Selank Coupon: Half Price, and a Two-Page Certificate

The Selank coupon at the supplier linked below is PEPTIDEDECK. It takes 50 percent off the list price of the only presentation sold, so a 10 mg vial goes from $47.50 to $23.75 and the cost per labelled milligram goes from $4.75 to $2.38.

That is the whole commercial claim, and it is a good claim precisely because it can be falsified at a checkout in about fifteen seconds. The rest of this page is about the much larger set of things a working code cannot tell you, which on a peptide sold in a vial is a set worth naming.

The code, and the listing it applies to:

Applying the Selank coupon and reading the summary

Add the 10 mg listing, enter PEPTIDEDECK in the discount field, then look away from any banner and at the order summary. Five values are fixed for a single-vial order, which is what turns a feeling into a measurement.

The last row is the one people skip and the one that catches quantity errors. The full tier arithmetic, and what the assayed contents of the published lot do to that per-milligram figure, sits on our breakdown of the price per milligram.

The quantity tiers are a separate and much smaller lever

Three, five and ten vials take 3, 5 and 10 percent off the list price respectively. Set against a code that halves it, the tiers are close to noise, and the table is here so the comparison is visible rather than asserted.

Ten vials bought at the deepest tier save $47.50 across a $475.00 basket. One vial bought with the code saves $23.75 on a $47.50 order. Whether the two can be combined is not documented anywhere we could find, and an undocumented stack is not a fact, so the honest instruction is the boring one: put the basket together, apply the code and read the summary. Carriage becomes free above $250, which five vials at the tier price does not reach and ten does.

What a working code certifies about the vial

Nothing at all, and the distance between the two kinds of claim is the reason this page exists. A discount is a setting in a shop. Identity, purity, quantity and bacterial endotoxin are measurements made on a lot before it was priced, each produced by a separate method with a separate cost, and a result is only as trustworthy as the method behind it. That is the principle ICH Q2(R2) formalises for regulated analytical work, and research-supply certificates operate under no such obligation, which is why the document matters more than the headline number printed on it.

The February certificate for lot 29-01260229 is a real analysis: purity 99.32 percent by chromatography, identity confirmed by mass spectrometry at 751.47 Da against an expected 751.43, and a measured quantity of 12.29 mg in a vial labelled 10 mg. It is signed by a named chemist at a named laboratory and it shows its chromatogram. Most of this market publishes nothing of the kind.

It is also two pages long, and both omissions are on the pages that are not there.

Two pages in February, four pages in June

The same supplier publishes a second Selank certificate, for the June batch 29-05260628, and it runs to four pages. The extra two carry a kinetic chromogenic bacterial endotoxin assay performed to USP Chapter 85, reporting below 0.20 EU/mL against an acceptance limit of 0.5 across a 2.0 mL dilution volume, plus a rapid two-day sterility screen recording no growth and a heavy metals panel returning negative for arsenic, cadmium, lead and mercury. The February document carries none of those. The same February-to-June change runs across this vendor’s catalogue, Semax included, so the panel is set by the batch rather than by the product, and the way to see that is to read every certificate shown on a product page rather than only the one that is a clickable link.

Endotoxin is not a purity question and it is not an identity question. It is a separate quantitative assay, and comparisons of the available methods, such as the work by Marius and colleagues on testing in purified water matrices, exist because getting a defensible number out of one takes deliberate technique. FDA maintains its own questions and answers on pyrogen and endotoxins testing for the same reason. A document that stops before that assay has not failed it; it has not run it, and those are different states that a product page will not distinguish for you.

Why the omission matters particularly on this compound

FDA has published a safety assessment of selank acetate stating that compounded drugs containing it may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation and peptide-related impurities, and that the agency lacks important information regarding any safety issues raised by the substance administered to humans. Read analytically, that sentence names the test list a buyer should be looking for rather than expressing a general unease.

Selank is a synthetic seven-residue peptide, PubChem CID 11765600, an analogue of tuftsin with a tail added to slow enzymatic breakdown. It holds no FDA approval for any indication, and its nomination for the 503A bulks list was withdrawn rather than accepted or refused, so no compounding pathway follows from it either. In that setting the published lot document is not a marketing extra. It is the only evidence in the transaction, and the questions to ask of it are the same ones we apply when scoring a supplier in our ranking where testing scope carried most of the weight, and the same ones behind the equivalent code page for NAD+. For how this site grades material sold under research-use terms generally, see what research-use supply actually means. Nothing here describes or implies human use.