7 Questions to Ask Before You Buy Peptides From Anyone

Anonymous operations and PO boxes are the first red flag. Legitimate suppliers operate under a registered LLC or corporation with a traceable address and business registration you can look up.

A supplier should name the facility that manufactures their product — not just claim "US quality" or cite compliance language that doesn't actually apply to research-use compounds. That facility, and any cGMP-compliance or manufacturing registration it claims, should be something you can independently verify — not something you have to take on faith.

A COA from the supplier's own lab is not independent verification. The COA must come from an accredited third-party laboratory, reference the specific batch number, and be dated within a reasonable window of your purchase.

Purity alone doesn't tell the whole story. Identity testing helps confirm the compound is what it claims to be. Quantity testing checks whether the stated amount is actually present. Heavy metals testing helps identify potential elemental contamination from manufacturing or handling.

Peptides can differ in stability, formulation and storage requirements. A serious supplier should provide clear information about the product format, appropriate storage conditions and any temperature-sensitive shipping requirements rather than relying on one-size-fits-all instructions.

Suppliers confident in their testing publish COAs openly. Having to specifically request documentation — especially if there's delay or pushback — is a signal that the documentation may not exist or may not hold up to scrutiny.

The language a supplier uses tells you how they operate. Legitimate research suppliers use "research use only" framing, link to published literature, and avoid unsubstantiated therapeutic claims. Hype, before/after photos, and disease cure language are the kind of claims that can draw FDA and FTC scrutiny — and a trust signal of the wrong kind.