Plain-language glossary
The terms you will run into, without the jargon.
503A pharmacy
A state-licensed compounding pharmacy that makes a medicine for one specific patient with a prescription. It cannot legally make big batches to sit on a shelf.
503B outsourcing facility
An FDA-registered facility that can compound larger batches for office use (a clinic can stock it), held to stricter manufacturing (cGMP) standards than a 503A.
Category 1 (bulk substances)
Substances FDA allows to be compounded under section 503A while it finishes its review. Not the same as FDA-approved.
Category 2 (bulk substances)
The FDA 'do not compound' list, substances flagged for significant safety risk. Being removed from Category 2 does NOT by itself make something legal to compound.
PCAC
The FDA's Pharmacy Compounding Advisory Committee. It reviews whether a substance should be allowed for compounding and advises FDA. Its recommendation is not the final word.
COA (Certificate of Analysis)
A lab report on a specific batch. A real one names an independent lab, shows the batch/lot number, and reports purity (by HPLC) and sterility. A batch number on the vial should match the COA.
HPLC
High-performance liquid chromatography, the lab method used to measure a compound's purity. A trustworthy COA shows an HPLC purity result, not just a number with no method.
Research Use Only (RUO)
A label meaning 'for laboratory research, not for humans.' It is a liability shield for the seller, not a safety certification or a legal path to use something in your body. FDA has rejected RUO labels as a defense for products actually marketed for human use.
Compounding pharmacy
A pharmacy that custom-makes a medicine (for example, a specific dose or form) rather than dispensing a mass-manufactured product. Legitimate ones are state-licensed and dispense on a prescription.
NABP
The National Association of Boards of Pharmacy. It runs pharmacy accreditation and a public tool to check whether an online pharmacy is safe or 'Not Recommended.'
PCAB
Pharmacy Compounding Accreditation Board (part of ACHC). PCAB accreditation means a compounding pharmacy was audited against USP sterile/non-sterile compounding standards. It is held by a small minority of pharmacies.
LegitScript
A certification widely required by Google, Meta, Visa, and Mastercard before a pharmacy can advertise or take payments online. You can look up whether a specific website is LegitScript-certified.
.pharmacy domain
A web address ending in .pharmacy has been vetted by NABP and cannot be faked. It is a simple visual trust signal.
Prescriber of record
The licensed clinician who writes and stands behind your prescription. Legitimate peptide therapy runs through a prescriber who evaluates you first.
GLP-1 receptor agonist
A drug class that includes semaglutide (Ozempic, Wegovy) and, with GIP, tirzepatide (Mounjaro, Zepbound). Brand versions are FDA-approved; compounded copies are restricted and tied to shortage rules.