Independent guide
503A vs 503B Compounding Pharmacies
503A pharmacies and 503B outsourcing facilities operate under different federal frameworks; neither label means the compounded drug itself is FDA-approved.
Health information: This article is educational, not medical advice. FDA-approved branded medicines and compounded preparations are different regulatory categories. Treatment choice and prescribing require an appropriate clinician.
What matters
503A generally centers on patient-specific prescription compounding and state pharmacy oversight.
503B outsourcing facilities register with FDA and are subject to additional federal requirements.
Practical checks
FDA does not 'approve' pharmacies as if they were approved drug products.
The distinction matters when evaluating how and where a compounded medicine is prepared.
Sources
- HealthRX pricing
- HealthRX FAQ
- FDA: concerns with unapproved GLP-1 drugs
- FDA: 2026 compounding policy clarification
- FDA Wegovy prescribing information
- FDA Zepbound prescribing information
Provider prices and policies can change. We date-check unstable facts and distinguish provider claims from FDA or prescribing-information sources.