Is more than the labelled amount in the vial a good sign or a bad one?

On its own, neither. What makes it a good sign here is that it was measured by a named laboratory and published, rather than claimed. An overfill also has a mundane explanation: fill processes target slightly above label to ensure no vial comes in under. The publishing is the signal, not the overfill.

Should I expect 12.29 mg in the vial I receive?

No. That figure belongs to lot 29-01260229 and nothing more. Fill weights vary between batches and no vendor has guaranteed it. Use it as evidence about the vendor's documentation practice, not as an entitlement.

What does 99.32% purity leave behind?

On this lot, 0.68% of the detected UV area, appearing as a single minor peak. In peptide synthesis that residue is typically truncated sequences and side products. It is a good result by the standards of this market, and it is a purity result rather than a safety result.

Why does the mass spectrometry number matter?

Because purity tells you how uniform the powder is, not what it is. A batch could be 99% pure and be the wrong peptide. Matching a measured 751.47 Da against an expected 751.43 Da for Thr-Lys-Pro-Arg-Pro-Gly-Pro is the check that the molecule is the one named on the label.

What should I ask a seller before buying?

Whether there is an endotoxin or LAL result for the lot being shipped, and whether the certificate matches that lot rather than an older one. Both are answerable in a sentence, and an evasive answer is itself an answer.

Are the nasal spray listings the same thing?

Different format, generally thinner documentation. A spray is already in solution, which makes sterility more relevant and is usually accompanied by less published testing rather than more. Our page on [Selank nasal spray](/selank/buy-selank-nasal-spray/) covers what changes.

Selank for Sale: The Vial Held 12.29 mg of a 10 mg Label

Summary: A real listing publishes numbers that could embarrass it. This page reads one line by line, including an assayed fill weight of 12.29 mg against a 10 mg label, and names what is still missing.

This content is for informational purposes only and is not medical advice. Always consult a qualified healthcare provider before starting, changing, or stopping any medication.

Selank for sale listings mostly say the same eight words and differ entirely in what they leave out. The fastest way to tell a real one from a repackager is not the design of the page or the confidence of the copy, it is whether the seller has published a number that could have gone against it.

The listing worked through below is this one, so you can follow along with the document open.

Where readers actually buy it

Ascension Peptides — Selank

Research-grade Selank, tested by two outside labs and shipped from the US. The code below takes half off the vial.

Code at checkoutPEPTIDEDECK50% off

Selank · 10 mg$47.50$23.75$2.38/mgGet the 10 mg →

The published certificate for lot 29-01260229 assays this vial at 12.29 mg against a 10 mg label, and reports no endotoxin or sterility testing. Buying 3, 5 or 10 takes 3%, 5% or 10% off the list price. Free shipping starts at $250.

Batch certificates from two independent labs
Free shipping over $250
Ships same day if ordered before 2pm CST

Sold for laboratory research only and not for human consumption. These are affiliate links: we may earn a commission at no cost to you, and it does not change what we recommend. Prices checked August 21, 2026.

What is in the vial, in plain terms

Selank is a synthetic heptapeptide: seven amino acids, Thr-Lys-Pro-Arg-Pro-Gly-Pro, PubChem CID 11765600, formula C33H57N11O9, molecular weight 751.9 ^[3]. The first four residues are tuftsin, an immune peptide the body makes; the Pro-Gly-Pro tail is a synthetic addition that slows enzymatic breakdown. It was developed in Russia, where it holds a registration as an anxiolytic, and it is approved nowhere in the West.

For readers who arrived from our GLP-1 pages, the useful framing is that this is not adjacent to semaglutide or tirzepatide in any pharmacological sense. No incretin activity, no effect on gastric emptying, no weight-loss indication. And no trial record of the kind those medications have. What is sold on these listings is a research chemical, and it is labelled that way by the sellers who are being straight with you.

Selank for sale: what a real listing states and a thin one omits

Line item	What a real listing gives you	What a thin listing does instead
Form	Lyophilised powder, stated explicitly	Says "Selank" and lets you assume
Quantity	Milligrams per vial on the label, and ideally an independent assay of what is actually in it	Names a milligram figure with nothing behind it
Lot number	Printed on the listing and matching the certificate PDF	A generic certificate with no lot, or a lot that matches nothing
Purity method	HPLC with the chromatogram and peak list shown	"99%+ purity" as a graphic
Identity	Mass spectrometry against the expected 751.43 Da monoisotopic mass	Silence, or the word "verified"
Testing scope	Says which tests were run and, by omission, which were not	Implies a full panel with the word "tested"
Storage	Handling and storage conditions for the lyophilised powder	Nothing, or advice that contradicts the format
Legal framing	Research use only, no human-use claims anywhere	Dosing suggestions and benefit claims in consumer language

The row that separates the market is quantity. Almost every seller prints a label weight. Very few publish an independent measurement of what a vial actually contains, because the measurement can come out low and then it is on the internet permanently.

The number this page is named after

Open the certificate for the listing above ^[1]. It covers lot 29-01260229, analysis date 2026-02-07, issued by MZ Biolabs, a named laboratory at an address in Tucson, Arizona, and signed by an analytical chemist.

