Study Shows: Ozempic Leads to Significant Weight Loss in Adults Over 65

A new analysis of the STEP studies suggests that semaglutide, the active ingredient in the popular weight-loss and diabetes treatment drugs Wegovy and Ozempic, remains effective and generally safe in adults over 65 with obesity. The researchers found that older adults taking the once-weekly obesity medication experienced significant weight loss as well as improvements in several key health parameters, with results similar to those of the broader STEP study population. The study was led by Prof. Luca Busetto of the University of Padua in Italy, along with colleagues, including researchers from Novo Nordisk, the manufacturer of semaglutide and sponsor of the study.

How Ozempic Works

Ozempic was originally developed to treat type 2 diabetes. It helps lower blood sugar levels and can also reduce the risk of certain cardiovascular diseases in people with diabetes. Many patients also lose weight while on the therapy, which is why the drug has received significant attention. Wegovy contains the same active ingredient, but in a higher dosage and with explicit approval for the treatment of obesity or severe overweight. It is primarily used in adults with a significantly elevated body mass index or in those who are overweight with comorbidities such as high blood pressure, sleep apnea, or diabetes.

Both medications are typically injected under the skin once a week using a pre-filled pen, usually in the abdomen, thigh, or upper arm. Treatment begins with a low dose that is gradually increased so that the body can adjust to the active ingredient and side effects such as nausea, diarrhea, or bloating remain as minimal as possible. The therapy is usually combined with dietary changes, exercise, and medical supervision, as the medications alone cannot replace a lasting lifestyle change.

Semaglutide Studied in Older Adults

Older adults with obesity are often considered medically vulnerable, as they frequently suffer from multiple health problems and exhibit increased frailty, which can raise the risk of adverse events (AEs). According to researchers, there is currently limited information on how glucagon-like peptide-1 (GLP-1) receptor agonists such as semaglutide work in this age group. To better understand the drug’s effects, the researchers analyzed data from the STEP 1, 3, 4, 5, 8, and 9 studies.

The analysis included only individuals with obesity or overweight who did not have diabetes, as weight loss in studies of obesity medications is generally lower in people with diabetes, making direct comparisons difficult. Participants were ≥ 65 years old and had a body mass index of at least 30 kg/m² or at least 27 kg/m² with at least one obesity-related complication (excluding diabetes). They were randomly assigned to either the 2.4 mg semaglutide group or the placebo group. All participants also received a lifestyle intervention, while participants in the STEP-3 study additionally received intensive behavioral therapy. The researchers evaluated the results over a period of 68 weeks. These included changes in body weight, waist circumference, waist-to-height ratio (WHtR), BMI category, and cardiometabolic risk factors such as blood pressure, cholesterol, blood lipids, glucose levels, and hs-CRP. Adverse events (AEs) were also monitored.

Significant Weight Loss and Health Improvements

Of the total study population (N = 4,523), 358 participants were 65 years or older and were included in the analysis. Of these, 248 received semaglutide 2.4 mg and 110 received a placebo. Most participants (90%) were between 65 and 74 years old, while the rest were 75 years or older. At the start of the study, the average age of participants was 69 years. The average body weight was 99.0 kg, the average BMI was 36.6 kg/m², and the average waist circumference was 115 cm. Women accounted for 72% of the participants.

By week 68, participants treated with semaglutide had achieved an average weight loss of −15.4%, compared with −5.1% in the placebo group. Waist circumference also decreased more significantly with semaglutide, reducing by an average of −14.3 cm compared with −6.0 cm with placebo. The proportion of participants who achieved key weight loss milestones was also significantly higher in the semaglutide group. A weight reduction of at least 10% was achieved by 66.5% of semaglutide participants, compared with 15.5% of placebo recipients. For weight loss of at least 15%, the figures were 46.8% versus 6.4%, while 28.6% of semaglutide users lost at least 20% of their body weight, compared to 2.7% in the placebo group.

Improvements in BMI and Cardiometabolic Health

The researchers also observed notable improvements in the waist-to-height ratio and BMI categories among semaglutide users. In the semaglutide group, 11.3% achieved a WHtR < 0.53, compared to 4.5% in the placebo group. Over the course of the study, more participants receiving semaglutide also moved into healthier BMI categories (see figure in the full abstract).

A BMI of <27 kg/m² (so-called normal weight) was achieved by 27.0% of participants taking semaglutide, compared with 5.5% of those receiving placebo. The proportion of participants classified as overweight or in obesity classes I, II, and III decreased in the semaglutide group as more individuals reached healthier weight ranges. Among participants who achieved both a BMI of 27 or less and a WHtR of <0.53, these figures were 10.5% and 2.7%, respectively. The semaglutide group also showed greater improvements in cardiometabolic risk factors, including blood pressure, cholesterol, blood lipids, and glycated hemoglobin (HbA1c—a measure of blood sugar control used in the diagnosis of diabetes).

Safety Results and Adverse Events

The overall incidence of adverse events (AEs) was similar in both groups, affecting 89.1% of semaglutide participants and 84.5% of placebo participants. However, serious adverse events were reported more frequently in the semaglutide group and occurred in 19.0% of participants, compared with 12.7% in the placebo group. Constipation and dizziness, known side effects of this class of medications, occurred more frequently with semaglutide. The incidence of bone fractures and hypoglycemia was similar in both groups and affected less than 1% of participants in each group.

Dr. Busetto summarizes: “In this analysis of individuals with obesity aged 65 years and older, semaglutide reduced body weight and improved cardiometabolic risk factors compared to placebo, and the safety and efficacy profile of semaglutide was consistent with that reported in the STEP program.” He adds: “In many countries, including numerous high-income countries, the majority of cases of overweight actually occur in adults aged 65 and older, representing a major driver of obesity-related complications and a significant cause of reduced quality of life and disability. Our results support the use of semaglutide in this patient group.”