Compounded medication

A compounded medication is a drug preparation made by a pharmacist or outsourcing facility — combining, mixing, or altering ingredients to create a specific formulation — rather than a product manufactured in bulk by a pharmaceutical company and approved by the FDA under its own application. Compounding exists as its own regulatory category precisely because it is not the same review pathway as a mass-manufactured, FDA-approved drug.

503A and 503B: the two compounding categories

FDA regulation splits compounding into two types. A 503A pharmacy compounds against a prescription written for a specific, named patient, and is not required to follow the same manufacturing controls as a drug manufacturer. A 503B outsourcing facility can produce larger batches, including without a patient-specific prescription, but must operate under current good manufacturing practice (cGMP) requirements similar to a manufacturer’s. The two categories carry different oversight, recordkeeping, and quality-control obligations under federal law.

Compounded vs. manufactured

The distinction that matters for this term is regulatory pathway, not brand: a manufactured product goes through FDA approval as a single, fixed formulation; a compounded product is prepared individually by a pharmacy or outsourcing facility, and the conditions under which a given active ingredient can legally be compounded can change — for example, based on whether that ingredient is listed on an FDA drug-shortage list.

This page defines the category only. It does not address where any specific compounded product can be obtained or whether a given compounded preparation is appropriate for any individual — those questions sit with a licensed prescriber and pharmacy, not with this definition.