§ Regulatory & Safety
503A vs. 503B Pharmacy
Two regulatory categories of compounding pharmacies with materially different oversight.
Fact-checked 12 May 2026Plain-English Reference
503A pharmacies compound for individual patients with patient-specific prescriptions and are state-regulated. 503B pharmacies ("outsourcing facilities") compound in larger volumes for healthcare providers and are FDA-registered, with more stringent quality requirements. Many telehealth GLP-1 compounders use 503B partners; some still rely on 503A.