Millions of people worldwide are turning to GLP-1 (glucagon-like peptide-1) medications for weight loss, a treatment initially developed to manage type 2 diabetes. But as the numbers on the scales drop, some users are finding that their romantic relationships and intimacy take an unexpected hit.
While doctors often brief patients about common physical side effects like nausea, vomiting, diarrhoea, and constipation, the potential psychological and relational shifts brought about by GLP-1s are less frequently discussed. Anecdotal evidence from online forums and support groups suggests that some individuals using these medications have experienced changes in desire, sexual function, and emotional connection within their relationships.
Early scientific inquiry indicates that GLP-1s might be influencing more than just hunger. According to Dr. Terri-Lynne South, a general practitioner specialising in obesity medicine, the impact on the brain's dopamine reward pathways could play a unique role: reducing pleasure-seeking behaviours related to alcohol and nicotine, and potentially affecting sex drives too. However, evidence regarding altered sexual function remains limited and somewhat mixed – some studies hint at improved testosterone levels and benefits for sexual health, but others point to 185 reports of sexual dysfunction among men taking GLP-1 receptor agonists, as identified in a 2025 US Food and Drug Administration analysis.
Research is shedding light on varied experiences. The 2025 Kinsey study found that 18% of respondents on GLP-1s reported an increase in sexual desire, while 16% noted a decrease. Crucially, it's unclear whether these changes are directly caused by the medication or other factors such as significant weight loss or life changes like age or menopausal status. We know that rapid and substantial weight loss can put considerable pressure on relationships – a 2018 Swedish study found an increased incidence of divorce or separation among couples following bariatric surgery, alongside a higher likelihood of new relationships for those who were single.
Jennifer's story is a poignant example. After losing 40kg with Mounjaro in 2023, she has seen profound psychological and relational changes – while delighted with her weight loss, she now navigates unexpected challenges in her 30-year marriage. Her experience underscores the complex interplay between physical transformation, identity shifts, and relationship dynamics, leaving many to ponder the precise role of GLP-1 medications versus the broader effects of weight loss.