Selank: what it is, how it is supplied, and how to choose a research supplier

Selank is a synthetic peptide of seven amino acids: threonine, lysine, proline, arginine, proline, glycine, proline: written Thr-Lys-Pro-Arg-Pro-Gly-Pro or TKPRPGP.

The first four residues are the natural tetrapeptide tuftsin (TKPR); the last three, Pro-Gly-Pro, were added to make the chain more stable. Its molecular weight is about 751 Da.

It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences, in the same laboratory that designed Semax, and the two are often listed side by side because they share the Pro-Gly-Pro tail and a similar size.

On a bench it is unremarkable to look at: a white to off-white lyophilized powder with no color of its own, so the sequence, mass and quantity in mg stated on the label and the product page are what define it.

In the catalog, Selank is sold as a research reagent: a sealed, labeled vial of lyophilized powder. Research use only. Not for human or veterinary use.

Because they come from the same laboratory and ship in the same sizes, Selank and Semax are frequently confused in listings. They are different molecules.

Each is a separate compound, in its own vial, with its own label naming it.

Research Selank comes as a lyophilized (freeze-dried) powder in a glass vial closed with a rubber septum and an aluminum crimp cap. The label states the compound, the net quantity in milligrams and the words "research use only".

The catalog offers two sizes: 5 mg and 10 mg: and the price per milligram is lower on the 10 mg vial.

The live table at the top of this page is read directly from the catalog, so the prices shown there are the prices in force today. See Selank in the catalog for availability.

What "5 mg" means on the label

The number is the net mass of Selank powder in the vial, as filled, and it is the quantity printed on the label.

Five milligrams is a very small amount of solid: often no more than a thin white film at the bottom or on the wall of the glass. An almost empty-looking vial is the normal appearance of a 5 mg fill, not a short fill.

Acetate or trifluoroacetate

Synthetic peptides are usually supplied as a salt. Most research Selank is the acetate; some manufacturers leave the peptide as the trifluoroacetate (TFA) salt from purification.

The COA should state which, and a good supplier specifies the counter-ion on the product page. Neither changes the sequence, but the residual TFA content is a purity question.

For a white, odorless powder with no distinguishing feature, a usable certificate from any supplier carries:

• The laboratory's name and a verifiable identifier. Independent labs (Janoshik is the reference for this market) give each test a number that anyone can look up on the lab's site.
• The lot number: with the task number and verification key the laboratory confirms.
• HPLC purity as a measured percentage. "≥ 98 %" printed without a task number the lab confirms is a claim, not a measurement.
• Identity: the report names Selank as the compound found. Where a lab adds a mass spectrum as an option, Selank reads about 751 Da; a mass around 813 Da would mean Semax.
• The date of the test. A certificate older than a few months describes a lot that has probably sold through.
• A photograph of the tested vial wearing the supplier's own label. A manufacturer's certificate showing a bare vial says nothing about what this supplier bottled.

The full checklist, with examples of what a doctored certificate looks like, is in how to read a peptide COA.

Further reading: epithalon data sheet, sermorelin data sheet, Glutathione peptide and AOD-9604 peptide.

Selank is stable as a lyophilized powder when it is kept cold, dark and dry. The catalog's storage line for the sealed vial:

• Temperature: −20 °C for long-term storage, in the sealed vial, away from light and moisture.
• Light: keep the vial in its box or in an opaque container.
• Moisture: keep the vial sealed. Let a cold vial reach room temperature before removing it from its bag, so no condensation forms on the glass.
• Shelf life: 24 months from the fill date for a sealed vial stored as above.

Shipping at ambient temperature for a few days does not degrade the sealed powder; that is why research peptides ship without cold packs. The general rules, size by size, are in lyophilized peptides: storage and shelf life.

"Selank" returns a mix of clinics, marketplaces and research suppliers, and "selank for sale" adds resellers. To sort them, ask six questions of the product page: not of the marketing.

1. What does the supplier's lab documentation cover? Before buying from any supplier, check which compounds and sizes its reports name, and that each one can be looked up on the laboratory's site.
2. Is the vial sealed, with a printed label naming the compound, its net mass in mg and "research use only"?
3. Does the report name Selank (not Semax)? The two are shipped side by side and swapped labels happen. Some laboratories add mass spectrometry; others do not.
4. Does the supplier ship from EU stock, tracked, in a few days?
5. Does the page describe the product only (composition, purity, storage) with "research use only" stated plainly? A supplier that publishes usage content is a supplier that is easy to shut down; that risk transfers to any order in transit.
6. Is the price read per mg, size by size? It is the fairest way to compare two listings of the same compound.

The wider checklist (payment, packaging, what to do if a parcel is stopped) is in where to buy research peptides in Europe. The seven checks that can be run on a product page before paying are in how to check a peptide supplier.

Further reading: MOTS-c buying guide.

The price of research Selank depends on the size of the vial and where it ships from.

The catalog table at the top of this page shows the current price per vial and per milligram for each size; the 10 mg vial has the lower cost per milligram.

What the price includes at OXpeptides: a sealed, labeled vial and the lyophilized compound inside, named with its net quantity in mg on the label. Ships from the EU · tracked: €9.90, free from €120.

See Selank in the catalog →