GLP-1 Medications for Adolescents: What the Research Shows

Introduction

Roughly one in five adolescents in the United States now lives with obesity, and the trajectory rarely corrects itself with age — most adolescents with obesity become adults with obesity, often carrying cardiometabolic disease forward with them. Against that backdrop, the FDA approval of semaglutide (Wegovy) for adolescents 12 and older in December 2022 marked a significant shift in how pediatric obesity is treated, putting a once-weekly injectable medication into the same therapeutic conversation as diet, exercise, and bariatric surgery.

That shift has unsettled many parents. The drugs are powerful, the long-term data in young people is still maturing, and the cultural debate over treating adolescents with chronic medication is loud. The scientific picture, however, is increasingly defined by hard trial data rather than speculation.

Evidence: "Among adolescents with obesity, once-weekly subcutaneous semaglutide plus lifestyle intervention resulted in a greater reduction in BMI than lifestyle intervention alone, with a mean change in BMI of −16.1% versus +0.6% at week 68." — Weghuber D, et al. New England Journal of Medicine. 2022;387(24):2245–2257. DOI: 10.1056/NEJMoa2208601

The 2023 American Academy of Pediatrics clinical practice guideline pushed the field further, explicitly recommending that clinicians offer obesity pharmacotherapy to adolescents 12 and older as an adjunct to lifestyle treatment. Understanding what the trials actually demonstrated, which medications are approved, and where uncertainty remains is essential for any family considering this path.

Which GLP-1 Medications Are Approved for Adolescents

Three GLP-1 receptor agonists currently have pediatric or adolescent approvals in the United States, with distinct indications and age cutoffs.

Medication	Brand	FDA Pediatric Approval	Age	Indication
Liraglutide	Saxenda	December 2020	12+	Chronic weight management with BMI ≥ 95th percentile
Liraglutide	Victoza	June 2019	10+	Type 2 diabetes
Semaglutide	Wegovy	December 2022	12+	Chronic weight management with BMI ≥ 95th percentile
Semaglutide	Ozempic	Not approved	—	Type 2 diabetes (adults only)
Tirzepatide	Zepbound	Not approved	—	Adults only; pediatric trials underway

Wegovy is the only once-weekly GLP-1 medication currently approved for adolescent obesity. Saxenda (liraglutide) requires a daily injection. Tirzepatide — the dual GIP/GLP-1 receptor agonist marketed as Zepbound for obesity — remains adult-only in the U.S., though its pediatric program is now active.

Eligibility under both Saxenda and Wegovy labeling requires a body mass index at or above the 95th percentile for age and sex (the clinical threshold for obesity in adolescents), not merely overweight status. The drugs are not approved for cosmetic weight loss, and prescribing guidelines emphasize they should be combined with structured lifestyle intervention rather than used in isolation.

STEP TEENS: The Pivotal Semaglutide Trial

The FDA's 2022 decision to approve Wegovy in adolescents rested largely on STEP TEENS, a phase 3 randomized controlled trial published in the New England Journal of Medicine. The trial enrolled 201 adolescents aged 12 to under 18 with obesity (BMI ≥ 95th percentile) or overweight (BMI ≥ 85th percentile) with at least one weight-related comorbidity. Participants were randomized 2:1 to once-weekly semaglutide 2.4 mg or placebo, both alongside lifestyle counseling, for 68 weeks.

The magnitude of effect surprised even researchers who had run the adult STEP trials.

Evidence: "At week 68, 73% of participants in the semaglutide group had achieved at least 5% weight loss, compared with 18% in the placebo group. 45% of the semaglutide group achieved at least 20% weight loss, compared with 1% in the placebo group." — Weghuber D, et al. New England Journal of Medicine. 2022;387(24):2245–2257. DOI: 10.1056/NEJMoa2208601

Adolescents on semaglutide lost an average of 16.1% of body weight in 68 weeks — a result that exceeded the 14.9% mean weight reduction seen in the adult STEP 1 trial of the same drug at the same dose. The placebo arm gained a small amount of weight over the same period, consistent with the natural growth trajectory of adolescents with obesity.

Cardiometabolic Effects

Beyond weight, the trial documented improvements in waist circumference, hemoglobin A1c, lipid levels, and alanine aminotransferase. Blood pressure declined modestly. The proportion of participants meeting criteria for metabolic syndrome dropped meaningfully in the semaglutide arm.

