Frequently asked questions

Research Use Only (RUO) is a regulatory classification. It means the material is intended strictly for in-vitro laboratory or preclinical research. It is not approved by any regulator for human consumption, therapeutic use, or veterinary administration, and it is not manufactured or released to the standards required for any of those.

No. researchuseonlypeps is an independent reference and review publisher. There is no cart and no checkout on this site, and we never take payment, hold stock, or ship anything. When you follow a link to a vendor you leave this site entirely, and everything after that point is between you and that vendor.

By reverse-phase HPLC, usually on a C18 column read at 220 nm, reported as a percentage of total peak area. The percentage on its own is not the evidence. The chromatogram is, because that is where a wide peak with impurities under its shoulder becomes visible. We expect a vendor to publish the trace, not just the figure.

No, and this is the single most common misreading of a certificate. HPLC purity tells you how much of one substance is present. It says nothing about which substance. Identity is established by mass spectrometry, comparing observed molecular weight against the theoretical weight for the stated sequence. Purity without mass spec is a pure sample of something unconfirmed.

A batch or lot identifier that matches the vial, a named independent laboratory, a report date, the HPLC chromatogram, a mass spectrometry result with observed against theoretical mass, and ideally an endotoxin figure in EU/mg and a residual solvent screen. We publish a free twelve-point checklist that walks each of these in the order they appear on a real document.

Bacterial endotoxin is heat-stable and survives both autoclaving and sterile filtration, so a material can be chemically pure and still carry it. It is reported in endotoxin units per milligram. It is also the most frequently omitted panel in this market, because it is the one most likely to fail. Absence of the panel is itself a result.

The label weight is the mass of the lyophilised powder, which includes residual water, counter-ion salt (usually TFA from purification), and residual solvent. Net peptide content states how much of that powder is actually peptide. Two vials with identical HPLC purity can differ meaningfully once net content is accounted for.

Lyophilised powder is generally stored at -20°C, sealed and protected from light. Under those conditions most sequences hold their stated purity for extended periods. Reconstituted solution is far less stable than dry powder, which is why material ships lyophilised.

Against a published rubric built from documents: whether a certificate exists per batch, whether the laboratory is named and independent, whether the analytical panel is complete, whether batch numbers are traceable, and how the vendor handles a correction when something is wrong. Scores are opinion formed from evidence, and they are not for sale.

It does not. No link on this site earns a commission or a referral fee, no vendor pays to be listed, and the site carries no advertising. The people who publish it are paid by one vendor in the directory for marketing work. That connection does not buy a score, advance sight of a review, removal of a safety alert, or suppression of a competitor. What it is, and what it cannot change, is set out on our disclosure page.

No. We do not publish dosing schedules, administration routes, cycles, or protocols, and we do not describe any peptide as a treatment for anything in any species. Reference profiles summarise published preclinical literature and grade how strong the evidence behind it is. Nothing on this site is medical advice.

Use the contact form at https://researchuseonlypeps.com/contact and tell us the page and what is wrong. If we got it wrong we correct it on the page and say what changed. Corrections stay visible rather than being quietly edited out.