies both for laboratory research only, under its research use only notice.

Sources: Alzheimer's Drug Discovery Foundation, Cognitive Vitality report: Semax, Read 25 October 2026. Therapeutic Goods (Poisons Standard, October 2026) Instrument 2026 (F2026L01327), Federal Register of Legislation, Australian Government.

Stock and storage

Semax is in stock in 10mg vials. Selank is on pre-order. DSIP is the third peptide in our cognitive research area. All three arrive as freeze-dried powder. Store them sealed, cold and dark, and read our guide on storing research peptides for fridge and freezer choices.

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