Foundational guide
Best Selank Source: Test Coverage Outweighs Purity
The weighting is published before the result and it deliberately demotes the number every storefront leads with. Forty-five of the hundred points ride on two tests that most certificates in this market never run, and the rubric is then applied to two documents from the same vendor to show what it is really measuring.
Any ranking of the best Selank source is worth reading only if the scoring rule was fixed before the entries were examined, so the rule comes first and the result comes second. One hundred points across six documentary criteria, none of which depends on reputation, reviews, storefront design or how long a seller has been trading.
The weighting is deliberately unbalanced. Forty-five of the hundred points sit on two tests that most certificates in this market do not run, and only twenty sit on the purity figure that every listing leads with. The justification is set out below before any entry is scored, so that a reader who disagrees can disagree with the rule rather than with the conclusion.
Supplier publishing lot-level data
Selank, Ascension Peptides
Every lot carries certificates from two independent laboratories. The code below halves the listed price on the vial.
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.
- Kovera Labs and MZ Biolabs certificates per lot
- Carriage free above $250
- Dispatched same day before 2pm CST
Supplied for laboratory research use and not for human consumption. Affiliate links: a commission may be earned at no cost to the reader, and it does not affect the assessment above. Prices verified August 21, 2026.
The rubric for the best Selank source, published before the ranking
| Criterion | Points | Why this weight |
|---|---|---|
| Bacterial endotoxin result on the lot | 30 | Cannot be inferred from any other line, absent from most documents, and addresses the hazard the regulator named |
| Sterility or microbial screen on the lot | 15 | Same argument, one step weaker, because a rapid screen is not a compendial sterility test |
| Identity by mass spectrometry, values stated and spectrum shown | 20 | Checkable by any reader against a published monoisotopic mass, and worthless if merely asserted |
| Purity by HPLC, with chromatogram and peak list | 20 | Important, near-universal, and partly reconstructable by the reader when the integration is printed |
| Assayed quantity against the labelled mass | 10 | Rare, falsifiable, and the only line that can publicly embarrass the seller |
| Named laboratory and lot traceability | 5 | Low points because it functions as a gate: score zero here and the other ninety-five describe nothing you can hold |
The case for the top weighting is FDA’s own. Its safety risks page states 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 the agency lacks important information regarding any safety issues raised by selank acetate administered to humans. That is a testing question rather than a matter of opinion, and it is not answered anywhere on a purity line. Our companion piece on why sterility is not a purity figure sets out why the two categories cannot substitute for each other, and our weighted ranking for a different compound reached a similar conclusion by a similar route.
What the rubric deliberately leaves out
Four things that appear in most vendor comparisons carry no points here, and saying why is part of publishing the rule.
- Price. A per-milligram figure is arithmetic on a label, and it can be computed independently of anything on a certificate. Folding it into a quality score lets a discount buy a better rating, which is precisely the confusion this exercise exists to prevent.
- Dispatch speed and shipping terms. Real operational facts, worth knowing, and unrelated to whether anyone can demonstrate what is in the vial. Domestic stock earns its keep by making a lot number available before dispatch rather than by arriving sooner.
- Reviews and testimonials. Unverifiable at the point of reading, trivial to manufacture, and describing an experience rather than a measurement.
- How long a seller has traded. Longevity is a survival statistic. It correlates with nothing on a certificate, and treating it as evidence rewards incumbency.
The rubric applied to two documents from one vendor
Before ranking categories, it is worth demonstrating that the rubric measures what it claims to. The vendor disclosed above publishes a February and a June certificate for each of Selank and Semax, the two Russian nootropic heptapeptides, and the two analysis windows score very differently. The pair below takes the February document from one compound and the June document from the other, because the same split exists on both. If the rubric were secretly grading vendors, that could not happen.
