Name: Selank 10mg (Research Peptide)
Brand: Verum Peptides
Price: 59 USD
Availability: InStock

Identification

Chemical name	L-threonyl-L-lysyl-L-prolyl-L-arginyl-L-prolyl-glycyl-L-proline
Common designation	Selank
Sequence	Thr-Lys-Pro-Arg-Pro-Gly-Pro
One-letter	TKPRPGP
Length	7 amino acids, linear, free termini
Construction	The first four residues are tuftsin, a naturally occurring tetrapeptide fragment of immunoglobulin G. The remaining three are a proline-glycine-proline extension added to the C-terminus. See section 03.
Molecular formula	C33H57N11O9
Molecular weight	751.9 g/mol
Expected ions	[M+H]+ near 753; [M+2H]2+ near 377. Not measured on this lot; see section 04.
CAS number	129954-34-3
Proline content	Three of seven residues are proline, which constrains backbone conformation and resists several common peptidases
Oxidation-sensitive residues	None. The sequence contains no methionine, cysteine, tryptophan or tyrosine.
Physical form	White lyophilized powder
Quantity supplied	10 mg nominal per unit
Country of manufacture	United States

Certificate of analysis - current lot

The interactive verification record is shown below, followed by the same information reproduced as text on this page and the full certificate as a document. The record does not depend on the embed loading.

Certificate of analysis - batch S91YKX

Batch record

S91YKX

Testing laboratory	Accurate Test Labs, Fort Lauderdale, Florida. Independent third party, not owned by or affiliated with Verum.
Sample received	24 July 2026
Analysis completed	27 July 2026
Sample and laboratory reference	2607AFL1207.4224 · ATL-38023
Method	TM-13, document COA-12 Peptides Rev. 1

Results, this batch

Purity	99.607 %, reported as a total purity of 99.61 %
Content	13.52 mg per unit
Mass confirmation	Not reported by this laboratory. See section 04.
Bacterial endotoxin	Not tested on this batch
Microbial analysis	Not tested on this batch

Purity and content figures above are specific to batch S91YKX and are not specifications carried across other batches. The measured content of 13.52 mg sits well above the 10 mg nominal, which is the direction an overfill should run, and it is a figure most suppliers in this category do not measure at all.

A natural tetrapeptide with three residues bolted on

This molecule is not a single designed sequence. The first four residues are tuftsin, a naturally occurring tetrapeptide released from the heavy chain of immunoglobulin G and characterised in its own right since the 1970s. The last three, proline-glycine-proline, are a synthetic extension.

The extension is not decorative. Free tuftsin is cleaved rapidly by aminopeptidases, and the added prolines constrain the backbone in a way that resists several of those enzymes. The design intent, in other words, was to keep a known natural sequence intact for longer rather than to create a new pharmacophore.

For experimental design that matters more than it sounds. Any observation from this compound may be attributable to the tuftsin core, to the intact heptapeptide, or to fragments generated as the extension is trimmed. Those are three different candidate species, and a design that does not include free tuftsin as a comparator is leaving the most obvious alternative explanation untested.

This certificate carries no mass spectrometry

Several certificates in this catalogue publish a mass confirmation alongside the purity figure. This one does not. The laboratory that released this batch reports purity and content per unit, and does not print a mass spectrum on the face of the document.

That is worth understanding rather than glossing. A purity figure describes how much of what eluted was one peak. It does not, on its own, establish the molecular weight of that peak. On a seven-residue sequence built from a four-residue natural core, the species most worth excluding are precisely the ones a chromatographic method may not separate cleanly: the free tetrapeptide, and truncations that have lost part of the extension.

We state this rather than let a high percentage stand in for a confirmation it does not provide. Where molecular weight confirmation is material to your work, request it before ordering or source material released against it. For reference, the intact heptapeptide gives a protonated ion near 753.

Testing scope

Panels differ between products and between lots. What follows is the scope of testing performed on this batch. Nothing is claimed unless it appears on the certificate for the batch supplied.

Performed

✓	Purity, reported per analyte and as a total
✓	Content in mg per unit

Not performed

-	Mass spectrometry confirmation
-	Discrimination from the free tuftsin core
-	Bacterial endotoxin
-	Sterility and microbial enumeration
-	Counterion identity and content
-	Elemental impurities, residual solvents

This is the narrowest panel in the catalogue and it is presented as such. Where a parameter is material to intended laboratory work, purchasers should verify it independently or source material released against that specification.

Storage and laboratory handling

Lyophilized powder, transit	Stable at ambient temperature during shipping and short-term handling. Cold-chain transport is not required.
Lyophilized powder, storage	−20 °C, protected from light, container tightly closed
Solubility	Freely soluble in sterile laboratory-grade water or a defined aqueous buffer appropriate to the assay
Solution, storage	2 °C to 8 °C, protected from light. Materially less stable than the dry powder.
Freeze-thaw	Avoid repeated cycles.
Sequence-specific note	No oxidation-sensitive residues, so this sequence carries none of the liabilities governing handling for many peptides, and three prolines make the backbone unusually resistant to enzymatic cleavage. Both are genuine advantages and both are frequently overread: resistance to peptidases is not stability in aqueous storage, and this peptide hydrolyses in solution like any other. It is hygroscopic; allow the container to reach room temperature before opening.
Personal protection	Handle under standard laboratory conditions with gloves, eye protection and a laboratory coat.

Preparation conditions are the responsibility of the receiving laboratory. Verum provides no protocol, no preparation instruction, and no guidance on use.

Published literature

This page carries no bibliography. We list references only where we can link them directly, so a reader can check the source rather than take our description of it, and we are not able to do that reliably for this compound. A summary of work we cannot point you to would be an assertion rather than a citation, and we would rather leave the section empty than fill it with one. Researchers should search the primary record themselves.

Regulatory status

United States	Not approved by the FDA for any indication. Not on the section 503A bulk drug substances list.
Advisory committee	This substance has not been reviewed by the Pharmacy Compounding Advisory Committee and is not scheduled at either announced meeting. It therefore has no committee recommendation either for or against.
European Union and United Kingdom	No marketing authorisation.
Status date	Accurate as of August 2026. Verify the current position independently.

Purchase eligibility

By placing an order you confirm each of the following:

✓	You are at least 21 years of age.
✓	You are a qualified researcher, or are purchasing on behalf of a research institution or commercial laboratory.
✓	The material will be used solely for in vitro laboratory research.
✓	The material will not be administered to humans or to animals, and will not be resold or transferred for any such purpose.
✓	You are responsible for compliance with all federal, state and local law governing receipt, handling, storage and use.

Confirmation is recorded at checkout against your order. Verum reserves the right to decline or cancel any order.

Supply

Orders placed before the daily cutoff are dispatched the same day from our United States warehouse. Domestic orders typically arrive within two business days. A tracking reference is issued by email once the consignment leaves the facility. Each unit carries a scannable code linking to the certificate for its own batch.

Not for human or veterinary use. Not for use in diagnostic or therapeutic procedures. This product is a laboratory reagent. Nothing on this page constitutes medical advice, a recommendation for personal use, or a representation that this material is safe or effective for any purpose. No statement here has been evaluated by the U.S. Food and Drug Administration.