This article is for laboratory and research information only. All products referenced are supplied strictly for research use and are not for human or veterinary use. Last reviewed: October 2026.
Quick answer: Selank is a synthetic seven-amino-acid peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) developed in Russia as a more stable analogue of tuftsin, a naturally occurring immune peptide. It is studied in laboratory and animal models of neuropeptide signalling, GABA-related gene expression and immune signalling. It is not a licensed medicine in the UK, where it is sold as a research chemical for laboratory use only.
Selank at a glance
| Type | Synthetic heptapeptide (7 amino acids) |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Based on | Tuftsin (Thr-Lys-Pro-Arg), plus a Pro-Gly-Pro extension |
| Developed by | Institute of Molecular Genetics, Russian Academy of Sciences |
| Related peptide | Semax, from the same research programme |
| UK status | Research chemical; not an MHRA-licensed medicine |
What is Selank?
Selank is a heptapeptide, meaning a chain of seven amino acids. Its first four amino acids (Thr-Lys-Pro-Arg) are the sequence of tuftsin, a short peptide that occurs naturally in the body as a fragment of an immune protein. Tuftsin breaks down quickly in biological fluids, so researchers added a Pro-Gly-Pro sequence to the end. That extension was designed to make the peptide more resistant to enzymatic breakdown.
Selank was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is registered as a medicine in Russia, but it is not licensed in the UK, EU or US.
What has Selank been studied for?
Most published Selank research comes from Russian research groups and uses cell cultures and animal models. The main areas are:
- Behavioural models: rodent studies of anxiety-related and stress-related behaviour.
- GABAergic system: studies of how Selank affects the expression of genes involved in GABA signalling in neural tissue.
- Enkephalin breakdown: research into Selank's effect on enzymes that degrade enkephalins, which are natural opioid peptides.
- Immune signalling: reflecting its tuftsin origin, studies of cytokine expression and immune-related pathways.
- Peptide stability: Selank is a useful model for studying how small sequence changes affect a peptide's stability.
Because most of the literature comes from a small number of groups in one country, independent replication is limited, and robust clinical data outside Russia is scarce.
Selank vs Semax
Selank and Semax came out of the same Russian research programme on regulatory peptides, and they are often studied together. The difference is their starting point:
- Selank is based on tuftsin, an immune-related peptide, and research focuses on anxiety-related, GABAergic and immune models.
- Semax is based on a fragment of ACTH (adrenocorticotropic hormone), and research focuses more on neurotrophic factors such as BDNF and on cognitive and neuroprotection models.
Both use a similar Pro-Gly-Pro extension to improve stability.
Is Selank legal in the UK?
Selank is not a licensed medicine in the UK and is not approved by the MHRA for human or veterinary use. It is sold in the UK as a research chemical for laboratory use only.
What to check when buying Selank in the UK
- A batch-specific Certificate of Analysis (CoA) confirming the sequence and purity.
- HPLC purity, with the chromatogram shown.
- Mass spectrometry confirming the molecular weight matches Selank.
- Third-party testing rather than in-house results only.
Our guide on how to read a peptide Certificate of Analysis explains what to look for. Selank is available here as a Selank 5mg lyophilised vial.
Storage
Lyophilised Selank is best stored frozen at around -20°C for long-term storage, or refrigerated at 2–8°C for short-term use, away from light and moisture. Once reconstituted, keep it refrigerated and use it within its stability window. See our storage & reconstitution guide and concentration calculator.
Selank FAQ
How many amino acids are in Selank?
Seven, making it a heptapeptide.
What is tuftsin?
Tuftsin is a naturally occurring four-amino-acid peptide (Thr-Lys-Pro-Arg) involved in immune function. Selank is built on the tuftsin sequence.
Why was Pro-Gly-Pro added to Selank?
To make the peptide more resistant to breakdown by enzymes than tuftsin is on its own.
Is Selank the same as Semax?
No. They come from the same research programme but have different parent molecules: tuftsin for Selank and an ACTH fragment for Semax.