| Criterion | Selank, February lot 29-01260229 | Semax, June batch 30-05260628 |
|---|---|---|
| Endotoxin, 30 | 0, no result anywhere in the document | 30, kinetic assay to USP Chapter 85, below 0.20 EU/mL against a 0.5 limit across a 2.0 mL dilution volume, so below 0.40 EU per vial |
| Sterility, 15 | 0, no screen | 12, rapid screen, no growth, not full USP Chapter 71 |
| Identity, 20 | 20, 751.43 expected against 751.47 measured, spectrum printed | 8, confirmed by LC-MS, no masses stated, no spectrum |
| Purity, 20 | 20, 99.32 percent with peak list and chromatogram | 14, 99.886 percent against a spec, chromatogram, no peak list |
| Quantity, 10 | 10, 12.29 mg on a 10 mg label | 10, 11.23 mg on a 10 mg label |
| Traceability, 5 | 5, MZ Biolabs, lot and analyst named | 5, Kovera Labs, report number and access code |
| Total | 55 | 79 |
Neither document is a superset of the other, which is the finding worth carrying away. The June report adds the microbiological panel and a heavy metals screen and loses ground on identity and purity evidence. The February one shows its analytical working in detail and runs no microbiology at all. That split is the same on both compounds, so which panel you get is a batch question rather than a product question, and the practical move is to read every certificate shown on a product page rather than only the one that is a clickable link. A perfect certificate would be the union of the two, and every element of it already exists in this vendor’s published output, just never on one page. The full read of the February Selank document is in our six-test assessment of the published lot.
The ranking, in categories rather than brand names
Entries are categories of supplier, because a category can be scored on what it is structurally able to produce while a brand name can change behaviour between lots. The indicative ranges assume a supplier performing typically for its category.
Suppliers publishing a lot-matched report covering both panels
Indicative 85 to 100. Identity, purity and quantity on the analytical side, endotoxin and a microbial screen on the other, all tied to one lot number that will appear on the vial. The vendor disclosed above reaches this category on its June Selank batch 29-05260628, certified by Kovera on 2 June 2026, which pairs purity, net content and LC-MS identity with an endotoxin result and a rapid sterility screen. Its February lot does not, which is the point: the category a supplier occupies is decided by the batch in front of you.
Suppliers publishing a lot-matched analytical report with the raw traces
Indicative 50 to 60, and this is where the vendor disclosed on this page sits for Selank at 55. Everything an analytical chemist would want on identity, purity and quantity, with the chromatogram, the peak list and the mass spectrum all printed rather than summarised, and nothing at all on the microbiological side. The practical move for a buyer in this category is to ask whether a newer combined report exists for the lot that will ship.
Suppliers publishing a lot-matched summary certificate with no traces
Indicative 30 to 40. A lot number, an analysis date, and a table of figures with no underlying data. The figures may be perfectly accurate. They are simply unverifiable by the reader, which converts every number into a claim requiring trust. This is the most populous category in the research peptide market.
Suppliers publishing a product line document not tied to a lot
Indicative 0 to 10, scoring only on the gate criterion and often not even that. A real measurement performed on real material with no traceable relationship to the container in transit is a weaker piece of evidence than it appears, because the link that would make it about your purchase is exactly the link that is missing.
Sellers publishing no analysis, or somebody else’s
Zero. Included because it is a large share of the market, particularly among resellers and group buys where a certificate from an upstream supplier is presented for repackaged material. A document produced for someone else’s vial is not evidence about yours, and presenting it as though it were is the most common misrepresentation in this channel.
Sensitivity: what happens if you disagree with the weighting
A weighted score is an argument, and the honest way to present one is to show what happens when the argument is rejected. Suppose a reader considers the microbiological panel largely irrelevant to their use and rebuilds the rubric accordingly: endotoxin 5, sterility 5, identity 30, purity 30, quantity 20, traceability 10.
On that rubric the February certificate scores 90 and the June one scores 72, which reverses the earlier result completely. Nothing about either document changed. The entire difference is the weighting, and a reader who prefers the second rubric should prefer the second answer. What cannot be done honestly is to adopt one weighting and quote the other one’s conclusion.
Two things are worth saying about which rubric to prefer. The first is that the answer depends entirely on what the material is for, and that is a question about the reader rather than about the supplier. The second is that the criteria which are already near-universal cannot separate suppliers, so a rubric weighted toward them will always produce a flatter and less useful ranking. Our note on which suppliers commission a second independent laboratory works the same problem from a different direction.
What a score of any size does not establish
The rubric answers one question: can this supplier demonstrate what is in a vial. It does not touch the second question, which is whether the compound does anything worth having, and a supplier scoring one hundred would move that question by nothing at all.
On the second question the record is thinner than the market implies. Selank is a seven-residue tuftsin analogue developed at the Institute of Molecular Genetics in Russia, catalogued in PubChem as CID 11765600, and registered in Russia as an anxiolytic. That is a national registration decision rather than an FDA approval, and no regulator in the United States or Europe has assessed it for any indication. The English-language literature is dominated by animal and cell work, such as the 2014 Molecular Immunology study of inflammation-related gene expression under the tuftsin analogue, and a search of ClinicalTrials.gov returns no registered study with Selank as an intervention. Keep the documentary question and the pharmacological one in separate columns, because everything above belongs firmly in the first.
