GLP-1 drugs such as Ozempic, Wegovy and Mounjaro are already known for helping people lose weight, but a large new study suggests the benefits go well beyond the scale. Researchers report that patients who shed the most weight on these medicines faced substantially lower risks of several obesity-related diseases.
The work, led by scientists at the University of Liverpool in the UK, was presented at the European Congress on Obesity. It focuses on medications that mimic the hormone glucagon-like peptide-1, which reduces appetite, slows digestion and improves blood sugar control. Some newer drugs in this class also copy a second hormone called GIP.
How the study was designed
The team analysed electronic health records for 89 718 adults in the US who began taking a GLP-1 or dual GLP-1/GIP drug between January 2021 and June 2024. Participants were tracked for changes in body mass index over the first treatment year and then followed for an average of 11 further months.
Patients were grouped by how much weight they lost, from less than 5 percent of their BMI to at least a 15 percent reduction. The researchers then compared the later development of conditions closely linked with obesity, including osteoarthritis, chronic kidney disease, obstructive sleep apnea and heart failure.
Greater weight loss, lower disease risk
People whose BMI fell by 15 percent or more had markedly better outcomes than those who lost between 0 and 5 percent. In the highest weight-loss group, the risk of osteoarthritis was 37 percent lower and chronic kidney disease risk was cut by 30 percent, after adjusting for other factors.
The benefits were even more striking for certain conditions. The risk of developing obstructive sleep apnea fell by 69 percent in those with the largest BMI drops, while heart failure risk was reduced by 32 percent. For all outcomes except heart failure, the associations met conventional thresholds for statistical significance.
Not everyone responded to treatment. A subset of patients actually gained weight while using the drugs, and compared with the modest-weight-loss group, they faced a significantly higher risk of sleep apnea and heart failure during follow-up. This pattern underlined how closely disease risk tracked with weight change.
Adherence and long-term questions
About half of all participants stopped taking their GLP-1-based medication before the first year ended, reflecting real-world challenges with cost, side effects and access. Despite this, these individuals remained in the analysis, offering insight into outcomes outside tightly controlled clinical trials.
The findings add nuance to growing evidence that GLP-1 therapies may benefit the heart and kidneys. In this dataset, much of that protection appeared tied to how much weight patients actually lost, rather than a uniform drug effect regardless of body mass change.
The study comes as clinicians wrestle with concerns about long-term safety, mental health side effects and weight regain after stopping GLP-1 treatment. Other research has shown that many patients regain a large share of lost weight within a year of discontinuation, raising questions about how durable these health gains will be.
Implications for obesity treatment
The authors concluded that achieving and maintaining meaningful weight loss is critical if patients are to realise the full medical benefits of GLP-1 therapy. In their words, not losing weight after starting these drugs was linked with worse clinical outcomes, while larger reductions were associated with decreased risks.
Experts say the work reinforces the view of obesity as a chronic disease that often requires long-term, sometimes lifelong, treatment. The results are likely to feed into ongoing debates over insurance coverage, prescribing guidelines and how best to support patients in staying on therapy safely.
More detailed peer-reviewed publication of the data will be needed to clarify unanswered questions, including how results vary by age, sex and underlying health. For now, the study offers one of the clearest real-world signals that substantial weight loss on GLP-1 drugs can translate into lower risks of several serious conditions linked to obesity.