Three results sit at the top:

Purity 99.32% by HPLC-UV. The chromatogram is printed rather than summarised, with a peak list showing two detected peaks: the main peak at 7.13 minutes carrying 99.32% of the area, and a minor one at 6.36 minutes at 0.68%.
Identity by mass spectrometry. Expected monoisotopic mass 751.43 Da, measured 751.47 Da. The recorded spectrum shows the doubly charged ion at m/z 376.734 and the singly charged at 752.457, which is what this molecule should look like.
Measured quantity 12.29 mg per vial, against a label that says 10 mg.

That last figure is the interesting one. The vial is overfilled by roughly 23%, and the vendor published it.

Compare that to the standard listing claim, which is a purity percentage with no chromatogram, no lot, no mass and no laboratory name. Those four absences are the difference between a document and a graphic.

What the certificate does not cover, which is the point

Having credited the listing, here is where it stops.

There is no endotoxin test on that February certificate. No LAL assay, no pyrogen result, no sterility screen, no bioburden figure. We searched the document rather than assuming. Purity and identity tell you what the powder is. They tell you nothing about bacterial pyrogen load, because that is a separate assay that was not run.

This is not a pedantic gap. It is precisely the thing FDA put on record about this compound. The agency's stated position is that compounded drugs containing selank acetate "may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation and peptide-related impurities", and that it "lacks important information regarding any safety issues raised by selank acetate administered to humans" ^[2].

Immunogenicity means the immune system reacting to what it has been given. Aggregation means peptide molecules clumping into larger assemblies that look foreign. Peptide-related impurities means the truncated and side-modified sequences left over from synthesis, which is exactly what that 0.68% minor peak represents in aggregate terms. A high purity figure limits the second problem. Neither figure addresses pyrogens.

The regulatory line most listings get wrong

Sellers occasionally reassure buyers by describing Selank's regulatory position, and they are usually working from stale information.

Selank appears on no current FDA 503A bulks category list. Not Category 1, not 2, not 3. Check the lists updated May 14, 2026 and the word is absent ^[4]. What exists instead is an entry on FDA's separate list of substances "nominated but withdrawn", which the agency describes as substances "previously in category 2 of the interim policies" that "were withdrawn by the nominators" ^[2].

So a listing telling you Selank is Category 2 is quoting something that was once true. A listing telling you it is FDA approved is simply wrong; there is no approved Selank product for any indication anywhere in the West. And a listing implying that being on no list means it has been cleared has the logic backwards. Not listed means not assessed.

What the price should look like

The vial above lists at $47.50, down from $60.00, and the code PEPTIDEDECK halves it to $23.75, which is $2.38 per milligram on the label weight. Buying 3, 5 or 10 takes 3%, 5% or 10% off the list price as a separate mechanism from the code, and free shipping starts at $250, which one discounted vial does not approach.

A listing far below that range is not necessarily fraudulent, but the cost of running HPLC, mass spectrometry and quantification on every batch has to come from somewhere. If a seller is materially cheaper and publishes no lot-specific certificate, you have found where the saving came from. The same reasoning applies across this market, and we ran it in more detail on what BPC-157 costs and why.

For the way listings differ by structure rather than by document, what MOTS-c listings are really selling covers similar ground on a compound with a comparable supply picture, and the grade problem on NAD+ listings is the clearest example on this site of a product where identity and purity both pass and the material is still wrong.

Questions buyers ask about these listings

Is more than the labelled amount in the vial a good sign or a bad one?: On its own, neither. What makes it a good sign here is that it was measured by a named laboratory and published, rather than claimed. An overfill also has a mundane explanation: fill processes target slightly above label to ensure no vial comes in under. The publishing is the signal, not the overfill.
Should I expect 12.29 mg in the vial I receive?: No. That figure belongs to lot 29-01260229 and nothing more. Fill weights vary between batches and no vendor has guaranteed it. Use it as evidence about the vendor's documentation practice, not as an entitlement.
What does 99.32% purity leave behind?: On this lot, 0.68% of the detected UV area, appearing as a single minor peak. In peptide synthesis that residue is typically truncated sequences and side products. It is a good result by the standards of this market, and it is a purity result rather than a safety result.
Why does the mass spectrometry number matter?: Because purity tells you how uniform the powder is, not what it is. A batch could be 99% pure and be the wrong peptide. Matching a measured 751.47 Da against an expected 751.43 Da for Thr-Lys-Pro-Arg-Pro-Gly-Pro is the check that the molecule is the one named on the label.
What should I ask a seller before buying?: Whether there is an endotoxin or LAL result for the lot being shipped, and whether the certificate matches that lot rather than an older one. Both are answerable in a sentence, and an evasive answer is itself an answer.
Are the nasal spray listings the same thing?: Different format, generally thinner documentation. A spray is already in solution, which makes sterility more relevant and is usually accompanied by less published testing rather than more. Our page on [Selank nasal spray](/selank/buy-selank-nasal-spray/) covers what changes.

Selank for sale rewards a habit rather than an expertise: open the certificate, find the lot number, and check whether the seller published anything that a less careful company would have kept quiet. On the February document above the answer is a measured 12.29 mg against a 10 mg label, which is genuinely to its credit, and a missing endotoxin line that the June batch does supply.