Frequently asked questions
What does 'research use only' mean?
It means these compounds are supplied strictly for laboratory research. They are not approved drugs, supplements, or cosmetics, and they are not intended for human or veterinary use, nor for any diagnostic or therapeutic purpose. We do not provide dosing guidance for human use and cannot answer questions framed around personal use.
How is purity verified?
Every batch is tested by HPLC and mass spectrometry at an independent third-party laboratory. HPLC establishes chromatographic purity; mass spectrometry confirms molecular identity. We publish results at a floor of ≥99%.
Do you provide certificates of analysis?
Yes, and we publish them rather than holding them pending request. Every batch has a COA available on the site showing identity, purity, and the testing laboratory. If a supplier will not show you a COA before purchase, that is meaningful information.
How should lyophilized peptides be stored?
Store lyophilized powder at -20°C protected from light, where stability extends for extended periods. Once reconstituted, hold at 2-8°C and use within approximately 30 days. Avoid repeated freeze-thaw cycles, which degrade peptide integrity — aliquot into single-use volumes if your protocol spans multiple sessions.
What is the correct reconstitution procedure?
Direct bacteriostatic water slowly down the interior wall of the vial rather than onto the powder directly, then swirl gently until fully dissolved. Never shake or vortex — mechanical agitation at the air-liquid interface denatures peptides and is a frequent cause of unexplained potency loss between aliquots.
Why do molecular weights differ between suppliers for the same compound?
Usually because the compounds are not actually the same molecule. TB-500 is the clearest example: some suppliers ship full-length thymosin beta-4 (approximately 4963 g/mol) and others ship a short fragment based on the LKKTETQ actin-binding motif (approximately 889 g/mol). Always reconcile the stated molecular weight on the COA against the published literature you intend to compare against.
How is the product shipped?
Same-day dispatch on orders before 2pm ET. Lyophilized peptides are shipped with cold chain packaging within the United States. Lyophilized material tolerates brief ambient exposure in transit without meaningful degradation.
Can you advise on dosing?
No. These are research chemicals and we do not provide dosing guidance for human use under any circumstances. Questions about experimental concentrations for in vitro or animal model work should be resolved against the published literature for your specific model and endpoint.