Compounding pharmacies create custom medications to meet patient needs. These pharmacies must follow strict U.S. Food and Drug Administration (FDA) regulations to ensure safety and quality. When deciding between a 503A or 503B compounding pharmacy, understanding the key differences helps healthcare providers make informed choices.
If you’re looking up terms like “compounding pharmacies 503B” or “compounding pharmacies 503A,” you’re on the right page. Here, we’ll show you the differences between the two and provide updates on the latest regulations.
Types of Compounding Pharmacies: 503A vs 503B
There are two main types of compounding pharmacies: 503A and 503B. The Drug Quality and Security Act of 2013 established the 503B category to improve oversight and ensure higher quality standards. Pharmacies that do not apply for 503B designation remain classified as 503A.
Here’s a quick table to help you distinguish the two more easily:
|
503A Compounding Pharmacies |
503B Compounding Pharmacies |
|
Prepare medications only for specific patients based on prescriptions. |
Also known as 503B outsourcing facilities. |
|
Use FDA-approved ingredients. |
Manufacture medications in bulk for office use. |
|
Cannot mass-produce medications or ship them interstate. |
Follow FDA 503B guidelines, including Current Good Manufacturing Practices (CGMP). [1] |
|
Follow the guidelines set by state pharmacy boards. |
Register compounded drugs with the FDA. |
|
Allowed to ship products across state lines. |
Both types of compounding pharmacies play an important role in providing patients with custom-made medications, but 503B Pharmacies have many advantages, such as the ability to compound IM and IV nutrient therapy products for in-office use without the need for an individual prescription.
However, healthcare providers needing office-use products often prefer 503B facilities due to their ability to produce bulk supplies under strict manufacturing standards.
What can 503B compounding pharmacies make?
503B outsourcing facilities can only manufacture drugs under specific conditions:
-
The FDA includes the drug on the 503B bulk list due to clinical necessity
or
-
The medication appears on the FDA’s drug shortage list.
The FDA continues to review and update the 503B bulks list, which was last changed on August 21, 2023, and lists “Bulk Drug Substances Included on the 503B Bulks List” and “Bulk Drug Substances Not Included on the 503B Bulks List.” [2] However, as of 2025, ingredients fall into three categories: [3]
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Category 1: These substances may qualify for inclusion on the 503B bulks list and be nominated with sufficient supporting information. Until the FDA makes a final ruling, outsourcing facilities can compound drugs using these substances as long as they meet specific guidelines.
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Category 2: These substances were nominated with enough information for evaluation but have significant safety concerns. The FDA does not permit their use in 503B compounding. If a substance is placed in this category, the FDA provides safety risk details and may take action against facilities that compound it.
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Category 3: These substances were nominated but lack adequate supporting information for FDA evaluation. They are not eligible for the policies that apply to Category 1 substances. Facilities cannot compound drugs with these substances unless they are re-nominated with sufficient supporting data.
Recent FDA updates have reclassified several substances, making them unavailable for 503B production. Some of these may still be compounded under 503A patient-specific compounding rules.
503B Compounding Pharmacies and FDA Restrictions on Tirzepatide and Semaglutide
503B outsourcing facilities have been able to produce compounded tirzepatide and compounded semaglutide while they were on the FDA’s shortage list. However, FDA has no determined these items are no longer in shortage and have given 503B pharmacies the following deadlines: [4]
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Semaglutide: 503B pharmacies can compound it until May 22, 2025, or until the court issues a decision on the preliminary injunction motion in Outsourcing Facilities Association v. FDA (whichever happens later).
-
Tirzepatide: 503B pharmacies can compound it until March 19, 2025.
These changes mean healthcare providers must prepare for new sourcing options once these deadlines pass.
Wrapping Up
Both 503A and 503B pharmacies play vital roles in medication compounding. Selecting between them depends on specific needs, production capabilities, and compliance with FDA regulations. Compounding pharmacies under 503A and 503B offer diverse solutions for healthcare providers and patients alike.
At Legere Pharmaceuticals, we understand the importance of providing high-quality, compliant medications to your patients. As regulations evolve, having a trusted pharmaceutical partner is more crucial than ever.
Contact us today to explore our physician-exclusive products and discover how we can support your practice with top-tier solutions.
FAQs
What is a 503B compounding pharmacy?
A 503B pharmacy produces medications for individual prescriptions and manufactures bulk supplies for healthcare providers. These facilities follow FDA 503B guidelines, ensuring compliance with CGMP requirements similar to pharmaceutical manufacturers.
What is a 503A compounding pharmacy?
A 503A pharmacy prepares medications based on patient-specific prescriptions. These pharmacies must meet 503A patient-specific compounding standards but cannot produce large batches or supply medications for office use.
What is the difference between 503A and 503B pharmacies?
The primary difference lies in production capabilities and oversight. 503B facilities meet 503B quality standards, allowing bulk manufacturing and interstate distribution. 503A pharmacies focus on individual prescriptions and must comply with 503B compliance requirements when applicable.
Sources:
1 – U.S. Food and Drug Administration. (2021, January 7). Current good manufacturing practice—Guidance for human drug compounding outsourcing facilities under section 503B of the FD&C Act: Guidance for industry. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/current-good-manufacturing-practice-guidance-human-drug-compounding-outsourcing-facilities-under
2 – U.S. Food and Drug Administration. (2024, May 16). 503B bulk drug substances list. https://www.fda.gov/drugs/human-drug-compounding/503b-bulk-drug-substances-list
3 – U.S. Food and Drug Administration. (2025, January 7). Bulk drug substances used in compounding under section 503B of the FD&C Act. https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503b-fdc-act
4 – U.S. Food and Drug Administration. (2025, March 10). FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize. https://www.fda.gov/drugs/drug-safety-and-availability/fda-clarifies-policies-compounders-national-glp-1-supply-begins-stabilize
Jon Legere
Jon Legere is the Director of Marketing at Legere Pharmaceuticals, where he oversees all strategic marketing initiatives, brand development, and customer engagement efforts. With an MBA and 11 years of specialized experience in the dietary supplement industry, Jon brings a wealth of knowledge in consumer behavior, product positioning, and digital marketing strategies. His expertise has been pivotal in driving growth, innovation, and market share for Legere Pharmaceuticals, as he remains committed to promoting health and wellness through cutting-edge supplements.
