503A vs 503B pharmacies
Two different licences, two different rulebooks, two very different answers to "who checked this?"
Updated 2026-09-18
Disclosure: one company on this page — Coreage Rx — pays us a commission when a reader signs up through our link. It does not buy a better score, a higher ranking, or the removal of any criticism. The scoring rubric and the full disclosure are both published.
Ask a GLP-1 provider which pharmacy fills your prescription and you will get one of two answers. The difference between them is worth understanding, because it determines what oversight your medication has had.
Both are legal. Both are regulated. They are regulated differently, by different bodies, against different standards.
503A — the traditional compounding pharmacy
- Prepares medication for an individual patient against a specific prescription.
- Regulated primarily by state boards of pharmacy.
- Not required to follow the full federal manufacturing standards (cGMP) that apply to drug manufacturers.
- Cannot legally prepare medication in bulk for general sale — each preparation should answer a documented clinical need for a named patient.
503B — the outsourcing facility
- Can prepare larger batches, including without patient-specific prescriptions.
- Registers with the FDA and is subject to FDA inspection.
- Must follow cGMP manufacturing standards.
- Can only compound from bulk substances that appear on the FDA’s 503B Bulks List.
Why this is the live issue in 2026
On 30 April 2026 the FDA proposed excluding semaglutide, tirzepatide and liraglutide from the 503B Bulks List, on the basis that there is no clinical need for compounded versions now the shortages have resolved. The comment period closed on 30 July 2026.
If finalised, that would remove the pathway 503B facilities have been using to produce these drugs at volume. 503A pharmacies would still be able to compound for individual patients where there is a documented, patient-specific clinical reason — but routine, marketed compounded GLP-1 would not survive that change.
Important. This matters directly if you are considering prepaying for a year. Ask what happens to your remaining months if the supply route closes, and get the answer before you pay rather than after.
What to ask your provider
- Which named pharmacy fills my prescription?
- Is it a 503A pharmacy or a registered 503B outsourcing facility?
- What is the patient-specific clinical justification in my case?
- What is your contingency if the 503B Bulks List proposal is finalised?
Providers that answer those plainly are the ones worth your money. Most of the programmes we review do not publish the answers, which is itself informative — our programme reviews note who says what.
Programmes that avoid the question entirely
| Dispensed by | Product | Per month | Score |
|---|---|---|---|
| Coreage Rx Best overall on true monthly cost | Compounded | $149 | 4.5 |
| Trimi Lowest flat price with named pharmacies | Compounded | $99 | 4.6 |
| PlexusDx Pharmacy transparency and genetic testing | Compounded | $189 | 4.4 |
| Ozari Health Lowest advertised semaglutide price | Compounded | $86 | 4.4 |
| Ivím Health Unlimited clinician access | Compounded | $199 | 4 |
| Mochi Health Insurance concierge support | Compounded | $178 +$79 fee | 3.6 |
Ro dispenses only FDA-approved products, so neither category applies. Full comparison in brand-name vs compounded.
Read next
- What "compounded" actually means
Not a knock-off, not an approved drug. A specific legal category with specific consequences — explained without the scare tactics or the sales pitch.
- Brand-name or compounded?
The difference is not quality claims either way — it is what has been reviewed, by whom, and what recourse you have.
- Reading your label
What each line on the vial and the paperwork means, and the four things to check the moment the box arrives.
- Semaglutide programmes compared
17 programmes side by side — what each dispenses, under what authority, and what it really costs.
- Who should not take these
The contraindications and interactions an online questionnaire may not catch. Worth reading before you fill one in.