How a 503A compounding pharmacy works

General information, not medical or legal advice. Updated October 2026.

Quick answer A 503A pharmacy is a state-licensed pharmacy that prepares a medicine for one identified patient, on a prescription, under section 503A of the federal Food, Drug, and Cosmetic Act. If a provider prescribes you a compounded medicine, this is most likely the kind of pharmacy that makes it. Compounded medicines are not FDA-approved, so the pharmacy's licence and standards are what you check, and the questions below are what to ask.

What is compounding?

Compounding is a pharmacist combining, mixing or adjusting ingredients to make a medicine for a particular patient. FDA gives two examples of why someone might need one: a person with an allergy to a dye in a tablet who needs the medicine made without it, or someone who can't swallow a tablet and needs a liquid.

The key word is patient. A manufacturer makes large runs of identical units; a 503A pharmacy prepares a medicine for one person on a prescription.

What rules does a 503A pharmacy follow?

Section 503A exempts a compounded drug from three requirements that apply to manufactured drugs (FDA approval before marketing, current good manufacturing practice or CGMP, and labeling with adequate directions for use) if it meets these conditions:

• A prescription for an identified patient. Compounding happens on a valid prescription, or in limited quantities before one, based on a history of prescriptions from an established relationship.
• A licensed pharmacist or physician. A licensed pharmacist in a state-licensed pharmacy or federal facility, or a licensed physician, does the work.
• Allowed ingredients only, in a set order. If a USP or NF monograph (an official quality standard) exists for a bulk ingredient, the ingredient has to meet it. If none exists, it must be a component of an FDA-approved drug. If neither applies, it must be on FDA's 503A bulks list, a federal regulation (21 CFR 216.23). Every bulk ingredient also needs a valid certificate of analysis and has to come from an FDA-registered establishment.
• No routine copies. A pharmacy may not regularly, or in inordinate amounts, compound drugs that are essentially copies of a commercially available drug. A change the prescriber determines makes a significant difference for an identified patient is not a copy (FDA explains this limit in January 2018 guidance).
• Some drugs are off limits. A pharmacy can't compound a drug on FDA's list of products withdrawn or removed from the market as unsafe or ineffective, or one FDA has identified by regulation as presenting demonstrable difficulties for compounding.
• Limits on shipping across state lines. The law caps how much a pharmacy may distribute out of state, depending on whether its state has signed a memorandum of understanding with FDA.

State boards of pharmacy have primary responsibility for the day-to-day oversight of state-licensed pharmacies, and FDA also conducts surveillance and for-cause inspections. USP's compounding chapters are the working standards: chapter 795 for non-sterile preparations and chapter 797 for sterile ones such as injections. Revised versions of both became official on November 1, 2023.

How is a 503A pharmacy different from a 503B outsourcing facility?

The Drug Quality and Security Act, enacted on November 27, 2013, created a second category, the 503B outsourcing facility. A facility becomes one by electing to register with FDA, and the law defines it as a facility that compounds sterile drugs and meets all of section 503B's requirements.

Neither makes FDA-approved drugs: they are two compounding routes with different oversight.

What does "compounded" not mean?

It doesn't mean FDA-approved, and it doesn't describe a product sold online as "research use only". That isn't compounded at all: no licensed pharmacy made it for a patient, and it sits outside these rules.

What should you ask before you start?

Everlon is not a pharmacy and does not prepare or dispense medication. When a provider prescribes a compounded treatment through Everlon, a state-licensed 503A compounding pharmacy prepares it, and the pharmacy that fills your prescription is named on the label. Ask any provider or pharmacy, including ours:

1. Which pharmacy will fill my prescription, and is it licensed in the state where I live?
2. Is it a 503A pharmacy or a 503B outsourcing facility?
3. Who do I contact if I have a side effect or a problem with my order?
4. Will a licensed provider review my health history before anything is prescribed, and can that provider say no?

You can check a pharmacy's licence yourself: FDA's BeSafeRx page links to each state board of pharmacy's licence lookup, and FDA says not to use a pharmacy that isn't listed. See how Everlon handles pharmacies and quality.

Is this right for me?

Online care with a compounded medicine is usually considered by adults who:

• want a treatment a provider can prescribe as a compounded medicine, and accept that it is not FDA-approved;
• can give a full, honest health history and medication list online.

