New light shed on who benefits most from weight-loss jabs
New light shed on who benefits most from weight-loss jabs
Research indicates that individuals with specific genetic variations related to appetite and digestion may experience greater weight loss when using medications like Wegovy and Mounjaro. A study published in the Nature journal highlights this connection, offering insights into why some people achieve significant results while others see minimal impact. These drugs work by slowing digestion and reducing hunger, mimicking a natural gut hormone that promotes satiety.
Genetic Variations Linked to Weight Loss Outcomes
The study analyzed genetic data from 15,000 people who had enrolled in gene-testing programs through 23andMe. By examining millions of genetic markers, researchers identified patterns suggesting a correlation between certain variants and the effectiveness of weight-loss treatments. Professor Ruth Loos, from the University of Copenhagen, noted that one variant is associated with both weight loss and nausea. “People who have this variant tend to lose more weight,” she explained. Those with two copies of the gene could see an average of 0.76kg (1.6 lbs) additional loss, compared to individuals with only one copy.
“The genetic effect, while modest, is similar to other factors—and not trivial,” said Prof Loos. “However, the findings need to be confirmed in further studies, as current research has not consistently replicated these links.”
The same genetic variant was also found to be linked to severe side effects, such as vomiting, in those taking tirzepatide (Mounjaro). This could mean up to 1% of users experience vomiting that is 15 times more intense than typical. Meanwhile, another genetic factor appears to influence the severity of these side effects.
Additional Influencing Factors
Dr Marie Spreckley from the University of Cambridge emphasized that genetics is just one element in a broader picture. “The main drivers of outcomes are behavioural, clinical, and treatment-related factors,” she said. This includes lifestyle choices like exercise and diet, the level of support received, and pre-existing health conditions. Other variables, such as sex, age, and ethnicity, also play a role. For example, women are more than twice as likely as men to lose 15% of their body weight on Mounjaro, though the exact reasons remain unclear.
Factors like the type of medication, dosage, and treatment duration have all been tied to greater weight reduction. In the UK, it is estimated that at least 1.6 million people have used weight-loss drugs in the past year, with most purchasing them privately through online pharmacies. The NHS provides Wegovy and Mounjaro to only a small group of patients with severe obesity and related health concerns.
Implications for Future Treatments
Combining genetic data with other patient information could one day enable personalized treatment plans, a concept known as precision medicine. However, Professor Naveed Sattar, a metabolic health expert from the University of Glasgow, cautioned that “these findings are scientifically interesting but far from changing clinical practice.” He stressed the need for more comprehensive trial data to better understand the trade-offs between benefits and risks of such therapies.
