Before you buy

The vendor landscape

Who actually makes this stuff, who resells it, and why the same vial costs $30 from one site and $90 from another.

Reading a certificate of analysis

Purity, identity, endotoxin, sterility. What each test means, what a real one looks like, and what the numbers do and do not tell you.

Lot numbers, third-party testing, and checking for yourself

How to tie a certificate to a vial, why independent testing changed the market, and how to send a sample yourself.

Red flags, scams, and how people lose money

The patterns that repeat: fake certificates, the payment-processor shuffle, the vanishing vendor, and the underdosed bargain.

When it arrives

The first ten minutes with a package: what to check, what to photograph, and what to put in the fridge.