Safety Profile in Adolescents

Gastrointestinal adverse events — nausea, vomiting, diarrhea — were the dominant side effects, matching the adult experience. Most were mild to moderate and concentrated during dose escalation. Four participants on semaglutide developed cholelithiasis (gallstones), a known class effect linked to rapid weight loss. There were no cases of medullary thyroid cancer, pancreatitis, or serious mental health events attributable to the drug during the trial. For more on adverse effects across this drug class, see our deep dive on GLP-1 side effects.

Liraglutide in Adolescents: The Earlier Data

Liraglutide's adolescent approval came two years before semaglutide's, based on a smaller phase 3 trial of 251 adolescents conducted across multiple international sites. The trial design mirrored STEP TEENS in important ways, but the effect size was substantially smaller — consistent with what is seen comparing the two drugs in adults.

Evidence: "Among adolescents with obesity, the use of liraglutide (3.0 mg) plus lifestyle therapy led to a significantly greater reduction in the BMI standard-deviation score than placebo plus lifestyle therapy at 56 weeks, with a mean difference in BMI SDS of −0.22." — Kelly AS, et al. New England Journal of Medicine. 2020;382(22):2117–2128. DOI: 10.1056/NEJMoa1916038

In absolute terms, liraglutide produced about 4–5% greater weight reduction than placebo at one year — meaningful, but a third of what semaglutide later achieved in the same population. Daily injections also create an adherence challenge that the once-weekly cadence of semaglutide largely sidesteps. For most clinicians and families, Wegovy has become the preferred GLP-1 option when one is appropriate.

The 2023 AAP Clinical Practice Guideline

In January 2023, the American Academy of Pediatrics issued its first comprehensive clinical practice guideline on adolescent obesity in 15 years. The document was significant for what it did not say as much as for what it did — it abandoned the long-standing "watchful waiting" approach in favor of early, intensive treatment.

Evidence: "Pediatricians and other PHCPs should offer adolescents 12 years and older with obesity (BMI ≥ 95th percentile) weight loss pharmacotherapy, according to medication indications, risks, and benefits, as an adjunct to health behavior and lifestyle treatment." — Hampl SE, et al. Pediatrics. 2023;151(2):e2022060640. DOI: 10.1542/peds.2022-060640

The guideline graded this recommendation as moderate-to-strong, citing accumulated RCT evidence for liraglutide, phentermine/topiramate, and at the time, emerging semaglutide data. It also recommended bariatric surgery evaluation for adolescents 13 and older with severe obesity. The recommendations were not without controversy — critics raised concerns about long-term safety data, equitable access, and the risk of medicalizing adolescence — but they reflected a broad shift in how the pediatric specialty views early intervention.

What Remains Uncertain

Several open questions sit between the current evidence base and routine clinical practice.

Long-Term Outcomes

STEP TEENS ran for 68 weeks. Liraglutide's pediatric trial ran for 56 weeks. Neither tells us what happens at five or ten years — whether weight loss is durable on continued therapy, what happens with discontinuation, or whether sustained GLP-1 receptor activation during adolescence has effects on growth, puberty, or long-term bone density that shorter trials cannot detect. Extension and registry studies are underway, but the foundational long-term data does not yet exist.

Discontinuation and Weight Regain

Adults who stop semaglutide typically regain two-thirds of lost weight within a year — the weight regain phenomenon is well documented. Whether adolescents follow the same pattern, and whether intermittent or maintenance dosing strategies might preserve gains, is an active research question with limited published data.

Mental Health Surveillance

Adolescence is the peak age window for emergence of mood disorders, eating disorders, and suicidality. Although GLP-1 trials have not demonstrated a causal mental health signal, the FDA and EMA continue to require post-marketing surveillance. Clinical guidelines recommend baseline and ongoing assessment for depression, anxiety, and disordered eating in adolescents on these medications.

Effects on Growth and Development

Adolescents are not small adults — they are actively growing and developing. Trial data suggest growth velocity is preserved on semaglutide and liraglutide, but the surveillance window remains short relative to a 5-to-7 year pubertal window. Bone health, in particular, warrants attention given the rapid weight loss and the known effects of caloric restriction on adolescent bone accrual.

