GLP-1 Drugs for Teens: The Evidence So Far

GLP-1 Special Populations

-16.1% BMI reduction

In the STEP TEENS trial, adolescents receiving semaglutide 2.4 mg weekly had a mean 16.1% BMI reduction at 68 weeks versus a 0.6% increase with placebo.

Weghuber et al., NEJM, 2022

Weghuber et al., NEJM, 2022

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The FDA approved semaglutide (Wegovy) for adolescents aged 12 and older with obesity in December 2022, based on a single Phase 3 trial of 201 participants lasting 68 weeks. Liraglutide (Saxenda) received pediatric approval earlier, in 2020, for ages 12 and up. In 2025, liraglutide was further approved for children ages 6 to 11. These approvals placed GLP-1 receptor agonists at the center of pediatric obesity treatment, a field where pharmacological options had been nearly nonexistent. Prescribing rates among adolescents rose 1.5-fold between 2023 and 2024.^[6] The efficacy data are striking: 73% of teens on semaglutide lost at least 5% of their body weight in the pivotal trial, compared to 18% on placebo. But the evidence base for adolescent use remains thin compared to adult data. There is one large randomized trial for semaglutide in teens. Long-term safety data beyond 68 weeks do not exist for this population. Questions about effects on bone density, linear growth, lean muscle mass, and psychological health during a critical developmental period remain open. This article examines every major study on GLP-1 drugs in adolescents: the trials that led to approval, the emerging safety signals, the weight regain data, and the gaps that remain. For related topics, see GLP-1 Agonists After Bariatric Surgery for weight regain patterns, GLP-1 Agonists in Older Adults for the opposite end of the age spectrum, GLP-1 Drugs and Pregnancy for fertility considerations, Who Qualifies for GLP-1 Weight Loss Drugs for eligibility criteria, and Do GLP-1 Drugs Work Differently Across Racial and Ethnic Groups for population-specific responses. For broader GLP-1 context, see Cost-Effectiveness of GLP-1s and Body Image After GLP-1 Weight Loss.

The STEP TEENS trial: the foundation of adolescent semaglutide approval

The entire FDA approval of semaglutide for adolescents rests on a single trial. STEP TEENS (NCT04102189), published in the New England Journal of Medicine in November 2022, enrolled 201 adolescents ages 12 to 17 with obesity (BMI at the 95th percentile or higher) or overweight with at least one weight-related comorbidity. Participants were randomized 2:1 to receive once-weekly subcutaneous semaglutide 2.4 mg or placebo for 68 weeks, with all participants receiving lifestyle intervention.^[1]

The primary endpoint was percentage change in BMI from baseline to week 68. The semaglutide group achieved a mean BMI reduction of 16.1%, while the placebo group had a mean BMI increase of 0.6%. The difference was statistically and clinically significant. At week 68, 73% of the semaglutide group had lost at least 5% of their body weight (vs. 18% on placebo), 62% had lost at least 10% (vs. 8%), and 37% had lost at least 20% (vs. 3%).^[1]

Cardiometabolic markers improved alongside weight loss. A secondary analysis by Arslanian et al. (2025) specifically examined insulin sensitivity and metabolic risk factors in the STEP TEENS population. Insulin resistance, measured by HOMA-IR, decreased by 2.90 in the semaglutide group while increasing by 0.71 with placebo. Triglycerides, LDL cholesterol, VLDL cholesterol, and alanine aminotransferase (ALT) all improved. Waist circumference decreased, and glycated hemoglobin levels fell.^[1]

The trial's limitations are worth noting. The 68-week duration, while adequate for demonstrating efficacy, does not address long-term safety or durability of effect in a population that may use these drugs for years or decades. The trial did not assess bone mineral density, linear growth velocity, or lean body mass composition in detail. In adult trials, approximately 39% of semaglutide-induced weight loss consists of lean mass (muscle and bone), a ratio that has particular implications for adolescents whose musculoskeletal systems are still developing.

Five patients in the semaglutide group developed cholelithiasis (gallstones), including one case of cholecystitis, compared to zero in the placebo group. Gastrointestinal adverse events (nausea, vomiting, diarrhea) were more common with semaglutide but generally mild to moderate.

