Genes linked to appetite affect weight-loss drug
Get the Health newsletter
Daily health & science — research, biotech, public health, the studies worth knowing. Free.
- Researchers analyzed data from 15,000 23andMe users on weight-loss drugs and found that genetic variants linked to appetite and digestion predict who loses more weight and who experiences worse side effects like nausea and vomiting.
- Participants lost an average of 11.7% of body weight over roughly eight months, with outcomes ranging from near-zero to 30% — a gap the study attributes in part to two specific gene variants.
- One appetite-linked variant was associated with both greater weight loss and more nausea; carriers lost about 0.76 kg (1.6 lbs) more on average, and people with two copies could roughly double that extra loss.
- The variant's prevalence varies sharply by ancestry — 64% of people with European ancestry carry one copy and 16% carry two, compared to just 7% of African Americans carrying a copy, according to Prof Ruth Loos of the University of Copenhagen.
- A second variant flagged up to 1% of tirzepatide (Mounjaro) users as likely to experience vomiting roughly 15 times worse than typical for the drug, potentially guiding who should avoid it.
- Experts including Dr Marie Spreckley of the University of Cambridge and Prof Naveed Sattar of the University of Glasgow cautioned that genetics is only one factor alongside sex, age, ethnicity, dose and behaviour, and that the findings are 'a long way from changing clinical practice.'
- At least 1.6 million people in the UK are estimated to have tried weight-loss drugs in the past year, most buying them privately through online pharmacies since the NHS restricts Wegovy and Mounjaro to a small subset of obesity patients.
Why it matters: With at least 1.6 million people in the UK alone now using these drugs privately, even a modest genetic effect — roughly 0.76 kg of extra weight loss per variant copy — could meaningfully shape which patients clinicians eventually steer toward Wegovy, Mounjaro or alternatives once precision-medicine tools mature, though experts say that reality is years away and behavior, dose and other factors still dominate outcomes.
Ask SkimNews
