Jennifer, a 57-year-old attorney, began using the GLP-1 medication Mounjaro in 2023 and lost 40 kilograms (88 pounds). The drug, originally developed for type 2 diabetes, is now used by millions for weight loss. She reports that while her weight has improved, her 30-year marriage has experienced new challenges. GLP-1 receptor agonists regulate blood sugar, slow digestion and reduce appetite. Prescriptions have risen sharply, with Australian use increasing almost tenfold since 2020 and U.S. use more than quadrupling. Known physical side effects include nausea, vomiting, diarrhea and constipation. Some patients in online support groups report changes in sexual desire and function. A 2025 analysis of FDA data identified 185 reports of sexual dysfunction, mainly among men using GLP-1 receptor agonists. A 2025 Kinsey survey found 18% of respondents indicated increased desire and 16% reported decreased desire. Dr Terri-Lynne South, a general practitioner specializing in obesity medicine, said GLP-1s may influence dopamine pathways that affect reward seeking for substances and potentially sexual drive. Dr Mark Mellor, a bariatric physician, noted that heightened self‑confidence after weight loss could lead individuals to question their relationship satisfaction. A 2018 Swedish study of 1,958 bariatric surgery patients found higher rates of divorce or separation among couples and more frequent formation of new relationships among singles. Psychologist Glenn Mackintosh of the Weight Management Psychology Clinic said that major weight loss can disrupt established relationship routines, creating a grieving process. Experts suggest that weight loss does not cause relationship problems but can reveal pre‑existing issues, which may be addressed through communication and therapy. Jennifer’s husband asked for couples therapy after 34 years of marriage, noting that she became less physically demonstrative and more critical. She said she now holds her partner to a higher standard and is unsure whether the medication altered their marriage or simply removed a long‑standing explanation for their difficulties. She plans to continue the medication indefinitely. Jennifer said she expects to remain on the drug for life and that she and her spouse will adapt to the changes, though the future remains uncertain.