Glossary
Compounded vs branded
Also called Compounded semaglutide, Compounded tirzepatide, Brand-name drug, Compounding pharmacy
A branded drug is the FDA-approved product from its maker. A compounded drug is mixed by a pharmacy or outsourcing facility and is not FDA approved.
In more detail
Compounding exists so pharmacies can make medicines for patients whose needs an approved product does not meet. Compounded drugs do not go through FDA approval for safety, effectiveness or quality. FDA explains that pharmacies compounding under section 503A are mainly overseen by state boards, while outsourcing facilities under 503B are inspected by FDA and held to manufacturing standards.
During GLP-1 shortages, compounded semaglutide and tirzepatide became common. FDA then documented overdoses linked to unit confusion with compounded vials.
Why it matters
A compounded vial can have a different concentration from one pharmacy to the next. Always dose from your vial's label, not from a chart made for a different product. See 503A vs 503B.
Related terms
- 503A vs 503BThe two federal paths for drug compounding in the US. 503A covers state-licensed pharmacies filling patient prescriptions; 503B covers FDA-registered outsourcing facilities that follow manufacturing standards.
- Insulin pen vs vialA pen is a prefilled cartridge with a dial that sets each dose. A vial holds liquid (or powder to mix) that you draw with a separate syringe.
- Research use only (RUO)A label sellers put on compounds that are not approved drugs, stating they are sold for laboratory research and not for human use.
- Units vs mg vs mcgMilligrams (mg) and micrograms (mcg) measure how much peptide you take. Syringe units measure how much liquid you draw. You need the vial's concentration to convert one into the other.
Peptides where this comes up
Sources
Each source is labeled by where the information comes from. How we label sources
- RegulatoryCompounding and the FDA: Questions and Answers(opens in a new tab)
FDA · checked
- RegulatoryFDA alerts health care providers, compounders and patients of dosing errors associated with compounded injectable semaglutide products(opens in a new tab)
FDA · checked
Updated