GLP-1 drugs linked to eating disorders, erectile dysfunction and relationship changes
New studies link GLP-1 drugs to eating disorders, erectile dysfunction and relationship changes, while Deloitte reports the drugs' market boom has lifted pharma R&D returns but created a concentration risk.
New research highlights potential side effects and social consequences of GLP-1 receptor agonists, including associations with eating disorders, erectile dysfunction and relationship changes. A US study published in JAMA Psychiatry found that around 30% of study participants with eating disorders reported lifetime GLP-1 use, compared with 15% observed in the general adult population.
Among participants in the JAMA Psychiatry study, GLP-1 use was highest among those with binge eating disorder (around 55% of 66 participants) and those with atypical anorexia nervosa (around 42% of 50 participants), and lowest among participants with anorexia nervosa (around 11% of 116 participants).
Separately, a target trial emulation using US health records (n=10,434), published in the Lancet eClinicalMedicine in April 2026, found that GLP-1 receptor agonist use was modestly associated with an increased rate of erectile dysfunction in men with type 2 diabetes mellitus, compared with those using dipeptidyl peptidase-4 inhibitors. The results were generally consistent across sensitivity analyses, subgroups and an external validation cohort, but the association was attenuated and no longer statistically significant after NCO calibration. The study authors said these observational findings may reflect residual or selection bias and do not establish causation.
The social effects of GLP-1 drugs have also drawn attention. Historical data from bariatric surgery patients show that the risk of divorce increases as weight drops, and previous studies found that patients who underwent bariatric surgery were twice as likely to get a divorce compared with the general population. A professor at the Institute of Health and Care Sciences in Sweden who studies weight loss and relationship status said weight loss itself may increase a sense of autonomy or confidence, potentially empowering individuals to leave unhealthy relationships. A 2013 study supported this 'relationship tension' theory, finding that when one partner loses significant weight while the other remains the same, it can lead to feelings of insecurity and criticism from the partner who did not change. Among single individuals, the likelihood of forming a new relationship also increases substantially after weight loss.
In the pharmaceutical industry, GLP-1 drugs have helped increase the return on investment in R&D for the third consecutive year, but reliance on these medicines is creating a 'bubble' effect, according to Deloitte's annual report Measuring the Return from Pharmaceutical Innovation. The forecast internal rate of return rose from 5.9% in 2024 to 7.0% in 2025. For the first time in 16 years of analysis, obesity drugs displaced oncology drugs as the largest contributor to a pharma company's pipeline value, now accounting for 25% of total forecast sales, compared with just 1% in 2022. When GLP-1 drugs are excluded from the analysis, R&D productivity is weaker, with a rate of return of just 2.9%.
The average cost to progress a drug from discovery to launch increased from $2.23 billion in 2024 to $2.671 billion in 2025, while average forecast peak sales rose to $598 million in 2025 from $510 million in 2024; without GLP-1s, average peak sales drops to $353 million. The report counted 108 'blockbuster' drugs in the pipeline, including 14 new additions, and noted that only 54 of these represent 9% of all drugs in advanced development yet are forecast to deliver around 70% of total projected sales. The value of drugs with novel mechanisms of action rose to 53% in 2025 from 35% in 2024, with GLP-1 drugs taking the largest share (60%) in this tier.