Buying and checking quality

Research peptides aren't regulated like medicines, so purity and the real amount in a vial vary between sellers and even batches. A prescription from a licensed pharmacy is the regulated option.

Certificate of analysis (COA)

• Matches your vial: the lot or batch number on the COA is the one printed on your vial.
• From an independent lab, named and dated, not only the seller's own.
• Identity: mass spectrometry (MS) confirming it's the right molecule.
• Purity: HPLC, usually 98% or higher.
• Amount: the measured mg per vial, close to the label.
• For injectables, ideally: endotoxin and sterility results too.

Independent labs will test a vial you send them, a good check on a new seller.

Red flags

• No lot number on the vial, or the same COA for every batch.
• A COA with no lab name, no date, or that looks edited.
• Prices far below everyone else's.
• Powder that looks wet or melted, or a vial with no vacuum on a brand that normally has one.

BAC water

• Buy sealed vials from a pharmacy or medical supplier and check the expiry date.
• Optional check with a pH strip: bacteriostatic water should read 4.5–7.0. Put a drop on the strip from a syringe; never dip a strip into the vial. A pass doesn't prove it's sterile, but a fail means don't use it.
• It should be perfectly clear.