Where to buy Selank Peptide: sizes, price per mg and how to verify the lot

What "selank peptide" names, and what it does not

Selank is Thr-Lys-Pro-Arg-Pro-Gly-Pro, written TKPRPGP: the natural tetrapeptide tuftsin (TKPR) with a Pro-Gly-Pro extension added to slow its breakdown. Formula C33H57N11O9, average mass 751.9 Da, PubChem CID 11765600. It was developed at the Institute of Molecular Genetics in Moscow, which also produced Semax, and the papers cited at the foot of this page come from that research tradition. Listings write Selank, Selank acetate, selank peptide and the developer code TP-7; those are one molecule. NA-Selank, with an N-terminal acetyl group, is a different one, 42 Da heavier.

The evidence base is smaller and more geographically concentrated than commercial writing implies, and this page makes no claim about what the peptide does. What it can state exactly is the chemistry: seven residues with a lysine and an arginine, so the peptide is basic and holds two counter-ions; three prolines, which make the chain rigid and its deletion products distinctive; and no residue that oxidises, which makes it a stable lot to keep.

The buying problems follow from that. Two counter-ions on a 752 Da peptide mean the salt form moves net content by more than a tenth; the acetyl variant shares the name in listings and differs by 42 Da; and a missing proline, 97 Da light, is the deletion to look for. All three are visible on a certificate that prints its numbers, and invisible on one that prints a percentage and the word conforms, which is the more common kind for this compound.

The reference point for identity is public. PubChem lists Selank as CID 11765600 with molecular formula C33H57N11O9, an average molecular weight of 751.9 Da and a monoisotopic mass of 751.434 Da. Those are the numbers a mass spectrometer is checked against, and the number a certificate must print beside the observed mass.

In plain terms: A man-made peptide seven building blocks long, based on an immune peptide called tuftsin. No approved product in the United States and no official standard. The evidence base is smaller and more geographically concentrated than commercial writing implies.

Selank for sale: sizes and price per mg

LabFirst lists Selank in 2 sizes (5mg, 10mg) from $39 to $44, priced per vial with the per-mg figure beside it so sizes can be compared without arithmetic. Per mg, the 10mg vial is the cheapest at $4.40 and the 5mg the dearest at $7.80, which is the usual shape: the vial, stopper, seal, fill and laboratory run cost the same whatever mass goes in.

The volume tiers are per size, not per basket: ten vials of one size take 10% off that line and twenty take 15%, and mixed sizes do not combine. Shipping is a flat $15 on orders under $200 and free from $200, within the United States only, with same-day dispatch on orders placed before 12 PM Pacific on a business day. The cost per mg tool runs the same comparison across any two listings, ours or anyone else's.

Seven ordinary residues make Selank an inexpensive synthesis, and the vial, the fill and the laboratory run are most of the price; the 10 mg vial costs only a little more than the 5 mg and the per-milligram figure nearly halves between them. A laboratory that will use the material buys the 10 mg vial; one qualifying a lot buys the 5 mg vial once and reads the mass, the salt and the net content on its certificate.

The price signal is the salt and the variant. A trifluoroacetate lot holds noticeably less peptide per milligram than an acetate lot of the same label, and NA-Selank sold as Selank is a different compound at whatever price. Compare per milligram of peptide from the net content line, with the observed mass beside it. The only discounts on this page are the volume tiers, per size and unchanged month to month, and the lot on the vial is whatever the certificate index says on the day.

The certificate a Selank lot must carry

Three tests answer three different questions, and a certificate of analysis for Selank is only complete when it carries all three for the exact lot on the vial. Identity is settled by mass spectrometry, and the number to look for on a Selank certificate is 751.434 Da monoisotopic (or 751.9 Da average, if the laboratory reports the deconvoluted average mass). The observed mass should sit within the instrument's stated tolerance of that figure, and the certificate should print both the theoretical and the observed value, not just a tick.

