503A or 503B? Ordering compounded medications the compliant way

Compounded medications reach your clinic through one of two federal pathways. Section 503A of the Federal Food, Drug, and Cosmetic Act covers compounding by state-licensed pharmacies (and physicians) for identified patients. Section 503B, added by the Drug Quality and Security Act in 2013, covers FDA-registered outsourcing facilities. Knowing which pathway fits each order is the core of ordering compounded drugs compliantly.

Under either pathway, compounded drugs are not FDA-approved: FDA doesn't review them for safety, effectiveness or quality before they are marketed.

503A: patient-specific compounding by state-licensed pharmacies

A drug compounded under section 503A is exempt from FDA's approval, "adequate directions for use" labeling and cGMP requirements only if it is compounded for an identified individual patient, based on a valid prescription order or a prescriber-approved notation that a compounded product is necessary for that patient.

A named patient. FDA's guidance says the prescription must identify the patient. A prescription written for the prescriber, when the prescriber isn't the patient, doesn't qualify.
State oversight. State boards of pharmacy have primary responsibility for day-to-day oversight of these pharmacies. They are not subject to federal cGMP requirements.
Limited anticipatory compounding. A pharmacy may compound limited quantities ahead of time based on its history of receiving prescriptions, but FDA's position is that it can release a 503A drug only after it receives a valid patient-specific prescription.
Ingredient rules. Bulk drug substances must meet a USP or NF monograph, be a component of an FDA-approved drug, or appear on FDA's 503A bulks list. They must come from an FDA-registered establishment with a valid certificate of analysis.
No regular copies. A 503A pharmacy may not compound, regularly or in inordinate amounts, drugs that are essentially copies of a commercially available product.

503B: FDA-registered outsourcing facilities

An outsourcing facility compounds sterile drugs at one location and has registered with FDA under section 503B. It doesn't have to be a licensed pharmacy, and under the statute it may or may not obtain prescriptions for identified patients.

cGMP and inspection. Outsourcing facilities must meet current good manufacturing practice requirements and are inspected by FDA on a risk-based schedule.
Registration and reporting. They register with FDA every year, report what they compounded every six months (June and December), and must submit adverse event reports to FDA.
Bulk ingredients. They generally can't compound from a bulk drug substance unless it is on FDA's 503B bulks list or the drug is on FDA's drug shortage list at the time of compounding, distribution and dispensing.
No resale. A 503B drug may not be sold or transferred by anyone other than the facility that made it. Administering it in a health care setting, or dispensing it on a valid prescription, is allowed.
Labeling. Labels must identify the product as compounded and say "Not for resale." Product distributed without a patient-specific prescription must also say "Office Use Only."

What "office use" means, and where states differ

Office stock, or office use, means compounded drugs a clinic keeps on hand to administer to patients as they present, rather than drugs ordered for one named patient. FDA's 2016 guidance on the 503A prescription requirement is direct: hospitals, clinics and practitioners can obtain non-patient-specific compounded drugs from 503B outsourcing facilities.

State law is less uniform. Some states expressly allow pharmacies to supply compounded drugs for office use. Texas lets a pharmacy dispense and deliver "a reasonable quantity" of a compounded drug to a practitioner for office use, subject to conditions such as verifying raw-material sources and following USP guidelines. California's pharmacy law similarly lets a pharmacist furnish a reasonable quantity of compounded drug product to a prescriber for office use.

State permission doesn't change the federal analysis. FDA's guidance acknowledges that some state boards may authorize prescriptions that don't name individual patients, and says those prescriptions don't meet the patient-specific requirement in section 503A. If you need stock on the shelf, the federal pathway FDA points to is 503B.

Office-stock orders can carry their own documentation step. When an outsourcing facility relies on your clinical-difference determination (because the product would otherwise be essentially a copy of an approved drug), FDA's guidance says the order should state the change and the clinical difference it produces, and that the drug will go only to patients with that need. FDA's example: "1 mg, pediatric patients need lower dose."

