Semaglutide (Ozempic) raises questions about mood and nonresponse

2. Separate pharmacogenomic data suggest that variants in the peptidylglycine alpha-amidating monooxygenase gene may reduce response to some glucagon-like peptide-1 receptor agonists in about 10% of the population.

Clinicians are increasingly hearing patients describe emotional flatness, reduced libido, or less interest in activities they previously enjoyed while taking glucagon-like peptide-1 (GLP-1) receptor agonists. The cultural shorthand has become “Ozempic personality,” a phrase popularized in part by Washington Post reporting on patients who described life feeling less rewarding on these medications. The pattern is not the same as major depressive disorder, but some clinicians have described it as a mild anhedonia-like state. Mechanistically, the concern is plausible because GLP-1 pathways interact with central reward circuits, including dopamine signaling. Novo Nordisk has studied semaglutide (Ozempic) in more than 54,000 participants, and anhedonia is not currently listed as an adverse drug reaction or warning in prescribing information. Eli Lilly has similarly stated that it has no data to share on anhedonia in tirzepatide (Mounjaro) users. That does not prove the effect is absent, but it does mean the signal remains clinically unsettled. A separate body of research is adding another layer to the GLP-1 story by focusing on nonresponse. Stanford Medicine reported that variants in the peptidylglycine alpha-amidating monooxygenase (PAM) gene, carried by roughly 10% of the population, may reduce the ability of GLP-1 drugs to regulate blood sugar. The Stanford Medicine summary described the work as a potential explanation for GLP-1 resistance, with the study published in Genome Medicine. In these patients, endogenous GLP-1 levels may be normal or elevated, but downstream signaling appears blunted. That could help explain why some patients plateau despite appropriate dosing, adherence, and lifestyle effort. The distinction is clinically useful: one patient may be experiencing central reward-related adverse effects, while another may have a pharmacogenomic reason for limited metabolic response. Tirzepatide may partially bypass this problem because it also activates the glucose-dependent insulinotropic polypeptide (GIP) receptor, although this remains an evolving area. For now, the practical approach is careful symptom tracking, nonjudgmental discussion of mood and reward changes, and recognition that lack of response should not automatically be framed as poor adherence.