Interesting article:
https://www.theguardian.com/science/2026/sep/07/glp1s-weight-loss-drugs-cravings-non-responders
But other characteristics might do. “We know, for example, that age plays a role – so older people lose less weight. Sex plays a role – men lose less than women,” said Miras. “[And] people with type 2 diabetes lose less weight compared to people without.”
Studies have also suggested ancestry might have an impact, with the medications most effective in people of European ancestry, and least effective in people of African American ancestry.
Dr Mahesh Umapathysivam, an endocrinologist and clinical researcher at Adelaide University in Australia, said it was plausible that hormones could have an effect too.
“There is growing evidence that oestrogen alters GLP-1 response. We see that with the difference between male response and female response. Also, we know from some of the physiological studies that time of menstrual cycle also alters GLP-1 response,” he said.
“Finally, the use of menopausal hormone replacement therapy – which contains oestrogen – is associated with greater weight loss in semaglutide users.”
Then there is the matter of genetics. A recent study highlighted the potential role of a genetic variant that affects receptors in the brain upon which the drugs work.
“People carrying the genetic variant, we found lose about an extra 0.76kg (1.6 lbs) on average, and people who carry two copies of the variant double that,” said Adam Auton, vice-president of human genetics at the 23andMe Research Institute, and the senior author of the study.
“For people with two copies, this accounts for about 10% of the weight people might expect to lose on these medications.”