Purity is a separate question, answered by HPLC: how much of what came off the column was the compound. The figure is only interpretable with its method beside it (column, gradient, detection wavelength) and a date, which is what ICH Q2(R2) means when it asks that an analytical procedure be shown fit for its purpose. A percentage with no method and no date is a number somebody typed, and a certificate that carries every test but for a different lot number than the vial is the most common failure of all and the easiest to catch. Net content is the third test and the one most often missing: the milligrams of Selank actually in the vial, measured, against the size printed on the label.

Identity is the observed mass against 751.434 Da monoisotopic (751.9 Da average), seen in electrospray as m/z 752.4 for the singly charged ion and 376.7 for the doubly charged, with both theoretical and observed values printed. A mass near 794 Da is NA-Selank, the acetylated variant, which some sellers ship under the plain name; a mass near 654 Da is a des-proline deletion. Neither is Selank, and a certificate that reads "conforms" without a number cannot tell you which of the three the vial holds.

Purity by HPLC on a basic proline-rich heptapeptide should show the chromatogram with its column, gradient and wavelength; with no aromatic residue the peptide is read at 210 to 220 nm, where the peptide bond absorbs, and a certificate that quotes a 280 nm purity for Selank has measured something else. Net content is the line that pays: Selank is sold as the acetate, or from some factories the trifluoroacetate, and with two basic residues the salt is a large share of the powder. Quantitative HPLC against a standard or amino acid analysis tells you what the labelled milligrams are made of.

Where to buy Selank: five checks before you order from anyone

Every seller of selank peptide says "third-party tested". The phrase costs nothing. These five checks take about four minutes per listing and separate a tested lot from a tested-sounding one.

1. The lot on the vial is the lot on the certificate. Read the printed lot number, then open the certificate and match it. A certificate for "Selank" with no lot, or a lot that does not match, describes some other vial.
2. The laboratory is named and has its own lookup. The report should come from a laboratory the seller does not own, with a search code you can enter on the laboratory's own site. LabFirst lots are tested by Freedom Diagnostics and looked up by accession number; anything that can only be verified on the seller's own page has not been verified.
3. The theoretical mass is printed, and it is the right one. For Selank that is 751.434 Da monoisotopic; a certificate that prints a different figure has either measured a different molecule or copied a template.
4. Purity has a method and a date. An HPLC percentage should name the method and the run date. A figure that reads "99%+" with neither, or one date reused across every product a seller lists, is decoration.
5. Net content is stated in milligrams. The label size is a claim; the certificate's net content is the measurement. If the certificate has no net content line, the purity figure describes the powder, not the vial, and the price per mg you calculated is fiction.

How listings for Selank specifically mislead:

• NA-Selank shipped as Selank, or the reverse. The acetylated variant is 42 Da heavier and a different compound; only the observed mass on the certificate tells them apart.
• A purity figure read at 280 nm. Selank has no aromatic residue and barely absorbs there; a real Selank chromatogram is run at 210 to 220 nm, and a 280 nm figure describes something else.
• A 10 mg label with no salt form and no net content. Two basic residues hold two counter-ions; the difference between acetate and trifluoroacetate is more than a tenth of the peptide content.
• "Approved medicine" copy without the geography. Selank is registered in Russia and approved nowhere else; the FDA placed Selank acetate in Category 2 of its 503A list in September 2023.

How to verify a LabFirst Selank lot

The Selank sizes in stock today carry lot LF-2608-22. Lot LF-2608-22 is at Freedom Diagnostics on accession FD-2026-05716 for identity, purity and net content. Until the report is attached the product page says "pending verification" against that lot and makes no purity claim; the price stands and the report goes live the day it arrives, on the page, at /coa/, and inside the receipt and packing slip for every order of that lot.

Verification runs through the laboratory, not through us. Open the certificate index, find the lot, and use the accession number on the Freedom Diagnostics lookup page; the report you see there is the laboratory's copy, not ours. Each lot also carries a Finnrick verify link, and every receipt and packing slip states that a customer may submit a sealed vial to Finnrick's free testing programme with the order as proof of purchase, so the brand's public record is built from vials we did not choose.

The product page reads the live stock feed on load (stock, lot and certificate state for every size), so what you see when you order is what ships. The lot is printed on the label and encoded in the QR patch on its right-hand side; scanning it opens that lot's record.

