GLP-1 for Teens 12-17: The Pediatric Evidence

Two GLP-1 therapies are now FDA-approved for adolescents with obesity: Wegovy (semaglutide 2.4 mg) in December 2022 and Saxenda (liraglutide 3.0 mg) in December 2020. The pivotal adolescent trials — STEP TEENS (Weghuber 2022 NEJM^[1]) and SCALE TEENS (Kelly 2020 NEJM^[2]) — established efficacy and a safety profile broadly consistent with the adult experience. The American Academy of Pediatrics 2023 clinical practice guideline (Hampl 2023^[3]) endorses pharmacotherapy from age 12 with intensive health behavior and lifestyle treatment. Tirzepatide is still in phase 3 for adolescents (SURMOUNT-ADOLESCENTS-2, NCT06439277^[11]). This article walks through what the pediatric evidence actually shows, the AAP prescribing pathway, the safety signals, and the practical barriers to access in 2026.

The honest summary

• STEP TEENS is the headline trial. Weghuber 2022^[1] randomized 201 adolescents 12-17 with obesity (mean BMI 37) to semaglutide 2.4 mg weekly or placebo plus lifestyle intervention. At week 68, BMI dropped 16.1% on semaglutide vs +0.6% on placebo; 73% achieved ≥5% weight loss vs 18% on placebo.
• SCALE TEENS is the liraglutide precedent. Kelly 2020^[2] randomized 251 adolescents 12-17 to liraglutide 3.0 mg daily or placebo. At week 56, BMI standard deviation score dropped 0.22 on liraglutide vs +0.01 on placebo; 43% achieved ≥5% BMI reduction vs 19% on placebo. Effect size is real but substantially smaller than semaglutide.
• AAP 2023 endorses pharmacotherapy at 12+. The clinical practice guideline (Hampl 2023^[3], executive summary^[4]) recommends offering weight-loss pharmacotherapy to adolescents age ≥ 12 with obesity, alongside intensive health behavior and lifestyle treatment (IHBLT) of at least 26 contact hours over 3-12 months.
• Tirzepatide is not yet pediatric-approved. The phase 3 SURMOUNT-ADOLESCENTS-2 trial (NCT06439277^[11]) is enrolling adolescents 12-17 with obesity; Lilly has guided to a readout in late 2026 with a potential filing in 2027. Until then, Mounjaro and Zepbound use in 12-17 is off-label.
• Bariatric surgery remains appropriate for some. The Teen-LABS prospective cohort (Inge 2016^[6], Inge 2019^[7]) and the ASMBS pediatric guidelines (Pratt 2018^[5]) support metabolic and bariatric surgery in adolescents with severe obesity who meet criteria. AAP 2023^[3] recommends referral for surgical evaluation at age ≥ 13 with BMI ≥ 120% of the 95th percentile plus comorbidities, or BMI ≥ 140% of the 95th percentile alone.

STEP TEENS: what semaglutide actually did in 12-17 year-olds

STEP TEENS (Weghuber 2022 NEJM^[1]) was a 68-week double-blind randomized trial of once-weekly semaglutide 2.4 mg vs placebo in 201 adolescents 12-17 with obesity (BMI ≥ 95th percentile) or overweight with weight-related comorbidity. The dose escalation matched the adult Wegovy schedule — 0.25 mg weekly with monthly step-ups to 2.4 mg by week 17. Every participant received a structured lifestyle intervention.

At week 68, the semaglutide arm lost 16.1% of body weight from baseline vs +0.6% on placebo — a treatment difference of 16.7 percentage points. Mean BMI dropped from 37.0 to 31.0 on semaglutide. Secondary endpoints were consistent: 73% of semaglutide-treated adolescents achieved ≥ 5% weight loss vs 18% on placebo; 62% achieved ≥ 10% vs 8%; 45% achieved ≥ 15% vs 3%. Waist circumference, HbA1c, total cholesterol, and lipid panel all improved.

Safety: gastrointestinal events (nausea, vomiting, diarrhea) occurred in 62% of the semaglutide arm vs 42% on placebo, the same pattern as the adult STEP trials. Serious adverse events were uncommon (11% semaglutide vs 9% placebo) and not concentrated in any single organ system. Cholelithiasis occurred in 4% vs 0%. No increase in depression or suicidal ideation was observed on standardized questionnaires — an actively-collected safety endpoint because of the historical pediatric-pharmacotherapy concern.

SCALE TEENS: the liraglutide picture is smaller

SCALE TEENS (Kelly 2020 NEJM^[2]) randomized 251 adolescents 12-17 with obesity to liraglutide 3.0 mg daily or placebo for 56 weeks with a 26-week off-treatment follow-up. The primary endpoint was change in BMI standard deviation score (BMI SDS). At week 56, BMI SDS dropped 0.22 on liraglutide vs −0.01 on placebo — a treatment difference of 0.22 SDS units. In percent terms: liraglutide produced about 5% reduction in BMI vs about 0.2% increase on placebo. 43% of liraglutide-treated adolescents achieved ≥ 5% BMI reduction vs 19% on placebo.

