Research brief · 2026-09-09
What Is a Compounded Drug?
Compounding is one of the oldest jobs in pharmacy, and one of the least understood. The FDA defines it as combining, mixing or altering ingredients to create a medication tailored to the needs of an individual patient. The classic examples are a patient allergic to a dye in the commercial tablet, a child who needs a liquid version that no manufacturer makes, or a dose strength that is not sold.
The defining feature is regulatory. Compounded drugs are not FDA-approved. The FDA's own compounding pages state plainly that the agency does not verify the safety, effectiveness or quality of compounded drugs before they are marketed. The approval process, with its clinical trials and label review, applies to the manufactured product, not to a pharmacy's version of it.
The 2013 Drug Quality and Security Act, passed after a 2012 outbreak of fungal meningitis traced to a compounding pharmacy, created two lanes. Section 503A covers traditional pharmacies compounding for an individual patient's prescription, overseen primarily by state boards of pharmacy. Section 503B covers outsourcing facilities that can produce larger batches without patient-specific prescriptions, but must register with the FDA and follow federal current good manufacturing practice.
Compounders are generally barred from making what the law calls essentially a copy of an approved drug. The main exception is when the FDA lists the approved drug as in shortage. That is how compounded semaglutide and tirzepatide became common: both were on the shortage list, and the FDA declared the tirzepatide shortage resolved in December 2024 and semaglutide's in February 2025, which narrowed the legal basis for copies.
The limit is that 'compounded' means individualized, not reviewed. Quality depends on the specific pharmacy and its oversight, and no trial data describes any particular compounded preparation. Whether a compounded medication is appropriate is a decision for a physician and pharmacist together.
Sources
- U.S. Food and Drug Administration, Human Drug Compounding: Compounding and the FDA, Questions and Answers
- FDA.gov 2022
- Drug Quality and Security Act, Public Law 113-54, sections 503A and 503B of the FD&C Act
- U.S. Congress 2013
- U.S. Food and Drug Administration, FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize
- FDA.gov 2024, updated 2025
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