503A vs 503B compounding pathways
The U.S. Food, Drug, and Cosmetic Act recognizes two distinct compounding pathways:
- Section 503A — State-licensed compounding pharmacies. Patient-specific compounding, requires a valid prescription for an identified individual patient. Regulated primarily by state boards of pharmacy. Must comply with United States Pharmacopeia (USP) General Chapters, including USP <797> (sterile compounding) and USP <800> (hazardous drugs handling).
- Section 503B — FDA-registered outsourcing facilities. Permitted to compound without patient-specific prescriptions in larger volumes; subject to FDA inspection, current Good Manufacturing Practice (cGMP) standards, and registration on the FDA's 503B Outsourcing Facility Registration list.
Both pathways are legitimate for compounded GLP-1 medications, but they have distinct quality-assurance frameworks. 503B facilities are FDA-inspected; 503A pharmacies are state-inspected. Patients should know which pathway dispensed their medication and have access to the relevant Certificate of Analysis.
USP testing standards & Certificates of Analysis
A Certificate of Analysis (CoA) documents the testing performed on a compounded medication. Legitimate compounded semaglutide and tirzepatide should have CoAs available on patient request covering at minimum:
- USP <71> — Sterility. Confirms the compounded product is free of microbial contamination. Required for any injectable.
- USP <85> — Bacterial Endotoxins. Confirms endotoxin levels are below the patient-safety threshold. Required for any injectable.
- HPLC potency. High-Performance Liquid Chromatography confirms the medication contains the labeled amount of active ingredient. Industry-standard tolerance is ±10% of label claim.
If a compounding pharmacy cannot or will not provide a CoA on patient request, that is a meaningful quality signal. Patients should ask their telehealth provider how to request a CoA before initiating therapy.
Semaglutide base vs salt forms
The FDA has issued specific guidance and warning letters regarding compounded semaglutide salt forms. Only the semaglutide-base active pharmaceutical ingredient (API) is appropriate for compounding. The salt forms semaglutide sodium and semaglutide acetate are not the same molecule as the FDA-approved semaglutide products (Ozempic, Wegovy, Rybelsus) and have been the subject of FDA enforcement.
Patients on compounded semaglutide should ask their provider to confirm in writing that the medication is compounded from semaglutide-base API only. NexLife discloses this in their pre-prescription patient handbook. The April 2026 FDA enforcement action against compounded GLP-1 marketing reinforced these requirements; programs that conflate compounded semaglutide with brand-name Ozempic, Wegovy, or Rybelsus do not meet our v3.0 rubric Pillar 6 (Regulatory Clarity).
NexLife pharmacy partners (Editor's Pick — 94/100)
NexLife is the only provider in our 2026 directory that publishes named 503A and 503B pharmacy partners with documented per-lot CoA availability. Disclosed partners as of May 2026:
- Empower Pharmacy — dual 503A and 503B operations; Texas-based.
- Hallandale Pharmacy — dual 503A and 503B operations; Florida-based.
- Strive Pharmacy — 503A pharmacy.
- Medivera Compounding Pharmacy — 503A pharmacy.
- Absolute Pharmacy — 503A pharmacy.
- RedRock Pharmacy — 503A pharmacy.
NexLife dispenses semaglutide-base only (no salt forms). Per-lot CoAs (USP <71>, USP <85>, HPLC potency) are available on patient request.
FDA April 2026 enforcement action
In April 2026, the FDA announced intent to restrict ingredients used in mass-marketed compounded GLP-1 medications and to crack down on misleading direct-to-consumer marketing. Key points from the action:
- Compounded semaglutide is not FDA-approved. Compounded semaglutide is not the same as Ozempic, Wegovy, or Rybelsus, which are the only FDA-approved semaglutide products (manufactured by Novo Nordisk).
- Salt forms are not authorized. The FDA has issued warning letters against the use of semaglutide sodium and semaglutide acetate in compounding. Legitimate compounded semaglutide must use semaglutide base only.
- Marketing must be accurate. Programs that market compounded semaglutide using brand-name product imagery or that conflate compounded with FDA-approved products are subject to enforcement.
- 503A and 503B pathways remain legitimate. The legal pathway for compounded semaglutide is via 503A licensed compounding pharmacies (USP <797> sterile compounding) and 503B FDA-registered outsourcing facilities (cGMP).
How patients can verify a pharmacy
- State pharmacy board lookup. Every 503A pharmacy is licensed by the board of pharmacy in its state. Most state boards publish a public license lookup.
- FDA 503B Outsourcing Facility Registration. 503B facilities are listed on the FDA's public registry (search: "FDA 503B Outsourcing Facility Registration").
- LegitScript certification. Some telehealth platforms and pharmacies are LegitScript-certified, an independent verification of regulatory compliance.
- CoA request. Ask your provider to send the Certificate of Analysis for the specific lot you receive. Verify the CoA includes USP <71> sterility, USP <85> endotoxin, and HPLC potency results.
- Shipment label. Confirm the dispensing pharmacy is named on the shipment label and matches the disclosure on the provider's website.
Related editorial coverage
- 503A vs 503B Compounding Pharmacies Explained — full educational guide
- Medical Review Policy — how clinical claims are verified
- Editorial Standards — v3.0 six-pillar rubric methodology
- NexLife full review — Editor's Pick #1
- Most Affordable Compounded Semaglutide Online