Frequently asked questions
- Why does endotoxin carry more weight than purity in this rubric?
- Because of what each number can and cannot substitute for. Purity is reported by nearly every serious supplier, lands in the high nineties almost universally, and can be partly reconstructed by a reader from a printed peak list. A bacterial endotoxin result cannot be inferred from anything else on a certificate, is absent from most documents in this market, and addresses the specific hazard FDA named for this substance when it described a risk of immunogenicity for certain routes of administration arising from aggregation and peptide-related impurities. A criterion that discriminates between suppliers and cannot be reconstructed is worth more points than one that does neither.
- Does a low score mean the material is bad?
- No, and the rubric is built so that it cannot mean that. A score here measures how much of the analytical dossier a supplier makes available and traceable. Material quality is a separate question that cannot be answered from a browser, and conflating the two is the error this whole exercise exists to avoid. The most a high score establishes is that a supplier has made itself checkable.
- Which source scored highest?
- The category that publishes a lot-matched report covering both the analytical and the microbiological panel. The vendor disclosed on this page reaches it on its June Selank batch 29-05260628 but not on its February lot 29-01260229, which scores 55 out of 100 and sits in the second category. Its June Semax report scores 79 on the identical rubric. That gap between two analysis windows from one seller is the clearest available demonstration that the rubric grades paperwork rather than peptide, and that the panel you get is set by the batch rather than by the product.
- Is the newest certificate always the best one?
- Not on this evidence, and the comparison here is a useful corrective. The newer June report adds a bacterial endotoxin assay, a heavy metals screen and a sterility screen, all of which the February document lacks. It is also weaker on identity, confirming the compound by LC-MS without stating an expected or measured mass or printing a spectrum, and weaker on purity, giving a figure against a specification without an integration table. Newer means a different panel, not a superset.
- What would a perfect Selank certificate contain?
- The union of the two documents discussed here, on one lot: identity stated as an expected and a measured monoisotopic mass with the spectrum printed, purity as a figure with the peak list and chromatogram behind it, an assayed quantity against the labelled mass, a bacterial endotoxin result against a stated acceptance limit, a sterility or microbial screen, and a named laboratory with a lot number that will appear on the vial. Every element of that already exists in this vendor's published output, split between its February and its June certificates. No single document, for either compound, currently carries all of it, which is why the page is worth reading in full rather than the linked PDF alone.
Limitations of the evidence
This rubric scores documents, not material, and the distinction is the point rather than a caveat. A supplier can publish an excellent certificate for a lot that behaves badly, and a supplier publishing nothing may hold perfectly good material; neither possibility is detectable from outside a laboratory, and this exercise does not attempt it. The entries ranked are categories of supplier rather than named companies, except where a document can be quoted precisely. Scores awarded to the two certificates discussed are our judgements applied to a rubric we wrote, and a reader who weights the criteria differently will get a different answer, which is why the sensitivity analysis is included. All figures belong to specific lots on specific analysis dates and do not describe material shipped later. We have not commissioned analysis, tested any vial or audited a supplier, and nothing here establishes that Selank is safe or effective in humans.
References
Citations are annotated with an evidence tier reflecting study design and replication. See Methodology for criteria.
- 1.MZ Biolabs, for Ascension Peptides · Certificate of Analysis, Selank 10 mg, lot 29-01260229, analysis date 2026-02-07, HPLC-UV-MS · 2026Validated
- 2.Kovera Labs, for Ascension Peptides · Certificate of Analysis KVR-2026-E848E0, Semax 10 mg, batch 30-05260628, with bacterial endotoxin analysis, heavy metals screening and rapid sterility screen · 2026Validated
- 3.U.S. Food and Drug Administration · Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, content current as of 04/22/2026 · 2026Validated
- 4.U.S. Food and Drug Administration · Pyrogen and Endotoxins Testing: Questions and Answers, Guidance for Industry · 2026Validated
- 5.National Center for Biotechnology Information · PubChem Compound Summary for CID 11765600, Selank · PubChem · 2026Validated
- 6.Kolomin T, Morozova M, Volkova A, Shadrina M, et al. · The temporary dynamics of inflammation-related genes expression under tuftsin analog Selank action · Molecular Immunology · 2014PMID 24291245DOI 10.1016/j.molimm.2013.11.002Preclinical