The SURMOUNT-Adolescents Trial: Tirzepatide on the Horizon

Eli Lilly's tirzepatide is currently in phase 3 trials in adolescents under the SURMOUNT-Adolescents program. The trial enrolls participants aged 12 to under 18 with obesity, randomizing them to tirzepatide or placebo with lifestyle intervention. If the adult-to-adolescent translation seen with semaglutide holds, tirzepatide's roughly 20–22% adult weight reduction at the highest dose could produce even larger effects in adolescents than STEP TEENS demonstrated for semaglutide.

Readout is expected in the latter half of the decade. Until then, tirzepatide remains adult-only, and off-label prescribing in adolescents is not supported by current evidence or guidelines.

Practical Considerations for Families

For families weighing GLP-1 therapy for an adolescent, several practical factors matter alongside the trial data.

Insurance and cost. Wegovy and Saxenda are expensive, and adolescent coverage remains inconsistent. Many commercial plans require prior authorization documenting failure of lifestyle interventions, comorbidity presence, or BMI thresholds beyond the labeled criteria. Medicaid coverage varies by state.

Specialty care. AAP guidelines emphasize that pharmacotherapy works best within a multidisciplinary obesity treatment program — registered dietitians, behavioral health support, and a pediatrician or endocrinologist familiar with the medications. Standalone prescribing without behavioral support has worse outcomes.

Injection logistics. Once-weekly semaglutide is generally manageable for adolescents and parents, but the technique requires practice and the medications require cold-chain storage. See our guide on injection techniques for GLP-1 medications for a fuller walkthrough.

Family alignment. Adolescent obesity treatment is most successful when household food environment, activity patterns, and treatment goals are aligned across family members rather than placed solely on the adolescent.

Key Takeaways

The evidence for GLP-1 medications in adolescents 12 and older — particularly semaglutide — is now substantial enough that major pediatric specialty bodies recommend their use as an adjunct to lifestyle intervention for those with obesity. STEP TEENS demonstrated weight loss of 16% on average, with broad cardiometabolic improvements and a side-effect profile similar to that seen in adults. The 2023 AAP guideline formalizes this position in clinical practice.

Long-term data remains the most significant gap. Five-to-ten-year outcomes, growth and pubertal effects, mental health surveillance, and the consequences of discontinuation or intermittent use are all areas where current evidence is limited. For families and clinicians, the practical question is rarely whether the drugs work — STEP TEENS settled that — but how they fit into a broader treatment plan tailored to a specific adolescent's biology, comorbidities, and circumstances.

References

Weghuber D, Barrett T, Barrientos-Pérez M, et al. Once-Weekly Semaglutide in Adolescents with Obesity. New England Journal of Medicine. 2022;387(24):2245–2257. DOI: 10.1056/NEJMoa2208601
Kelly AS, Auerbach P, Barrientos-Perez M, et al. A Randomized, Controlled Trial of Liraglutide for Adolescents with Obesity. New England Journal of Medicine. 2020;382(22):2117–2128. DOI: 10.1056/NEJMoa1916038
Hampl SE, Hassink SG, Skinner AC, et al. Clinical Practice Guideline for the Evaluation and Treatment of Children and Adolescents With Obesity. Pediatrics. 2023;151(2):e2022060640. DOI: 10.1542/peds.2022-060640
U.S. Food and Drug Administration. FDA Approves Treatment of Chronic Weight Management in Pediatric Patients Aged 12 Years and Older. FDA News Release. December 23, 2022. FDA
Skinner AC, Ravanbakht SN, Skelton JA, et al. Prevalence of Obesity and Severe Obesity in US Children, 1999–2016. Pediatrics. 2018;141(3):e20173459. DOI: 10.1542/peds.2017-3459
Kelly AS, Fox CK, Rudser KD, Gross AC, Ryder JR. Pediatric obesity pharmacotherapy: current state of the field, review of the literature and clinical trial considerations. International Journal of Obesity. 2016;40(7):1043–1050. DOI: 10.1038/ijo.2016.69
Twig G, Yaniv G, Levine H, et al. Body-Mass Index in 2.3 Million Adolescents and Cardiovascular Death in Adulthood. New England Journal of Medicine. 2016;374(25):2430–2440. DOI: 10.1056/NEJMoa1503840

Last updated: 2026-05-11 Medical review: Dr. James Chen, MD, PhD, FACE