A new pooled analysis of the STEP clinical trials suggests that semaglutide — the active ingredient in Wegovy and Ozempic — remains effective and generally safe for older adults with obesity.
The results show meaningful weight loss and improved health markers in people 65 and above, with outcomes similar to younger participants.
The research was led by Professor Luca Busetto of the University of Padova and included data from multiple STEP studies.
Older adults with obesity often have more complex health profiles, including multiple chronic conditions and increased frailty.
Because of this, researchers have had limited clarity on how GLP-1 medications like semaglutide perform in this age group.
To investigate, scientists pooled data from STEP 1, 3, 4, 5, 8 and 9 trials, focusing specifically on participants aged 65 and older without diabetes.
This allowed for a clearer look at weight loss effects in a more medically consistent group.
Participants were randomly assigned to receive either semaglutide 2.4 mg once weekly or a placebo, alongside lifestyle guidance.
Outcomes were tracked over 68 weeks and included body weight, waist measurements, BMI changes, and cardiometabolic health markers.
Significant Weight Loss Over 68 Weeks
The analysis included 358 participants aged 65 or older, with most between 65 and 74 years old.
By the end of the study period, those taking semaglutide experienced an average weight reduction of about 15.4%, compared with 5.1% in the placebo group.
Waist circumference also decreased more substantially in the treatment group.
A much larger proportion of semaglutide users achieved clinically significant weight loss milestones.
Around two-thirds lost at least 10% of their body weight, nearly half lost 15% or more, and more than a quarter achieved weight loss of 20% or greater.
By comparison, far fewer participants in the placebo group reached those thresholds.
Improvements in Metabolic and Cardiovascular Markers
Beyond weight loss, semaglutide was associated with improvements in several cardiometabolic risk factors, including blood pressure, cholesterol, blood fats and blood sugar control indicators.
More participants in the semaglutide group also moved into healthier BMI categories and achieved improved waist-to-height ratios, both of which are linked to lower long-term health risk.
Overall side effect rates were high in both groups, which is common in long clinical trials, but slightly higher among those taking semaglutide.
Serious adverse events were reported more often in the semaglutide group, though most commonly reported side effects included gastrointestinal symptoms like constipation, along with dizziness.
Rates of hypoglycemia and fractures remained low and similar between groups.
What the Findings Suggest
Researchers concluded that semaglutide’s effectiveness in older adults closely mirrors results seen in the wider STEP trial population, suggesting it performs consistently across age groups.
They also noted that obesity in adults over 65 is a major contributor to long-term health complications and reduced quality of life, making effective treatment options especially important in this population.
Overall, the findings support the use of semaglutide as a treatment option for obesity in older adults, with benefits that extend beyond weight loss alone to broader metabolic health improvements.
Lorra Garrick is a former personal trainer certified by the American Council on Exercise. At Bally Total Fitness, where she was also a group fitness instructor, she trained clients of all ages and abilities for fat loss and maintaining it, muscle and strength building, fitness, and improved cardiovascular and overall health.
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