In-person care is usually the better route if you need a hands-on exam, close in-person monitoring, or help with something urgent.

An independent licensed provider in your state reviews your health history, medications and goals and decides whether any treatment is appropriate. The answer may be no.

How it works

1. Answer a short health review. Your state is confirmed first, before you share any health information. Then you answer questions about your health, medications and goals.
2. A licensed provider in your state decides. An independent licensed provider reviews your answers and decides, and can decline. You'll be notified when they respond. You'll only be charged if treatment is prescribed.
3. A licensed U.S. pharmacy prepares and ships it. If it's prescribed, a licensed U.S. pharmacy prepares it for you and it ships to your door, with standard shipping included. GLP-1 plans are billed every 4 weeks; NAD+, sermorelin, glutathione and GHK-Cu plans every 30 days.

See the full process on how it works.

FAQ

Are compounded medications FDA-approved? No. FDA does not approve compounded drugs or verify their safety, effectiveness or quality before they are marketed.

Can a 503A pharmacy compound any ingredient a provider asks for? No. The ingredient has to follow the sequence above: a USP or NF monograph if one exists, otherwise a component of an FDA-approved drug, otherwise the 503A bulks list. That is why some peptides can't be compounded.

Is a compounded drug an FDA-approved version of a brand-name drug? No. FDA says a drug approved under section 505(j) has to establish therapeutic equivalence to a brand-name drug, among other requirements, while a compounded drug is not approved by FDA at all.

How can I check a pharmacy is licensed? Use FDA's BeSafeRx state-by-state links to the board of pharmacy licence databases. FDA says that if the pharmacy isn't listed there, you should not use it.

Safety information

Compounded medications are not FDA-approved. FDA does not verify their safety, effectiveness or quality before they are marketed, and it warns that poor compounding practices can cause contamination or a drug with too much or too little active ingredient. Your provider will go over the risks of anything they prescribe.

• Tell your provider everything: every medicine and supplement you take, and every condition you have.
• Read your label. It names the pharmacy and gives your instructions. Don't change how you use a medicine on your own.
• Avoid "research use only" products. They aren't made by a licensed pharmacy for a patient and carry additional dangers.
• Report serious problems. You or your provider can report a serious problem with a medicine to FDA's MedWatch program, which takes reports from patients and consumers as well as health professionals.

If this is a medical emergency, call 911. For side effects or anything that doesn't seem right, contact your provider and email care@everlon.health.

Sources

• 21 U.S.C. 353a, Pharmacy compounding. law.cornell.edu, accessed 2026-10-13
• FDA. FD&C Act Provisions that Apply to Human Drug Compounding. fda.gov, accessed 2026-10-13
• FDA. Human Drug Compounding Laws. fda.gov, accessed 2026-10-13
• FDA. Information for Outsourcing Facilities. fda.gov, accessed 2026-10-13
• FDA. Compounding and the FDA: Questions and Answers (content current as of 09/16/2025). fda.gov, accessed 2026-10-13
• FDA. Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act. fda.gov, accessed 2026-10-13
• FDA. Prescription Requirement Under Section 503A of the Federal Food, Drug, and Cosmetic Act (guidance for industry). December 2016. fda.gov, accessed 2026-10-13
• FDA. Compounded Drug Products That Are Essentially Copies of a Commercially Available Drug Product Under Section 503A of the Federal Food, Drug, and Cosmetic Act (guidance for industry). January 2018. fda.gov, accessed 2026-10-13
• 21 CFR 216.23, Bulk drug substances that can be used to compound drug products in accordance with section 503A. ecfr.gov, accessed 2026-10-13
• National Association of Boards of Pharmacy. NABP's compounding pharmacy accreditation shows your pharmacy's alignment to USP standards (USP <795> and <797> became official November 1, 2023). nabp.pharmacy, accessed 2026-10-13
• FDA. BeSafeRx: Considering an Online Pharmacy? fda.gov, accessed 2026-10-13
• FDA. BeSafeRx: Locate a State-Licensed Online Pharmacy. fda.gov, accessed 2026-10-13
• FDA. MedWatch: The FDA Safety Information and Adverse Event Reporting Program (content current as of 10/09/2026). fda.gov, accessed 2026-10-13

This article is general information, not medical or legal advice. Compounded medications are not FDA-approved. Talk with a licensed provider about whether any treatment is right for you.