Understanding Compounded Medications

Compounded medication is one of the least well understood parts of telehealth, and the confusion is not accidental. A great deal of marketing works by leaving the impression that a compounded preparation is the same product as a brand-name drug, obtained more cheaply. It is not, and understanding why puts you in a much better position to ask useful questions.

What compounding actually is

Compounding is the preparation of a medication by a pharmacist for a specific patient, against a prescription, in a form that is not commercially available. It is an old practice and a legitimate one. A child who cannot swallow a tablet may need a liquid the manufacturer does not make. A patient allergic to a dye or preservative may need the same active ingredient without it. A dose may be needed that falls between the strengths that are manufactured. The defining feature is that the preparation is made for an identified individual on the instruction of a prescriber who has determined that a commercially available product will not do.

503A and 503B

Two categories of facility do this work, and the distinction matters. 503A pharmacies are traditional compounding pharmacies, licensed by state boards of pharmacy. They compound for identified individual patients against a prescription. They are not registered with the FDA as manufacturers, and their preparations are not subject to FDA approval or to the manufacturing standards that apply to approved drug products. 503B outsourcing facilities are a category created by the Drug Quality and Security Act of 2013, following the 2012 fungal meningitis outbreak traced to a Massachusetts compounding pharmacy. They register with the FDA, are subject to FDA inspection, must comply with current good manufacturing practice, and may compound in batches without patient-specific prescriptions. They are more heavily regulated than 503A pharmacies and less heavily regulated than drug manufacturers. Neither category produces FDA-approved drugs. That phrase means something specific: that a manufacturer submitted an application containing clinical trial data, that the FDA reviewed it, and that the agency concluded the product's benefits outweigh its risks for a stated indication in a stated population. Compounded preparations do not go through that process.

What FDA oversight does and does not cover

For an approved product, the FDA has reviewed the clinical evidence, approved the labelling, approved the manufacturing process and the facility, and continues to monitor adverse events through a formal system. Every batch is made to a specification the agency has seen. For a compounded preparation, none of that applies. The FDA does regulate the categories of bulk substance that may be compounded, and it maintains lists of substances that present significant safety risks. It inspects 503B facilities and can inspect 503A pharmacies. But it has not reviewed the specific preparation you receive for safety or effectiveness, and there is no approved labelling for it. This is not an argument that compounded medications should not be used. It is an argument that the difference should be stated plainly rather than obscured, because it changes what you can reasonably assume.

Why compounded GLP-1 preparations became widespread

When a drug is on the FDA's shortage list, compounding of a copy is permitted under conditions that do not otherwise apply. Semaglutide and tirzepatide spent extended periods on that list, and a substantial compounding market grew during it. When the FDA declared those shortages resolved, the legal basis for straightforward copying narrowed considerably, and the market shifted toward preparations argued to be clinically different from the approved products — different concentrations, combinations with other substances, or alternative routes. Whether any given preparation genuinely meets the standard for compounding rather than copying is a regulatory question that has been contested in litigation. It is worth knowing that the ground here has moved repeatedly and may move again.

Questions worth asking

• Which pharmacy is dispensing this, and is it a 503A pharmacy or a 503B outsourcing facility?
• Is it licensed in my state?
• What is in the preparation besides the active ingredient?
• Has the finished preparation been tested, and by whom?
• What is the beyond-use date, and how should it be stored?
• What happens if I have an adverse reaction — who do I report it to?

A service that answers these readily is telling you something. So is one that does not.

What to be sceptical of

Language that implies equivalence with an approved product — "the same as", "generic", "identical to" — is the clearest signal that someone is managing your impression rather than informing you. Generic has a precise regulatory meaning: a product approved through an abbreviated pathway on a demonstration of bioequivalence to a reference product. No compounded preparation is a generic. Be equally cautious of preparations that combine an active ingredient with additional substances positioned as enhancements. Each addition is another variable, and combinations are rarely supported by the evidence base that exists for the ingredient on its own.

The reasonable position

Compounded medication has real clinical uses, and for some patients it is the right answer. The reasonable position is neither that it is interchangeable with an approved product nor that it is inherently unsafe. It is that it is a different thing, made under a different framework, with a different evidence base — and that you are entitled to know that before you decide.