503B bulk drug substances list
Where a compounded drug parts company with an FDA-approved one, where 503A parts company with 503B, and which accreditation programs tell them apart.
What is 503B bulk drug substances list?
FDA's roster of active ingredients a 503B outsourcing facility is permitted to compound from once no shortage is on the books.
A proposal dated 30 April 2026 would strike semaglutide, tirzepatide and liraglutide off it. Finalized, that shuts the last route by which these drugs could be compounded at scale.
Which GLP-1s can be compounded →
GLP Watchdog writes these definitions from FDA labels and peer-reviewed PubMed literature.
Where 503B bulk drug substances list comes up on this site
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