Liraglutide in adolescents and younger children

Liraglutide (Saxenda) was the first GLP-1 receptor agonist approved for adolescent obesity, receiving FDA approval in 2020 for ages 12 and older. In 2025, the approval was extended to children ages 6 to 11 based on a randomized trial by Fox et al. that demonstrated BMI reduction in this younger age group.^[9]

Dong et al. (2025) conducted a meta-analysis of 7 randomized controlled trials evaluating long-term liraglutide administration for weight management in pediatric patients under 18. The pooled analysis found that liraglutide reduced BMI z-score by 0.30 compared to placebo, with consistent effects across studies. The safety profile was dominated by gastrointestinal events. No study in the meta-analysis exceeded 56 weeks of follow-up, and the authors emphasized the absence of data on musculoskeletal development, pubertal progression, and metabolic outcomes beyond one year.^[2]

Liraglutide requires daily injection, compared to semaglutide's weekly dosing. This difference affects adherence, particularly in adolescents. Real-world data from Noordam et al. (2025), the first longitudinal single-center analysis of liraglutide use in adolescents outside clinical trial conditions, reported outcomes in a Dutch cohort. At 12 months, BMI-SDS decreased by a mean of 0.24. Nausea occurred in 47% of patients. Twenty percent discontinued treatment, primarily due to gastrointestinal side effects or lack of perceived benefit.^[4]

Yaron et al. (2025) examined adherence patterns specifically, finding that treatment persistence with liraglutide in adolescents was lower than in clinical trials, with injection fatigue and side effects as the primary drivers of discontinuation.^[4]

The systematic evidence: what 22 studies show collectively

Kotecha et al. (2025) published the largest systematic review and meta-analysis of GLP-1 receptor agonists in children and adolescents in JAMA Pediatrics, encompassing 22 studies. The pooled data showed that GLP-1 RAs reduced BMI by a mean of 3.19 kg/m² compared to placebo or standard care. Effects were consistent across semaglutide, liraglutide, and exenatide, though semaglutide showed the largest individual effect size.^[3]

The safety analysis found that gastrointestinal events were the most common adverse effects across all GLP-1 RAs. Serious adverse events were rare but included cholelithiasis and pancreatitis. The review's most important conclusion was methodological: the authors identified "a paucity of long-term safety data" as the primary gap in the evidence base. Most studies lasted 6 to 12 months. None provided data beyond 68 weeks. In a population that might use these drugs throughout adolescence and into adulthood, this represents a substantial evidence gap.^[3]

Perez et al. (2025) reviewed GLP-1 receptor agonists and GIP/GLP-1 co-agonists (tirzepatide) in the treatment of obesity across special populations, including adolescents. The review noted that while short-term efficacy data are promising, adolescents and elderly patients represent populations where the risk-benefit calculus differs from middle-aged adults. For adolescents, the unique considerations include ongoing linear growth, bone mineral accrual, pubertal hormone dynamics, and the psychological context of weight management during identity formation.^[5]

Wen et al. (2025) provided a focused review of GLP-1 receptor agonists in pediatric obesity, examining the regulatory pathway, mechanism of action as it applies to developing bodies, and the gap between clinical trial populations and the broader pediatric population likely to receive these drugs in practice. The review emphasized that clinical trials selected for specific BMI thresholds and comorbidities, while real-world prescribing patterns may include a wider range of patients.^[6]

Safety signals specific to adolescents

Cholelithiasis (gallstones)

Rapid weight loss increases gallstone risk regardless of the method. In STEP TEENS, 5 of 134 semaglutide-treated adolescents (3.7%) developed cholelithiasis, compared to zero of 67 placebo recipients. This rate is consistent with adult data, but the clinical significance in adolescents merits monitoring because gallstone disease is rare in this age group under normal circumstances.^[1]

Psychiatric effects

Kotecha et al. (2025) specifically examined the risk of suicidal ideation and behaviors, depression, and anxiety with GLP-1 receptor agonist use in children and adolescents. The analysis, published as a preprint, found no statistically significant increased risk of suicidal ideation or behaviors with GLP-1 RA use compared to placebo across available trials. Depression and anxiety rates were similar between treatment and control groups. The authors cautioned that the analysis was limited by small sample sizes, short follow-up periods, and the exclusion of patients with active psychiatric conditions from most trials.^[7]

One concerning case report illustrates the complexity. Liekens et al. (2025) described an adolescent girl whose atypical anorexia nervosa worsened after starting semaglutide. The patient had obesity and was prescribed semaglutide for weight management, but the drug's appetite-suppressing effects exacerbated an underlying eating disorder that had not been diagnosed prior to treatment. The case raised questions about screening protocols and whether GLP-1 receptor agonists might unmask or worsen disordered eating in vulnerable adolescents.^[8]

Lean body mass and bone

Adult semaglutide trials show that roughly 39% of weight lost is lean mass rather than fat. In adolescents, where muscle development and bone mineral accrual are active processes, this proportion has not been independently measured. The STEP TEENS trial did not include DEXA scans or other body composition assessments. This is one of the largest gaps in the adolescent evidence base.^[1]