What to verify before you order

From a 503A pharmacy

A license in the patient's state. States can require out-of-state pharmacies to be licensed or registered before shipping in. Delaware requires a nonresident pharmacy permit to ship, mail or deliver prescription drugs to a patient in Delaware; New York requires registration of out-of-state pharmacies that ship into New York. Check that state's board, plus the home-state license and any discipline.
Ingredient sourcing. Ask how each active ingredient qualifies under 503A and whether the pharmacy keeps supplier certificates of analysis on file.
Your own authority. Confirm you're licensed to prescribe for a patient located in that state.

From a 503B outsourcing facility

Current FDA registration. FDA's registered outsourcing facility list (most recently updated September 8, 2026, when we checked) shows each facility's last inspection date, whether a Form 483 was issued, recalls, and actions such as warning letters. A 483 isn't a final agency determination, but read it.
Licensure in your state. Some states license outsourcing facilities separately. California bars a nonresident outsourcing facility from compounding drugs for distribution or use in California without a California outsourcing license.
Quality evidence. Ask for lot-level release testing results.
Ingredient eligibility. Ask whether each bulk substance is on the 503B bulks list, or the drug is on FDA's shortage list.

How patient-specific prescribing works in practice

Evaluate the patient and document the need. FDA describes compounding as serving patients whose clinical needs can't be met by an FDA-approved drug. Your chart should show why this patient is one of them.
Write a prescription that names the patient. Clinic-name or "office use" prescriptions don't satisfy 503A.
Document any significant difference. If the formulation resembles a commercially available drug, state the change and why it matters for this patient. FDA's examples include "No Dye X, patient allergy" and "Liquid form, patient can't swallow tablet." A patient name plus formulation isn't enough, and a lower price doesn't count. FDA has said it doesn't intend to act against a 503A compounder that fills four or fewer prescriptions for an essential copy in a calendar month; prescriptions documenting a significant difference don't count toward the four.
Send it to an appropriately licensed pharmacy. Confirm the pharmacy can lawfully ship to the patient's state.
Receive, then administer or dispense. The pharmacy provides the drug to the patient or prescriber, as the prescription directs. It's that patient's medication; shelf stock belongs on a 503B order.

On MedGrid, patient-specific 503A prescriptions route to a partner pharmacy licensed in the patient's state, and the catalog you see is gated by your credentials and state. The clinical documentation is still yours.

Current examples: GLP-1s and peptides

FDA declared the tirzepatide injection shortage resolved (October 2, 2024, reaffirmed December 19, 2024) and the semaglutide injection shortage resolved on February 21, 2025; the transition periods for compounders ended between February and May 2025.

In an April 1, 2026 update, FDA noted that neither drug is on the 503B bulks list or the shortage list, and said it may consider a compounded semaglutide and vitamin B12 injection, with strengths within 10% of commercially available products, to be essentially a copy. On April 30, 2026, FDA proposed not to include semaglutide, tirzepatide or liraglutide on the 503B bulks list; the extended comment period closed July 30, 2026. Check FDA's compounding pages for the final decision before ordering.

Peptides are another moving target. FDA's Pharmacy Compounding Advisory Committee met July 23-24, 2026 to discuss seven peptide-related substances, including BPC-157, for the 503A bulks list. A committee discussion doesn't change the list; the list is set through FDA notice-and-comment rulemaking (21 CFR 216.23). Confirm a substance's status before prescribing it.

This article is general information, not legal advice. Rules vary by state; confirm specifics with your counsel and your state boards.

503A or 503B? Ordering compounded medications the compliant way

503A: patient-specific compounding by state-licensed pharmacies

503B: FDA-registered outsourcing facilities

What "office use" means, and where states differ

What to verify before you order

From a 503A pharmacy

From a 503B outsourcing facility

How patient-specific prescribing works in practice

Current examples: GLP-1s and peptides

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