FDA Warning Letter Signals Increased Scrutiny of the Medical Necessity Exception for Compounded GLP-1s
By Patrick O’Brien, JD, American Med Spa Association (AmSpa)
The FDA’s recent warning letter to Empower Pharmacy has drawn increased attention to the prescribing of compounded semaglutide or tirzepatide following the end of the FDA-declared shortages. While the letter addresses several issues, its most important takeaway for medical aesthetic practices is the FDA’s focus on the “significant difference” or “medical necessity” exception to the prohibition on compounding drugs that are essentially copies of commercially available products.
In general, pharmacies are not permitted to compound versions of drugs that are essentially copies of FDA-approved products unless an exception exists. Federal law contains a limited exception when a prescribing practitioner determines that a change to the compounded medication produces a significant difference for an identified patient.
The Empower warning letter suggests the FDA is closely examining how this exception is being used in practice. According to the agency, investigators found prescriptions that either lacked a documented determination of significant difference or contained nearly identical statements repeated across numerous prescriptions. The FDA also expressed concern about technology platforms that provide providers with pre-selected options for documenting a significant difference.
This is important because it reinforces a point that is often misunderstood: the medical necessity exception is patient specific and has defined elements that need to be met in order to utilize it. It is not a blanket authorization to compound GLP-1s.
The warning letter also calls into question a common assumption that adding ingredients such as B12, cyanocobalamin, niacinamide, or similar substances automatically creates a qualifying difference. The FDA specifically identified compounded semaglutide/cyanocobalamin and tirzepatide/niacinamide products and suggested that the volume of prescriptions and nature of the purported differences raised concerns about whether the modifications were truly individualized.
The key issue is not whether a product has been modified. The key issue is whether the modification is necessary for a particular patient. For example, a patient may require a compounded formulation because of an allergy to an ingredient in the commercially available product or because the approved formulation cannot be administered in a way that meets the patient’s needs. In each case, the rationale must be tied to the individual patient rather than a broader patient population.
Providers should also remember that cost alone is generally not sufficient to justify use of the exception. While patients understandably seek lower-cost treatment options, the significant-difference exception is intended to address patient-specific medical needs, not affordability concerns.
From the FDA’s message, it appears that they do not take a claim of a medical necessity at face value and are likely to scrutinize whether that determination reflects genuine, individualized clinical judgment. Providers who continue to prescribe compounded GLP-1 medications should ensure that their documentation is patient specific, medically supported, and capable of withstanding regulatory review.
As FDA scrutiny of compounding practices continues to evolve, providers should stay informed about regulatory developments that may affect their operations. AmSpa Members receive access to legal and regulatory resources, compliance tools, and expert guidance designed to help medical aesthetic practices navigate complex issues such as compounded medications, scope of practice, and evolving FDA enforcement priorities.
