GLP-1 weight-loss drugs reach millions, with early hints at wider effects

As GLP-1 use scales, researchers are probing effects beyond weight — on sexual function and relationships — though evidence is thin.

GLP-1 drugs such as Mounjaro, originally designed to manage type 2 diabetes by regulating blood sugar, slowing digestion and curbing appetite, are now used by millions worldwide for weight loss. Australian prescriptions have risen almost tenfold since 2020, and US use has more than quadrupled. One profiled patient, a 57-year-old who started Mounjaro in 2023, lost 40kg over three years.

The scale of uptake is bending a large chronic-disease burden, and researchers are beginning to track knock-on effects. A 2025 analysis of US FDA data identified 185 reports of sexual dysfunction, particularly among men taking GLP-1 receptor agonists. A 2025 Kinsey study found 18 percent of respondents reported increased sexual desire on the drugs while 16 percent reported decreased desire. A 2018 Swedish study of 1,958 bariatric surgery patients found higher rates of divorce or separation among couples and more new relationships among singles.

For health abundance, cheap and effective treatment of obesity and diabetes at population scale is the headline: these are among the most common and costly chronic conditions. The secondary effects on mood, appetite for alcohol and nicotine, and relationships are a reminder that a drug reshaping millions of bodies also reshapes lives around them.

The caveats are substantial. Evidence on sexual function is limited and mixed, effects on relationships are poorly researched, and doctors say it is hard to separate the drug's action from weight loss itself. Some accounts come from Reddit and Facebook support groups, and the individual case rests on anecdote.

Source: Guardian