Key Considerations for "Microdosing" of Obesity Medications

A "perspective statement" by an OMA working group focuses on the use of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) at doses much lower than those studied and FDA-approved -- i.e., commonly termed "microdosing." The statement recognizes the growing interest in such microdosing among prescribers and patients and aims to clarify the definitions and safety of this practice.

Patients are urged to evaluate the rationale for receiving a GLP-1 prescription at a dose that clinical trials have not studied or proven effective for obesity and other indications. We know that historically prescribers often modify doses of medications on an individual basis due to patient response or tolerance to medication, but starting a prescription medication at an unstudied dose has little validity outside of marketing or commercial tactics. When "microdosing" a GLP-1 medication, therefore, the physician and patient should have a clear reason for this practice.

The statement authors recognize that prescribing doses smaller than those studied may lower the drug cost or reduce gastrointestinal side effects, but the "human cost" of not deriving meaningful benefits from the drug due to substandard dosing is also a recognized real risk.

Another word of caution for patients is to check if the microdosed medication is from a compounding pharmacy rather than from an FDA-approved medication source. The authors remind us that the American Diabetes Association, The Obesity Society, the Obesity Action Coalition, and OMA have all issued statements against the use of compounded GLP-1 medications due to concerns about their safety, quality, and effectiveness.

Another caution noted is the need to use a syringe system to self-administer microdosed medication. In clinical trials of GLP-1 agonists, pen injectors were rigorously studied for accuracy and reproducibility of dose delivery. Using a syringe system can be challenging, and subtherapeutic dosing may lead to inadequate efficacy. Transferring the medication from a vial to a syringe introduces the risk of dosing errors and cleanliness concerns.

Microdosing has not been studied in clinical trials. We lack long-term outcome data supporting its efficacy in treating obesity, diabetes, sleep apnea, or metabolic dysfunction-associated steatohepatitis, and we lack evidence of cardiovascular risk reduction.

Ethical prescription of all medications is crucial. The central focus should be patient benefit and lack of harm. The statement authors recognize that the practice of prescribing smaller doses of FDA-approved GLP-1 medication -- as a way to personalize care for patients intolerant to standard doses or who are "hyper-responders" -- may be a suitable approach. As in all instances of patient care, shared decision-making between the patient and prescriber is crucial.

Alina Elperin, MD
March 26, 2026