Peak bone mass, the maximum bone density an individual will achieve in their lifetime, is accumulated primarily between ages 12 and 20. Caloric restriction during this window, regardless of the mechanism, could theoretically reduce peak bone mass and increase long-term osteoporosis risk. Whether GLP-1 receptor agonists affect this process through caloric reduction alone or also through direct effects on GLP-1 receptors in bone tissue has not been studied. The apperley et al. (2025) study of liraglutide in adolescents assessed body composition and found changes in cardiometabolic variables but did not report bone density outcomes.^[4]

Growth and puberty

No published study has specifically assessed the effect of GLP-1 receptor agonists on linear growth velocity or pubertal timing in adolescents. GLP-1 receptors are expressed in bone tissue, and the interaction between caloric restriction, GLP-1 signaling, and growth hormone axis function during puberty is unknown. The 68-week STEP TEENS trial duration is too short to detect effects on final adult height. Adolescents in the trial were still growing, and the BMI-based primary endpoint does not distinguish between weight loss that accompanies normal growth and weight loss that might suppress it.

Weight regain after stopping treatment

One of the most significant questions for adolescent GLP-1 use is what happens when treatment stops. Quarenghi et al. (2025) reviewed weight regain after discontinuation of liraglutide, semaglutide, and tirzepatide across randomized studies. The pooled data showed a mean weight regain of 5.63 kg (5.81% of body weight) after drug cessation. The regain typically begins within weeks of stopping treatment and continues for at least 12 months.^[10]

These data come exclusively from adult studies. No adolescent-specific discontinuation study has been published. The weight regain pattern raises a fundamental question about treatment duration: if adolescents must continue GLP-1 therapy indefinitely to maintain weight loss, the risk-benefit calculation shifts because the total drug exposure becomes years or decades rather than months.

The STEP TEENS trial included a 7-week follow-up period after treatment ended. During this brief window, weight began to increase in the semaglutide group, consistent with the adult pattern. But 7 weeks is insufficient to characterize the full trajectory of weight regain in adolescents.^[1]

Real-world evidence versus clinical trial data

Clinical trials select motivated patients, provide structured lifestyle interventions, and monitor adherence closely. Real-world prescribing conditions differ in every respect. The gap between trial efficacy and real-world effectiveness matters for all drugs, but it matters particularly for adolescent GLP-1 use because adherence challenges are amplified in this age group.

Noordam et al. (2025) provided the first longitudinal real-world data on liraglutide in adolescents. The BMI reduction (0.24 BMI-SDS at 12 months) was smaller than what clinical trials showed. The 20% discontinuation rate within the study period suggests that a substantial minority of adolescents will not sustain treatment long enough to achieve the weight loss seen in trials.^[4]

Daily injection (liraglutide) versus weekly injection (semaglutide) also affects real-world adherence. Adolescents may find a weekly injection more acceptable, but the comparative real-world adherence data between the two drugs in this age group have not been published. The gap between trial efficacy and real-world effectiveness is not unique to GLP-1 drugs, but it is amplified in adolescents by factors that clinical trials cannot fully replicate: peer pressure around eating habits, school schedules that complicate injection timing, and the normal developmental drive toward autonomy that can conflict with parental oversight of a medical regimen.

Ethical and access considerations

Ryan et al. (2026) examined the ethical dimensions of semaglutide use in children, noting several tensions. GLP-1 drugs address a genuine medical problem: severe adolescent obesity carries cardiovascular, metabolic, and psychosocial consequences that lifestyle intervention alone fails to reverse in most cases. The 2023 AAP guidelines recommend pharmacotherapy for adolescents aged 12 and older with obesity. The clinical need is real.^[6]

The tensions arise around informed consent (adolescents may not fully understand lifetime treatment implications), equity (GLP-1 drugs cost $1,000-1,300 per month without insurance, creating access disparities), and the pressure that rapid prescribing growth places on a still-immature evidence base. Prescriptions among adolescents aged 12-17 rose from 9.9 per 100,000 in 2023 to 14.8 per 100,000 in 2024, a pace that outstrips the generation of long-term safety data.

The access disparity is particularly relevant for adolescent populations. Obesity disproportionately affects children from lower-income families and certain racial/ethnic groups. If GLP-1 drugs become the standard of care for adolescent obesity but remain unaffordable without insurance coverage, the treatment could widen rather than narrow existing health disparities. For population-specific considerations, see Do GLP-1 Drugs Work Differently Across Racial and Ethnic Groups.

