Researchers have found insights into why weight-loss injections may be more effective for some individuals than for others, linking genetics to varying outcomes.
Differences in two genes involved in gut hormone pathways, which influence appetite and digestion, could be responsible for the range of results and side effects experienced by users of glucagon-like peptide 1 (GLP1) medications.
The study, published in the journal Nature, highlights the potential for utilizing genetic data in future obesity treatment strategies.
GLP1 receptor agonists, like semaglutide (Wegovy) and tirzepatide (Mounjaro), act similarly to natural gut hormones. These medications regulate hunger, insulin secretion, and digestion and are popular among millions dealing with obesity. Yet, the reasons for differing weight-loss outcomes and varying side effects remain somewhat of a mystery.
A team from 23andMe delved into data from nearly 28,000 patients using GLP1 drugs. They discovered that one gene variant, rs10305420, correlated with slightly greater weight loss in carriers compared to non-carriers. Meanwhile, another variant, rs1800437, was linked to nausea and vomiting in those using tirzepatide, although it didn’t affect weight loss amounts.
These results imply that genetic variations may play a role in individual responses to weight-loss injections, but the overall influence of genetics appears to be limited.
Marie Spreckley, an obesity specialist at the University of Cambridge, commented on the research, noting that while the findings present reasonable evidence of genetic impact, the actual effect sizes are relatively small in clinical settings. She pointed out that non-genetic factors—like sex, type of medication, dosage, and length of treatment—account for a significantly larger share of the variance observed.
Spreckley added that although this study illuminates the complexities surrounding responses to GLP1 therapies, genetics is simply one piece of a much larger puzzle. Factors related to behavior, clinical conditions, and treatment specifics continue to be the key determinants of outcomes.
In summary, while this research marks a meaningful advancement in understanding treatment variability and hints at future personalized approaches, its findings suggest that the genetic influence is modest and does not yet warrant using genetic information to steer clinical decisions routinely.
