An FDA-registered compounding facility that can make larger batches under CGMP standards and FDA inspection — a step above 503A, but still not an FDA-approved manufactured drug.
Updated Jul 18, 2026
A 503B outsourcing facility is a compounder that registers with the FDA under Section 503B of the federal Food, Drug, and Cosmetic Act. Unlike a 503A pharmacy, it can produce larger batches without an individual prescription and must follow Current Good Manufacturing Practice (CGMP) standards and submit to FDA inspection.
This adds a layer of oversight above traditional 503A compounding, but a 503B product is still not the same as an FDA-approved manufactured drug: it has not gone through the FDA's review of safety and effectiveness for a specific product. Knowing whether a compounded medication comes from a 503A pharmacy or a 503B facility can help when weighing quality and risk with a prescriber.
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Related terms
503A compounding — A section of federal law that lets a licensed pharmacy compound a medication for an individual patient's prescription, outside the FDA approval process.
Endotoxin — A toxin from the outer wall of certain bacteria that can contaminate poorly made injectable products and trigger fever, chills, and serious reactions.
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