Storage and shipping for Selank

Selank is one of the stable peptides: no cysteine, no methionine, no tryptophan, no asparagine or glutamine, and three prolines that stiffen the chain. Lyophilised and sealed at 2 to 8 C out of light it keeps for the full shelf period on the certificate, and in solution it outlasts most of the catalogue, though a laboratory still dates its solutions and keeps its own record because stable is a comparison and not a number. Its one weakness is water: a basic peptide with two counter-ions takes moisture from humid air the moment the vial is opened, and a cake that has absorbed water no longer weighs what the label says. Open a vial once, for its purpose, and never re-seal one for storage.

Orders ship within the United States, flat $15 under $200 and free above it, same day when placed before 12 PM Pacific on a business day, and the shipping page states the cutoff, the carriers and what is and is not promised.

The record a laboratory keeps on arrival is what makes the certificate usable later, and it is short:

• the lot number as printed on the vial, and the certificate's accession or search code beside it;
• the date received and the condition of the seal;
• the storage location and temperature it went into;
• the number of vials, and later the date each one was opened and by whom.

A Selank vial with that record behind it can be traced from the bench to the laboratory report in one step; without it, the certificate is a document about a vial that can no longer be identified.

Regulatory status, and what this page is not

Selank is registered as a medicine in Russia and is not approved in the United States or by any comparable regulator; no USP or Ph. Eur. monograph defines an acceptable lot. In September 2023 the FDA placed Selank Acetate (TP-7) in Category 2 of its interim list of bulk drug substances nominated for compounding under section 503A, the category for substances it has identified as raising significant safety risks, which bars licensed pharmacies from compounding with it. That listing concerns pharmacies, not laboratory material; the Russian registration concerns a finished product in another jurisdiction, and neither transfers to a research vial.

FOR LABORATORY AND IN-VITRO RESEARCH USE ONLY. NOT FOR HUMAN OR ANIMAL CONSUMPTION. LabFirst sells Selank to laboratories and researchers as material for in-vitro work, gives no guidance on use, and ships only against that understanding. Nothing on this page or on the product page describes preparing or administering anything.

What is Selank studied for?

Published research on Selank investigates the areas below — which is a different question from what Selank will do for anyone, a claim about a living system that nothing on this site is sold for.

What it is. A man-made peptide seven building blocks long, based on an immune peptide called tuftsin.

What the research looks at. It appears in animal work coming largely from a narrow set of research groups, which is worth carrying in mind while reading it.

How it is thought to work. Built from tuftsin with a short tail added for durability. How it works is not settled in the published research.

What is not established. No approved product in the United States and no official standard. The evidence base is smaller and more geographically concentrated than commercial writing implies.

The full record, including the certificate for the lot in stock, is on the Selank product page.

Common questions

Sources

• PubChem, Selank, CID 11765600. Public record for the molecular formula (C33H57N11O9), average molecular weight (751.9 Da) and monoisotopic mass (751.434 Da) quoted here as the identity reference.
• Volkova and colleagues, Selank administration affects the expression of some genes involved in GABAergic neurotransmission, Frontiers in Pharmacology 2016. Primary description of the compound in the literature; supports the class and naming stated here, not any use.
• Kozlovskii and Danchev, The optimizing action of the synthetic peptide Selank on a conditioned active avoidance reflex in rats, Neuroscience and Behavioral Physiology 2003. Primary description of the compound in the literature; supports the class and naming stated here, not any use.
• Alliance for Pharmacy Compounding, 503A Categories Update, 29 September 2023 2023-09-29. Lists the substances the FDA moved to Category 2 on that date, including Selank Acetate (TP-7).
• ICH Q2(R2), Validation of Analytical Procedures (2023) 2023-11. Why a purity figure is only interpretable with its method, and what "fit for purpose" means for the HPLC and mass spectrometry results a certificate reports.
• Freedom Diagnostics, certificate lookup by accession number. The laboratory-side lookup a LabFirst lot is verified on; the report there is the laboratory copy, not ours.
• Finnrick, verify a vendor or lot. Independent verification page linked from every LabFirst lot; customers may submit sealed vials with their order as proof of purchase.