GLP-1 Drugs in Adolescents: What the Pediatric Obesity Evidence Actually Shows

GLP-1 receptor agonists moved into adult obesity care first, but two of them now carry U.S. pediatric indications, and the trials behind those approvals are worth reading closely. This is a research log entry, not clinical guidance: the goal here is to lay out what the published evidence says about semaglutide and liraglutide in adolescents, and where the open questions still sit.

Two FDA approvals for ages 12 and up

Liraglutide (Saxenda) was first. The FDA approved it on December 4, 2020, for adolescents aged 12 to 17 with a body weight above 60 kg and a BMI corresponding to 30 kg/m2 or greater in adults, as an adjunct to reduced-calorie eating and increased physical activity. At the time it was described as the first FDA-approved obesity therapy for adolescents in more than a decade.

Semaglutide (Wegovy) followed on December 23, 2022, for adolescents aged 12 and older with an initial BMI at or above the 95th percentile for age and sex on CDC growth charts, again alongside a reduced-calorie plan and more physical activity. Both are prescription drugs with pediatric labeling; you can cross-check current regulatory status on our FDA status reference page, since labels and indications change over time.

The semaglutide evidence: STEP TEENS

The pediatric semaglutide approval rests largely on STEP TEENS, a double-blind, randomized, placebo-controlled trial published in the New England Journal of Medicine in 2022. It enrolled adolescents aged 12 to under 18 with obesity (or overweight plus at least one weight-related condition), randomized 2:1 to once-weekly subcutaneous semaglutide 2.4 mg or placebo for 68 weeks, with lifestyle intervention for both groups.

The headline result was large. Mean BMI changed by -16.1% with semaglutide versus +0.6% with placebo, an estimated difference of roughly -16.7 percentage points. At week 68, 73% of the semaglutide group had lost 5% or more of body weight, compared with 18% on placebo, and improvements were also seen in waist circumference, HbA1c, and lipid measures.

Safety followed the pattern seen in adults. Gastrointestinal events (nausea, vomiting, diarrhea) occurred in 62% of semaglutide participants versus 42% on placebo, concentrated during dose escalation and mostly mild to moderate. Five semaglutide participants (about 4%) had gallbladder disease (cholelithiasis), with none in the placebo group. Serious adverse events were reported in 11% of the semaglutide group and 9% of placebo, and discontinuation rates for adverse events were similar between arms. No pancreatitis cases were reported.

The liraglutide evidence: SCALE Teens

Liraglutide's pediatric approval traces to a phase 3a trial (often called SCALE Teens) published in NEJM in 2020, run as a post-marketing requirement under the Pediatric Research Equity Act. It randomized 251 adolescents aged 12 to under 18 with obesity to liraglutide 3.0 mg (or maximum tolerated dose) or placebo, after a 12-week lifestyle run-in, across a 56-week treatment period plus follow-up.

The effect was more modest than the later semaglutide numbers. Liraglutide beat placebo on change in BMI standard-deviation score at week 56 (estimated difference -0.22). A BMI reduction of at least 5% occurred in about 43% of the liraglutide group versus 19% on placebo, and at least 10% in roughly 26% versus 8%. Gastrointestinal adverse events were again common, affecting 65% on liraglutide versus 37% on placebo. Notably, some of the weight benefit attenuated after treatment stopped during the follow-up period, a reminder that these are chronic-disease medications rather than short courses.

Where AAP guidance fits

These approvals landed alongside the American Academy of Pediatrics' 2023 Clinical Practice Guideline for the evaluation and treatment of children and adolescents with obesity. That guideline frames intensive health behavior and lifestyle treatment as the foundation of care, and says clinicians should offer weight-loss pharmacotherapy, including GLP-1 receptor agonists, to adolescents aged 12 and older as an adjunct, according to each medication's indications, risks, and benefits. It is a shared-decision framework, not a mandate to medicate. Prescribing did shift after the guideline: CDC and pharmacy data describe a several-hundred-percent rise in GLP-1 dispensing to adolescents aged 12 to 17 between 2020 and 2023.

Safety and growth considerations still under study

A few things make the pediatric picture genuinely different from adult use. Adolescents are still growing, so BMI is interpreted against age- and sex-specific percentiles rather than a fixed adult cutoff, and clinical monitoring accounts for ongoing development. The trials above ran to 56 to 68 weeks; long-term data on growth, bone, mental health, and what happens over years of treatment or after stopping remain comparatively thin. The recurrence of weight after liraglutide withdrawal underscores that these are not one-time interventions.

The bottom line from the evidence is narrow and specific: two GLP-1 drugs have randomized pediatric trials and FDA labeling for ages 12 and up, with meaningful average BMI reductions and a mostly gastrointestinal side-effect profile. Whether any of it applies to a given adolescent is a clinically supervised decision that weighs indication, comorbidities, growth, and family goals with a licensed pediatric clinician.

PepStash is a research log and reference tool. This article is educational and is not medical advice — it does not diagnose, treat, or recommend any protocol. Regulatory status and trial data change; always verify against primary sources and consult a licensed physician before making any decisions about your health.