Purity is the only thing separating one white powder from another. Here is exactly what we do about it.
We do not run our own purity numbers and ask you to trust them. Each lot is sent to a third-party analytical lab and assayed by HPLC, with mass spectrometry confirming identity. We buy the test whether or not we like the answer, and lots that come back under specification do not get listed.
Plenty of sellers post one flattering certificate and leave it up for years. Every vial we ship is printed with the batch number of the lot it came from. Email us that number and we send the assay for that exact lot. If the number on your vial and the number on the certificate do not match, something has gone wrong and we want to hear about it.
Lyophilised material is stable, but heat in transit is still the fastest way to ruin a vial. Orders go out in insulated mailers with gel packs, dispatched the same business day when placed before 2pm ET, so material spends as little time as possible in a hot truck.
We will not give you a protocol, a dose, or a route. Not because we are being cagey, but because these are research materials and that guidance would be exactly the thing that turns a legal sale into an illegal one. We will happily talk about purity, reconstitution with bacteriostatic water, storage temperature, and shelf stability — the chemistry, not the application.