What the evidence supports and what remains unknown

Established by clinical trial data:

• Semaglutide 2.4 mg weekly produces clinically meaningful BMI reduction in adolescents ages 12-17 with obesity, with 73% achieving at least 5% weight loss over 68 weeks.
• Liraglutide produces more modest but consistent BMI reductions in adolescents and children as young as 6.
• Short-term (up to 68 weeks) safety profiles are similar to adult populations, dominated by gastrointestinal side effects.
• Cardiometabolic improvements (insulin sensitivity, lipids, liver enzymes) accompany weight loss.

Supported by limited evidence:

• Real-world effectiveness is lower than clinical trial efficacy, with higher discontinuation rates.
• Gastrointestinal side effects cause a meaningful minority of adolescents to stop treatment.
• No increased risk of suicidal ideation has been detected in available data, though studies excluded patients with active psychiatric conditions.

Not established:

• Effects on bone mineral density, linear growth, or final adult height.
• Effects on lean body mass composition during adolescent development.
• Effects on pubertal timing or reproductive hormone dynamics.
• Weight trajectory after discontinuation in adolescents specifically.
• Safety and efficacy beyond 68 weeks.
• Comparative effectiveness of semaglutide versus liraglutide in the adolescent population.
• Whether GLP-1 drugs unmask or worsen eating disorders in susceptible adolescents.
• Optimal duration of treatment and criteria for stopping.

The fundamental challenge is that the adolescent evidence base is being built in real time. Prescriptions are increasing faster than safety data can accumulate. The one large randomized trial (STEP TEENS) demonstrated clear short-term efficacy, but the questions that matter most for a developing body, effects on bone, muscle, growth, and psychological health over years, remain unanswered.

The Bottom Line

GLP-1 receptor agonists are FDA-approved for adolescent obesity based primarily on a single 68-week Phase 3 trial showing 16.1% BMI reduction with semaglutide. Short-term efficacy is clear and cardiometabolic benefits are documented. The critical gaps are long-term: no data exist beyond 68 weeks on effects on bone density, linear growth, lean mass, or psychological health in this developing population. Weight regain after discontinuation is well-documented in adults but unstudied in adolescents. Real-world adherence and effectiveness appear lower than clinical trial results.

Frequently Asked Questions

Is semaglutide FDA approved for teenagers?

Semaglutide (Wegovy) is FDA-approved for adolescents aged 12 and older with obesity, defined as BMI at the 95th percentile or higher. The approval was based on the STEP TEENS trial, which enrolled 201 participants and showed a 16.1% BMI reduction at 68 weeks. It was approved in December 2022.

How much weight do teens lose on Wegovy?

In the STEP TEENS trial, adolescents receiving semaglutide 2.4 mg weekly had a mean BMI reduction of 16.1% at 68 weeks. Seventy-three percent lost at least 5% of body weight, 62% lost at least 10%, and 37% lost at least 20%. Real-world results from liraglutide studies show smaller reductions, with BMI-SDS decreasing by 0.24 at 12 months.

What are the side effects of GLP-1 drugs in adolescents?

Gastrointestinal effects (nausea, vomiting, diarrhea) are the most common, affecting up to 47% of adolescents in real-world data. In the STEP TEENS trial, 3.7% of semaglutide-treated teens developed gallstones versus none on placebo. Twenty percent of adolescents discontinued liraglutide in one real-world cohort due to side effects or lack of perceived benefit.

Do teens gain weight back after stopping semaglutide?

No adolescent-specific discontinuation study has been published. Adult data show average weight regain of 5.63 kg after stopping GLP-1 drugs, beginning within weeks of discontinuation. The STEP TEENS trial included a 7-week post-treatment follow-up that showed weight beginning to increase, consistent with the adult pattern.

Can semaglutide affect a teenager's growth?

This question has not been answered by available research. No study has assessed the effect of GLP-1 receptor agonists on linear growth velocity, bone mineral density, or pubertal timing in adolescents. GLP-1 receptors are expressed in bone tissue, and the interaction between caloric restriction, GLP-1 signaling, and growth during puberty is unknown. The 68-week STEP TEENS trial is too short to detect effects on final adult height.

What age can children take GLP-1 drugs for weight loss?

Liraglutide (Saxenda) is FDA-approved for children as young as 6 years old with obesity, based on a 2025 approval. Semaglutide (Wegovy) is approved for ages 12 and older. These are the only GLP-1 receptor agonists with pediatric weight management approvals. Tirzepatide does not yet have a pediatric indication for obesity.