Why a compounded drug is never FDA-approved

What does approval actually mean?

A decision about one specific product made by one specific applicant.

FDA approval attaches to a drug product with a defined formulation, manufacturing process, labelling and applicant, after review of an application containing the evidence supporting it. It is not a property of a molecule, and it does not travel to a different preparation containing the same active pharmaceutical ingredient. That is why an approved product and a compounded preparation of the same active ingredient are two different regulatory objects even when a clinician would describe them in the same words.

Compounded preparations have no such application and no such review. That is not an omission in the system; it is how the system is built, and the next section is why.

Why is this structural rather than a gap?

Because the provisions that permit compounding are worded as exemptions from the approval requirement.

Section 353a(a) of Title 21 exempts a compounded drug from three requirements of the Federal Food, Drug, and Cosmetic Act — current good manufacturing practice at § 501(a)(2)(B), adequate directions for use at § 502(f)(1), and new drug approval at § 505 — where stated conditions are met. Section 353b(a) does the same for drugs compounded by a facility registered as an outsourcing facility, exempting them from § 502(f)(1) and § 505, though not from the manufacturing-practice requirement.

Read that carefully and the point is unavoidable. The statute permits the preparation by relieving it of the approval requirement. A preparation that had been approved would not need the exemption, and a preparation relying on the exemption has by definition not been approved. The two are alternatives.

Does FDA say so itself?

Yes, and in one place it is codified rather than merely stated in guidance.

The regulation listing bulk drug substances usable under section 503A carries this in its own text:

Any person who represents that a compounded drug made with a bulk drug substance that appears on this list is FDA approved, or otherwise endorsed by FDA generally or for a particular indication, will cause the drug to be misbranded under section 502(a) and/or 502(bb) of the Federal Food, Drug, and Cosmetic Act.

The same paragraph records that, on the evidence available, there are inadequate data to demonstrate safety or efficacy for products compounded with those substances, or to establish general recognition of either. This is not a labelling nicety. Misbranding is an enforcement theory, and the regulation names the representation that triggers it.

What about the pharmacy or the facility?

Neither one is approved either, and the two entity types are credentialed by different bodies — which is where most of the confusion in this market originates.

A 503A pharmacy is licensed by a state board of pharmacy. A 503B outsourcing facility registers with FDA under section 503B, must comply with current good manufacturing practice, and is subject to FDA inspection on a risk-based schedule. Registration is a filing that creates obligations; it is not a finding that anything was reviewed and accepted. FDA states plainly, in its guidance addressed to telehealth companies promoting compounded drugs, that it does not approve or license any such facility.

So the phrase that circulates in this market is wrong twice over: it attaches a status FDA does not confer to an entity FDA does not confer it on. The safe construction, and the accurate one, is "registered with FDA as an outsourcing facility under section 503B."

Does an enforcement category change the answer?

No, and this is the most sophisticated version of the same mistake.

FDA operates an interim policy that sorts nominated bulk drug substances into categories while rulemaking is pending. A category 1 placement means the agency does not intend to take action against a compounder using that substance, provided the conditions in the guidance are met. That is a statement about the agency's enforcement intentions, revocable, and it decides nothing about approval, safety or effectiveness.

Two further details make the distinction worth stating precisely. The categories are separate objects from the statutory bulk drug substance lists, which are short and set by regulation — conflating the two is how a category placement gets reported as though a substance had been added to a list, and it is the gap the circulating misreadings of the 2026 events grew in. And FDA has said it does not intend to place substances nominated on or after 7 January 2025 into these categories at all, so the categories are a closing interim arrangement rather than a route to anything.

What can be said accurately?

Quite a lot, and the accurate statements are more useful to a prescriber than the inaccurate one.

Why does this matter to a prescriber?

Because a supplier's vocabulary is diagnostic, and it is one of the few things you can check in a first conversation.

A supplier that reaches for approval language about a compounded preparation is either mistaken about the framework it operates in or comfortable describing it inaccurately, and neither reading is reassuring. The questions that do have real answers are which entity type will compound the preparation, under which statutory pathway, and what state credentials that entity holds where you practise.

Those are set out at 503A pharmacies and 503B outsourcing facilities compared, and the condition that decides which pathway is even available is covered at the patient-specific prescription requirement. If the practical question behind yours is whether your own practice may hold stock, that is a state question, answered state by state in the office-use guide.