Why obesity drugs work better for some people: these genes hold clues

## Summary
Dozens of new obesity drugs are coming: these are the ones to watch To identify a possible genetic component of this response, the authors examined data from 23andMe participants who had answered questions about their use of obesity treatments, including which drug they had used, how long they used it for, how much weight they had lost and which side effects they had experienced. What the science says How anti-obesity drugs cause nausea: finding offers hope for better drugs Obesity drugs: huge study identifies new health risks Subjects Obesity Genetics Metabolism Latest on: Obesity Genetics Metabolism Genetics reveal why people respond differently to GLP-1 weight-loss drugs News & Views 08 APR 26 Can weight-loss pills replace injectables? What the science says News 17 MAR 26 ‘Baked, not fried’: five highlights from nutrition research Spotlight 12 MAR 26 Genetics reveal why people respond differently to GLP-1 weight-loss drugs News & Views 08 APR 26 Saturation editing of RNU4-2 reveals distinct dominant and recessive disorders Article 08 APR 26 Single-cell spatiotemporal dissection of the human maternal–fetal interface Article 08 APR 26 Why some cancer-fighting immune cells lose their strength inside tumours News 02 APR 26 Aversive learning hijacks a brain sugar sensor to consolidate memory Article 25 MAR 26 Strength persists after a mid-life course of obesity drugs Research Highlight 19 MAR 26 Jobs Associate or Senior Editor, Nature Title: Associate or Senior Editor, Nature Locations: Shanghai or Madrid – hybrid working model Closing Date: 21st April 2026 About Springer Natur... Shanghai (CN), Madrid Springer Nature Ltd Associate or Senior Editor, Scientific Reviews Job Title: Associate or Senior Editor, Scientific Reviews Locations: Shanghai or Beijing (hybrid) Application deadline: April 23rd, 2026 About Sp...

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A study of the varied response to obesity drugs harnessed data from people who used 23andMe DNA tests.
Credit: Tiffany Hagler-Geard/Bloomberg via Getty
Scientists have identified a set of genetic variants that could help to explain why responses to obesity drugs vary markedly from person to person
1
.
One variant is associated with greater weight loss from the powerful
GLP-1 medications
. Others are linked to an increased risk of
side effects such as nausea
. The findings, published today in
Nature
, come from a study of almost 28,000 users of
the DNA-testing service 23AndMe
who reported taking weight-loss drugs.
The large sample size makes the findings compelling, says Andrea Ganna, a health data scientist at the University of Helsinki. But the genetic effect on weight loss is relatively small. “I don't see this as something that clinicians are going to use” to inform their practice, he says.
Co-author Adam Auton, vice-president of human genetics at 23andMe Research Institute, a non-profit organization in Palo Alto, California, that offers a DNA-testing service of the same name, acknowledges that the association was modest. “There’s a number of factors that can influence weight loss, of which genetics is a subcomponent.” But he notes that the genetic association with side effects was more substantial.
Wide variation
Next-generation weight-loss drugs mimic natural hormones that influence appetite and metabolism. The obesity drug semaglutide, for example, mimics a hormone called glucagon-like peptide-1 (GLP-1), and
the drug tirzepatide
includes mimics of both GLP-1 and the hormone glucose-dependent insulinotropic polypeptide (GIP). In one study
2
, participants taking semaglutide lost an average of 10% of their body weight — but some lost more than 25%, and others lost almost none.
Dozens of new obesity drugs are coming: these are the ones to watch
To identify a possible genetic component of this response, the authors examined data from 23andMe participants who had answered questions about their use of obesity treatments, including which drug they had used, how long they used it for, how much weight they had lost and which side effects they had experienced. Researchers then analysed hundreds of thousands of genetic variants in the participants’ genomes to search for correlations with the drugs’ efficacy and side effects.
The authors found that people carrying one copy of a specific variant in the gene encoding the receptor for GLP-1 lost, on average, 0.76 kilograms more over a median of 8 months of treatment than did people who had no copies. People carrying two copies of the variant lost around 1.5 kilograms more.
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doi: https://doi.org/10.1038/d41586-026-01107-5
Read the related News & Views, ‘
Genetics reveal why effectsof GLP-1 drugs vary
’.
References
Su, Q. J.
et al.
Nature
https://doi.org/10.1038/s41586-026-10330-z (2026).
Article
Google Scholar
Ryan, D. H.
et al. Nature Med.
30
, 2049–2057 (2024).
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Subjects
Obesity
Genetics
Metabolism
Latest on:
Obesity
Genetics
Metabolism
Genetics reveal why people respond differently to GLP-1 weight-loss drugs
News & Views
08 APR 26
Can weight-loss pills replace injectables? What the science says
News
17 MAR 26
‘Baked, not fried’: five highlights from nutrition research
Spotlight
12 MAR 26
Genetics reveal why people respond differently to GLP-1 weight-loss drugs
News & Views
08 APR 26
Saturation editing of RNU4-2 reveals distinct dominant and recessive disorders
Article
08 APR 26
Single-cell spatiotemporal dissection of the human maternal–fetal interface
Article
08 APR 26
Why some cancer-fighting immune cells lose their strength inside tumours
News
02 APR 26
Aversive learning hijacks a brain sugar sensor to consolidate memory
Article
25 MAR 26
Strength persists after a mid-life course of obesity drugs
Research Highlight
19 MAR 26
Jobs
Associate or Senior Editor, Nature
Title: Associate or Senior Editor, Nature Locations: Shanghai or Madrid – hybrid working model Closing Date: 21st April 2026   About Springer Natur...
Shanghai (CN), Madrid
Springer Nature Ltd
Associate or Senior Editor, Scientific Reviews
Job Title: Associate or Senior Editor, Scientific Reviews Locations: Shanghai or Beijing (hybrid) Application deadline: April 23rd, 2026   About Sp...
Shanghai (CN) /Beijing
Springer Nature Ltd
Associate or Senior Editor, Commu

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## Expert Analysis

### Merits
N/A

### Areas for Consideration
- Others are linked to an increased risk of side effects such as nausea .

### Implications
- Credit: Tiffany Hagler-Geard/Bloomberg via Getty Scientists have identified a set of genetic variants that could help to explain why responses to obesity drugs vary markedly from person to person 1 .
- Co-author Adam Auton, vice-president of human genetics at 23andMe Research Institute, a non-profit organization in Palo Alto, California, that offers a DNA-testing service of the same name, acknowledges that the association was modest. “There’s a number of factors that can influence weight loss, of which genetics is a subcomponent.” But he notes that the genetic association with side effects was more substantial.
- Wide variation Next-generation weight-loss drugs mimic natural hormones that influence appetite and metabolism.

### Expert Commentary
This article covers drugs, obesity, weight topics. Areas of concern are also raised. Readability: Flesch-Kincaid grade 0.0. Word count: 851.