Semaglutide Shows Promise for Adolescent Obesity: Unpacking STEP TEENS

Last Updated: June 2024

Approximately 22% of adolescents aged 12-19 years in the United States currently live with obesity, according to the Centers for Disease Control and Prevention's 2020 data, a figure that continues to climb. This prevalence is a public health crisis, driving increased risks for type 2 diabetes, cardiovascular disease, and psychological distress in a vulnerable population. For years, interventions for adolescent obesity were primarily limited to lifestyle modifications and, in severe cases, bariatric surgery. The landscape shifted significantly with the advent of GLP-1 receptor agonists, and in particular, the STEP TEENS trial brought semaglutide (marketed as Wegovy for weight management) into the spotlight as a powerful pharmacological tool for this age group.

The STEP TEENS Data: A Turning Point

The pivotal STEP TEENS trial, published in the New England Journal of Medicine in December 2022, provided robust evidence for once-weekly semaglutide in adolescents with obesity. This 68-week, double-blind, randomized, placebo-controlled trial enrolled 201 adolescents aged 12 to 17 years, each with a BMI at or above the 95th percentile for their age and sex. Participants were randomly assigned to receive either once-weekly subcutaneous semaglutide (up to 2.4 mg) or placebo, in addition to a lifestyle intervention program.

The results were striking. The primary endpoint, the percentage change in BMI from baseline to week 68, showed an average reduction of 16.1% in the semaglutide group compared to an increase of 0.6% in the placebo group. This represents a substantial and clinically meaningful difference. Beyond the average, individual response rates highlighted semaglutide's efficacy: a remarkable 76% of adolescents receiving semaglutide achieved a BMI reduction of 5% or more, a figure that stood in stark contrast to just 15% in the placebo group. Moreover, nearly half (43.3%) of the semaglutide group achieved a BMI reduction of 20% or more, a level of weight loss previously uncommon outside of bariatric surgery. The study’s authors summarized their findings directly: "In this 68-week trial, once-weekly subcutaneous semaglutide plus lifestyle intervention resulted in a greater reduction in BMI than lifestyle intervention alone in adolescents with obesity." ¹

Secondary endpoints further underscored the benefits. Adolescents on semaglutide experienced significant improvements in cardiometabolic risk factors, including waist circumference, blood pressure, lipid profiles, and HbA1c levels. These are critical markers, given the increased risk of metabolic syndrome and type 2 diabetes that often accompanies adolescent obesity.

Safety Profile and Growth Considerations

The safety profile of semaglutide in adolescents generally mirrored that observed in adults. The most common adverse events were gastrointestinal in nature, including nausea, vomiting, diarrhea, and constipation, usually mild to moderate in severity and transient. Discontinuations due to adverse events were higher in the semaglutide group (16.2%) than in the placebo group (2.0%), predominantly due to these GI issues. Other adverse events reported in the trial included cholelithiasis (gallstones), a known risk associated with rapid weight loss, which occurred in a small percentage of both groups.

A primary concern for any medication administered to growing bodies is its potential impact on development. The STEP TEENS trial meticulously monitored growth parameters, including height and bone age. Crucially, the study reported no clinically meaningful differences in growth or pubertal development between the semaglutide and placebo groups over the 68-week period. This finding provides a level of reassurance regarding immediate developmental effects. However, the long-term implications on bone density, ultimate height attainment, or other aspects of adolescent development beyond the study period remain subjects for ongoing research. The cautious approach from regulators and physicians is understandable, yet the immediate and profound health risks of unaddressed severe obesity in adolescence cannot be understated.

The landscape of GLP-1 agonists for adolescents isn't limited to semaglutide. Liraglutide, another GLP-1 receptor agonist, was also approved for adolescents aged 12 and older based on the SCALE TEENS trial. Comparing the reported efficacy of these agents provides a clearer picture for clinicians and families:

Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Consult with a qualified healthcare provider before starting any medication. Last updated: March 25, 2026.

Drug	Mechanism	Age Group	% Achieving ≥5% BMI Reduction (Trial Data)