By SiriusRx|Education for practices

Clinical review pending. This article has not yet been reviewed by a licensed clinician, and we would rather say so than print a name that does not exist.

Most practices that add a cash-pay service line will work with a pharmacy that compounds. The rules depend on which federal pathway you use, and the difference shows up in daily operations: how you order, whether you can keep anything on the shelf, what labels you will see, and what you need to document. This guide explains the two pathways. It is general education, not legal advice, and it names no products.

First principle

Whichever pathway applies, drugs a pharmacy compounds are not FDA-approved. As FDA puts it, FDA does not verify their safety, effectiveness, or quality before they are marketed. That fact shapes consent, documentation, and advertising.

503A: a named patient

Section 503A of the Federal Food, Drug, and Cosmetic Act covers a licensed pharmacist in a state-licensed pharmacy or federal facility, or a licensed physician, who compounds for a patient.

  • For an identified patient. A 503A pharmacy compounds from a valid prescription for one patient.
  • Limited preparation ahead of a prescription. A 503A pharmacy may prepare a limited amount before it receives a prescription only from a history of valid prescriptions in an established relationship with the prescriber or the patient. Be cautious of any 503A pharmacy that promises stock or asks for volume forecasts in place of prescriptions.
  • Eligible ingredients only. A bulk substance has to meet a statutory criterion, such as a USP monograph, a component of an approved drug, or FDA's 503A bulks list. FDA's interim categories for nominated substances are enforcement policy set by guidance, and they can change.
  • No essentially copies of commercially available drugs, regularly or in inordinate amounts. The exception is a change that the prescriber determines makes a significant difference for the patient. FDA's guidance asks that this be noted on the prescription.
  • Oversight. State boards of pharmacy are the main oversight. Section 503A ties this work to the applicable USP chapters: USP General Chapter 795 for nonsterile preparations and 797 for sterile preparations.

What it means for your practice: the 503A pathway is the ordinary path for a patient's own prescription. In Virginia it is not a path for routine office stock. Virginia allows that office supply only for an emergency or as federal law allows. If a patient's prescription will be delivered to your office, Virginia generally requires the office to hold the right Board of Pharmacy permit, license, or registration, and requires a written contract between the pharmacy and the practitioner (Va. Code 54.1-3420.2 and 18VAC110-20-275). See in-office administration in Virginia.

503B: outsourcing facilities

Section 503B created a second category: outsourcing facilities.

  • Registered with FDA and inspected by FDA on a risk-based schedule.
  • Current good manufacturing practice applies. That is a manufacturing standard, separate from ordinary pharmacy practice.
  • Office stock is possible. A 503B facility may supply a practice for office use without a patient-specific prescription.
  • Narrower ingredient rules. A bulk substance has to be on FDA's 503B bulks list or used for a drug on FDA's shortage list. While FDA builds the 503B list, its interim policy allows certain nominated substances in Category 1. Essentially copies of approved drugs are prohibited.
  • Reporting. Each June and December, a 503B facility reports to FDA the drugs it prepared. It also submits adverse event reports under 21 CFR 310.305. Labels must include a statement that the drug was compounded. Office-stock labels must say "Office Use Only."

What it means for your practice: the 503B pathway is the one that can support lawful office stock, and only for eligible substances. Many substances a 503A pharmacy can prepare for a named patient are not eligible for 503B office stock at all.

Side by side

  • Who is it for? A 503A pharmacy serves an identified patient with a valid prescription. A 503B facility may serve patients or practices, and office stock is allowed.
  • Main regulator. A 503A pharmacy is overseen mainly by the state board of pharmacy. A 503B facility is overseen by FDA, plus state permits.
  • Quality standard. A 503A pharmacy follows USP chapters for preparations. A 503B facility follows current good manufacturing practice.
  • Ingredient rules. A 503A pharmacy uses the 503A criteria and FDA interim policy. A 503B facility uses the 503B bulks list, interim policy, or the shortage list.
  • Routine office stock in Virginia? Not from a 503A pharmacy. A 503B facility may supply it for eligible substances only.

Questions to ask

  • Is it permitted in Virginia, or registered as a Virginia nonresident pharmacy? For a 503B facility, confirm it is listed on FDA's registered outsourcing facilities page and permitted or registered in Virginia.
  • What does the public inspection record show, including FDA Form 483 observations, warning letters, and recalls?
  • Does it provide a certificate of analysis by lot, with sterility and endotoxin testing for sterile products?
  • How does it set beyond-use dates, and what stability data support them?
  • Are its prices published, and the same for every practice?
  • How fast does it notify practices of recalls and quality issues?

The rules change

Ingredient lists and interim policies change. On October 14, 2026, FDA submitted a notice to the White House Office of Management and Budget for review, RIN 0910-ZD94. As of October 20, 2026, it had not been published. Recheck the status of anything the practice offers before launch and on a set schedule. Do not tell patients that a pending policy has already made something available.

How SiriusRx helps

The SiriusRx Peptide Program teaches these pathways to clinicians and staff, records which pathway each practice uses at onboarding, and shares information on independent partner pharmacies that meet published quality standards. Vetting is information, not a warranty. The prescriber and the patient choose the pharmacy. SiriusRx does not take payment from a pharmacy.

General education, not legal advice.

Sources

  • FD&C Act section 503A, 21 U.S.C. 353a: https://www.law.cornell.edu/uscode/text/21/353a.
  • FD&C Act section 503B, 21 U.S.C. 353b: https://www.law.cornell.edu/uscode/text/21/353b.
  • FDA, Compounding and the FDA: Questions and Answers: https://www.fda.gov/drugs/human-drug-compounding/compounding-and-fda-questions-and-answers.
  • FDA, bulk drug substances under section 503A of the FD&C Act.
  • FDA, bulk drug substances under section 503B of the FD&C Act.
  • FDA guidance for industry (January 2025) on the interim bulk-substance policy under section 503B: https://www.fda.gov/media/94402/download.
  • FDA guidance for industry (January 2018) on essentially copies of a commercially available drug product under section 503A: https://www.fda.gov/media/98973/download.
  • 21 CFR 310.305, records and reports concerning adverse drug experiences: https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-310/subpart-E/section-310.305.
  • FDA, Registered Outsourcing Facilities: https://www.fda.gov/drugs/human-drug-compounding/registered-outsourcing-facilities.
  • FDA, inspection findings, recalls, and other actions: https://www.fda.gov/drugs/human-drug-compounding/compounding-inspections-recalls-and-other-actions.
  • USP compounding standards: https://www.usp.org/compounding.
  • Va. Code 54.1-3410.2, Compounding; pharmacists' responsibilities: https://law.lis.virginia.gov/vacode/title54.1/chapter34/section54.1-3410.2/.
  • Va. Code 54.1-3420.2, Delivery of prescription drug order: https://law.lis.virginia.gov/vacode/title54.1/chapter34/section54.1-3420.2/.
  • Va. Code 54.1-3434.1, nonresident pharmacies to register with the Board: https://law.lis.virginia.gov/vacode/title54.1/chapter34/section54.1-3434.1/.
  • 18VAC110-20-275, delivery of dispensed prescriptions: https://law.lis.virginia.gov/admincode/title18/agency110/chapter20/section275/.
  • OMB Office of Information and Regulatory Affairs, pending review, RIN 0910-ZD94: https://www.reginfo.gov/public/do/eoDetails?rrid=1568964.

For practices

Contact us.

This is education for licensed practices. It is not legal, medical, or pharmacy advice, and it does not tell a practice what to prescribe. Contact us with questions about the program.