New light shed on who benefits most from weight-loss jabs
New light shed on who benefits most from weight-loss jabs
A recent study suggests that individuals with specific genetic variations may achieve greater weight loss when using medications like Wegovy and Mounjaro. Researchers analyzing data from 15,000 participants found that these genetic differences could explain why some people experience significant weight reduction while others see minimal results. Side effects such as nausea and vomiting also appear to vary depending on the presence of these genetic traits.
Drug mechanisms and genetic links
Weight-loss drugs like Wegovy and Mounjaro work by mimicking natural gut hormones that suppress hunger and increase satiety. The study, published in the Nature journal, highlights that variations in two genes connected to appetite and digestion might influence how effectively these drugs perform. While genetics may contribute to individual differences, other factors—such as age, sex, and geographic origin—also play a role, according to experts.
Approximately 1.6 million people in the UK have used weight-loss medications in the last 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 conditions. Weight loss percentages differ widely among users, with trials showing up to 20% loss on tirzepatide (Mounjaro) and 14% on semaglutide (Ozempic and Wegovy).
Analysis of genetic data from 23andMe revealed patterns linking certain variants to drug effectiveness. Professor Ruth Loos, from the University of Copenhagen, noted that a specific genetic variant is associated with both greater weight loss and increased nausea. “People lose more weight if they have this variant,” she stated in a
blockquote>. “The extra weight lost amounts to about 0.76kg on average, but those with two copies of the gene can double that benefit.”
The variant is more common in people of European descent, with 64% carrying one copy and 16% having two. In contrast, only 7% of African Americans have one copy. Dr Marie Spreckley, a metabolic expert from the University of Cambridge, emphasized that genetics is just one aspect of a broader picture. “The main drivers of outcomes are behavioural, clinical, and treatment-related factors,” she explained.
Side effects and future implications
Another genetic variant identified in the study may contribute to severe side effects, such as vomiting, when taking tirzepatide. This could mean up to 1% of users experience nausea 15 times worse than typical. While the genetic effect is modest, Prof Loos called it “not trivial” and comparable to other influencing factors.
Professor Naveed Sattar from the University of Glasgow added that the findings, though scientifically intriguing, are not yet sufficient to alter clinical practices. “More robust trial data is needed to understand the full balance of benefits and risks,” he said.
The research hints at the potential for precision medicine, where genetic and other patient data could guide treatment choices. However, experts caution that such applications are still in development. “This is a promising step, but we’re not there yet,” remarked Prof Sattar, highlighting the need for further validation across studies.