Johns Hopkins researchers found that GLP-1 drugs promote weight loss across a broad range of patients, with women losing more weight on average than men.
The medications may offer benefits beyond weight loss, but evidence varies depending on the condition and drug.
Side effects, muscle loss and difficulty maintaining treatment remain concerns, particularly for older or frail patients.
GLP-1 medications help a wide range of patients lose weight, according to a Johns Hopkins-led research review that found generally consistent effectiveness across age, race, ethnicity, starting body mass index and average blood sugar levels. Women, however, experienced greater weight loss than men.
The findings, highlighted in a fall Johns Hopkins Magazine article, come as researchers examine both the expanding benefits of these medications and the challenges patients face when taking them over time.
The review, published in JAMA Internal Medicine, included 41 articles representing 64 randomized clinical trials. In six trials involving nearly 20,000 patients analyzed by sex, women lost an average of 10.9% of their starting weight, compared with 6.8% among men.
The findings
Those figures reflect averages across the included trials, rather than a prediction of what an individual patient will lose. The researchers found no statistically significant differences in treatment effects across the other patient characteristics examined.
G. Caleb Alexander, a Johns Hopkins professor of epidemiology and medicine, told the magazine that an interaction with estrogen could help explain the difference between women and men, although that explanation remains unproven.
“These drugs are transformative—a real game changer,” Alexander said.
The magazine also describes research into possible benefits involving addiction, osteoarthritis and cancer risk. Those possibilities should be distinguished from established uses: promising associations do not necessarily demonstrate that a medication caused an improvement.
Some benefits beyond weight management already appear in prescribing information. Wegovy, for example, is approved to reduce major cardiovascular events in adults with established cardiovascular disease and overweight or obesity. Its injectable formulation also has accelerated approval for certain adults with a form of metabolic liver disease and moderate to advanced fibrosis. These indications apply to specific patient groups.
Issues for consumers
For consumers, tolerability too the drugs and continued access remain central issues. Alexander recommends smaller meals, hydration and gradual dose increases to help manage digestive symptoms. He also highlights muscle loss as a concern for older and frail patients.
The magazine reports that approximately 50% to 75% of patients discontinue treatment within the first year in cited studies. Side effects, cost and insurance coverage contribute, and weight regain is common after stopping.
Serious risks also require attention. Wegovy’s prescribing information warns about pancreatitis, gallbladder disease, kidney injury related to dehydration and low blood sugar, especially when combined with certain diabetes medicines. Its boxed thyroid-tumor warning stems from animal findings; whether it causes those tumors in humans remains unknown.