Questions, answered

Purity tells you what proportion of the material is the intended compound — but only mass spectrometry tells you the compound is what the label claims. A report showing 99% purity and a mass that does not match the stated peptide describes a very pure batch of something else. Endotoxin and sterility are separate tests again, and most certificates in circulation are purity-only, meaning they say nothing about pyrogen load. A missing batch code is the other common gap: without one, the report cannot be tied to the vial in your hand.

98% is the conventional threshold the major analytical labs treat as a clean result, and 95% is roughly where most suppliers stop making claims. These are conventions, not a safety standard set by any regulator. A high purity figure on an otherwise incomplete panel — no endotoxin, no mass spec, no batch — is weaker evidence than a slightly lower figure on a full panel.

It depends entirely on the compound, and for most of them nobody has actually measured it. Where a compound has an approved label there is a real figure — semaglutide's in-use stability is 56 days, for example. For the majority of research peptides there is no approved label and no published stability study, so any specific number you see quoted is someone's assumption. Of the 87 compounds indexed here, only 14 have compound-specific stability data from a label or peer-reviewed study; the rest say so on their profile rather than repeating a generic figure.

Because it would be making it up. Doses that appear in published literature or approved labelling are recorded on each compound's profile, attributed to the study or label they came from — that is a record of what was administered in research, not a recommendation for you. The studies those figures come from often bear no resemblance to any individual's situation, and most of these compounds have no human dosing data at all.

Yes, and it is the most consequential handling choice most people make without thinking. Bacteriostatic water contains 0.9% benzyl alcohol as a preservative, which is what makes entering the same vial repeatedly reasonable. Sterile water has no preservative — it is sterile when opened and not afterwards — so it suits a single draw only. Using sterile water for a multi-dose vial is the common mistake.

Not estimate it. A device only delivers what it can be set to, and splitting the difference by eye on a syringe without that mark is how dosing errors happen. The fix is to change the dilution so the number you need lands on a mark — the same dose at a different solvent volume might be a clean 15 or 20 units. The dial-fit tool works out which volumes make your dose land exactly.

Legal status varies by compound and by country, and 'research chemical' is not a legal category that permits human use. Some compounds indexed here are approved medicines in some jurisdictions, some were approved and later withdrawn, some are prohibited in sport, and most are approved nowhere. Each profile records the regulatory status we could verify from primary sources. None of that is legal advice.

No, and there is no affiliate arrangement, no sponsored placement and no advertising anywhere on the site. Nothing here is for sale and no supplier has paid for a mention. That is the point of it being non-commercial: a site that sells the thing it reviews has an obvious reason to be generous about it.

Every compound was checked against primary sources — PubChem, UniProt, PubMed, FDA and EMA labelling, and ClinicalTrials.gov. 259 citations survived that check, and each one was confirmed to resolve to a real paper. Around 30 fabricated or misattributed references were removed in the process. Values that could not be verified were left blank rather than filled with a plausible guess, and each profile lists what could not be confirmed.

Yes — submitting a certificate of analysis is the most useful thing you can add, and it can be entirely anonymous. Submissions go into a moderated queue before appearing in the library. Drop the PDF into the reader and it will fill most of the form out for you.