- Created by
- Drug Quality and Security Act, 2013
- Quality rules
- CGMP required
- Main overseer
- FDA
- FDA-approved products?
- No
Where the term comes from
Section 503B was added to the Federal Food, Drug, and Cosmetic Act in 2013 by the Drug Quality and Security Act.
Registration is voluntary. A compounder that wants to produce larger batches, including drugs for hospitals and clinics to keep on hand, can register as an outsourcing facility and accept the extra oversight that comes with it.
What sets 503B apart from 503A
The two categories differ mainly in scale and in who watches over them:
- Quality standard: 503B facilities must meet current good manufacturing practice (CGMP) requirements. 503A pharmacies do not.
- Oversight: the FDA is the primary regulator of 503B facilities and inspects them on a risk-based schedule. State boards of pharmacy lead oversight of 503A pharmacies.
- Prescriptions: a 503B facility may compound with or without a patient-specific prescription, for example to supply office stock. A 503A pharmacy compounds for named patients.
- Reporting: 503B facilities must report adverse events and send the FDA a list of the drugs they have compounded twice a year.
- Registration: 503B facilities re-register and pay a fee every year. The FDA publishes a list of registered facilities with their inspection history.
What 503B does not mean
A drug from an outsourcing facility is still a compounded drug. It has not been through the FDA's approval process, so its safety and effectiveness haven't been demonstrated the way an approved product's have. CGMP rules improve consistency and sterility, but they are a manufacturing standard, not proof that a treatment works.
An FDA inspection report (Form 483) also isn't a final verdict. It lists observations, and the agency may or may not take further action.
How to use this information
If you're prescribed a compounded medication, you can ask whether it comes from a 503A pharmacy or a 503B facility, and you can check the FDA's public list of registered outsourcing facilities yourself. Either way, your clinician should explain why a compounded product was chosen and what's known about it.
It also helps to remember that the 503A and 503B labels describe the compounder, not the medicine's track record. A peptide or hormone made in a CGMP facility still has only the evidence behind it that exists in published research, and for many compounded products that evidence is limited. Quality of manufacture and proof of benefit are separate questions.
503B outsourcing facility: common questions
Is a 503B facility a drug manufacturer?
Not exactly. It compounds rather than manufactures approved products, but it must meet manufacturing-level CGMP standards and is inspected by the FDA.
Are 503B drugs FDA-approved?
No. Outsourcing facility products are compounded drugs and haven't gone through FDA premarket review for safety and effectiveness.
Why do clinics buy from 503B facilities?
Because 503B facilities can supply drugs without a patient-specific prescription, clinics and hospitals use them for office stock such as ready-to-use injectables.
How can I check whether a facility is registered?
The FDA keeps a public list of registered outsourcing facilities, including locations, inspection dates and any related actions.
Is a 503B product always safer than a 503A product?
CGMP standards and FDA inspections add safeguards, but neither guarantees a product is right for you. Quality varies by facility within each category.
What happens if a facility doesn't renew its registration?
Outsourcing facilities must re-register each year between October and December. Those that don't are removed from the FDA's list on January 1.
Sources
We cite government agencies, professional societies and peer-reviewed research. See our editorial policy.
- Compounding Laws and PoliciesU.S. Food and Drug Administration
- Compounding and the FDA: Questions and AnswersU.S. Food and Drug Administration
- Information for Outsourcing FacilitiesU.S. Food and Drug Administration
- Registered Outsourcing FacilitiesU.S. Food and Drug Administration