Your Genes May Decide How Well Weight Loss Drugs Work: Study

Why do some people lose dramatic amounts of weight on GLP-1 drugs while others see only modest results? A new study published in journal Nature suggests the answer may partly lie in genetics. Researchers have found that certain gene variants may influence how effectively popular weight loss medications such as Wegovy and Ozempic work in different individuals. Scientists say the findings could help explain why responses to GLP-1 medications vary widely, including differences in weight loss and side effects such as nausea and vomiting. However, experts caution that genetics are only one part of a much larger picture involving age, sex, lifestyle, medical conditions, and treatment adherence.

What Did The Study Find?

Researchers analysed genetic and self-reported health data from nearly 28,000 people who had used GLP-1 medications for weight loss or diabetes management.

Also read: Beyond GLP-1: New 5-In-1 Compound More Effective Than Semaglutide For Diabetes And Weight Loss

The study identified a variant in the GLP1R gene, which produces the receptor targeted by GLP-1 drugs. People carrying this variant appeared to lose slightly more weight compared to those without it. Researchers estimated that individuals with two copies of the variant lost more than three pounds extra on average during treatment.

Scientists also identified another genetic variation linked to higher chances of nausea and vomiting, particularly in people taking tirzepatide-based medications.

Why Do GLP-1 Drugs Work Differently In Different People?

GLP-1 medications mimic hormones involved in appetite regulation and blood sugar control.

These drugs help:

• Reduce hunger
• Slow stomach emptying
• Increase feelings of fullness
• Improve glucose regulation

However, experts say not everyone responds equally. Some people lose substantial weight, while others experience minimal changes despite taking the same medication. Researchers believe genetic differences may partly affect:

• Appetite signalling
• Drug sensitivity
• Metabolism
• Side effect risk

Genetics Are Important, But Not The Only Factor

Scientists emphasise that genes alone do not determine treatment success. Other factors influencing weight loss outcomes include:

• Age
• Sex
• Existing diabetes
• Sleep and stress levels
• Physical activity
• Diet and nutrition
• Medication dosage and consistency

Experts say obesity itself is a complex condition influenced by both biology and environment.

Side Effects May Also Be Linked To Genes

The research suggested that some of the same gene variants associated with better weight loss were also linked to stronger gastrointestinal side effects such as nausea or vomiting. Doctors say common side effects of GLP-1 medications may include:

• Nausea
• Vomiting
• Diarrhoea
• Constipation
• Bloating

In some people, severe gastrointestinal symptoms may reduce appetite further, indirectly contributing to greater weight loss.

Could Genetic Testing Guide Future Obesity Treatment?

Researchers say the findings may eventually support more personalised obesity treatment approaches. In the future, doctors may potentially use genetic information to:

1. Predict who may respond best to certain drugs
2. Identify patients at higher risk of side effects
3. Personalise obesity medication strategies

However, experts say current evidence is still too limited for routine genetic testing before prescribing GLP-1 medications.

Also read: GLP-1 Drugs May Trigger Muscle Loss In Cirrhosis Patients: Study

Obesity Treatment Is Rapidly Evolving

GLP-1 medications have transformed obesity management globally over the past few years. Studies show these medications may also improve:

• Blood sugar control
• Heart health
• Inflammation
• Mobility and physical function

Researchers are continuing to explore why some patients respond better than others and how future treatments can become more personalised. A new study suggests genetic differences may partly explain why weight loss drugs like Wegovy and Zepbound work better for some people than others. While genes may influence both weight loss and side effects, experts say lifestyle, medical history, and overall health still play major roles in determining how well GLP-1 treatments work.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.