Notably, when liraglutide was stopped at week 56, the weight regain over the next 26 weeks was substantial — the off-treatment BMI SDS rose back toward placebo by week 82. This is the same regain pattern seen in adult liraglutide and adult semaglutide discontinuation studies and frames adolescent GLP-1 therapy as a chronic intervention, not a course of treatment.

Adverse events were the same GI-dominant pattern as adults: nausea, vomiting, and diarrhea were the most common treatment-emergent events. No new pediatric-specific safety signals emerged. Growth velocity, sexual maturation (Tanner staging), and bone-age progression were tracked and showed no clinically significant differences vs placebo.

The AAP 2023 clinical practice guideline

The American Academy of Pediatrics published its first comprehensive obesity guideline in 2023 (Hampl 2023^[3]). The key prescribing-related recommendations:

• Pharmacotherapy at age 12 or older. The guideline recommends pediatricians offer weight-loss pharmacotherapy to adolescents 12 and older with obesity, alongside intensive health behavior and lifestyle treatment (IHBLT). This is a Grade B recommendation (moderate evidence, moderate net benefit).
• IHBLT is the foundation. IHBLT is defined as ≥ 26 contact hours over a 3-12 month period, delivered by a multidisciplinary team, addressing nutrition, physical activity, and behavior. Pharmacotherapy is layered on top of IHBLT, not a substitute for it.
• Severe obesity warrants surgical evaluation referral. Adolescents 13 and older with BMI ≥ 120% of the 95th percentile (~ class II severe obesity) plus a comorbidity, or BMI ≥ 140% of the 95th percentile alone (class III), should be referred for metabolic and bariatric surgery evaluation at a qualified center.
• No watchful waiting. The guideline explicitly recommends against a wait-and-see approach. Pediatric obesity persists into adulthood in the large majority of affected children, and earlier intervention is associated with better long-term outcomes.

The 2024 JAMA review by Kelly and colleagues^[8] operationalizes the guideline: the suggested clinical sequence is IHBLT for 3-6 months, addition of pharmacotherapy if BMI trajectory has not improved, and surgical referral for adolescents meeting the severe-obesity thresholds. Pharmacotherapy and surgery are not mutually exclusive — GLP-1 treatment can bridge to surgery or be combined post-surgically.

BMI thresholds in pediatric obesity

Pediatric obesity is defined by BMI percentile (because absolute BMI does not adjust for age and sex during growth). The standard cutoffs (Stierman 2021^[9]):

• Overweight: BMI ≥ 85th percentile and < 95th percentile for age and sex.
• Obesity: BMI ≥ 95th percentile.
• Class II severe obesity: BMI ≥ 120% of the 95th percentile, or absolute BMI ≥ 35 kg/m², whichever is lower.
• Class III severe obesity: BMI ≥ 140% of the 95th percentile, or absolute BMI ≥ 40 kg/m², whichever is lower.

NHANES data through 2018 (Stierman 2021^[9]) document about 19% of US children and adolescents in the obesity range and about 6% in severe obesity. Trends since the 1999-2006 baseline have been upward across all subgroups.

Magnitude: % body weight change at ~ week 68

Safety considerations specific to adolescents

The pediatric trials surfaced no new safety signals beyond the adult experience, but several categories warrant active monitoring (Kelly 2024 review^[8], Bensignor 2022^[10]):

• Growth velocity. STEP TEENS and SCALE TEENS both tracked height and bone-age progression. Neither trial showed a clinically significant impact on linear growth or pubertal staging. Standard practice is to plot height on growth curves at every visit during titration.
• Psychiatric. Depression and suicidal ideation are pre-specified safety endpoints in adolescent trials given the FDA boxed warning history for other weight-loss drugs (rimonabant, sibutramine). STEP TEENS and SCALE TEENS used PHQ-9 and Columbia Suicide Severity Rating Scale; neither showed an increased signal vs placebo. AAP guidance recommends baseline mental-health screening before pharmacotherapy.
• Hypoglycemia. Clinically rare in obesity-only pediatric populations; meaningful only for adolescents with concurrent type 2 diabetes on insulin or sulfonylureas (Bensignor 2022^[10]). Standard practice: hold any sulfonylurea, reduce or hold insulin if HbA1c trending below 7%.
• Bone density. Adolescent bone density data on GLP-1 therapy are limited; the theoretical concern is that rapid weight loss during peak bone-mass accrual could blunt accrual. Trials did not include DEXA endpoints. Practical approach: ensure vitamin D and calcium sufficiency (800-1000 mg calcium, 600-1000 IU vitamin D daily per AAP guidance), encourage weight-bearing exercise, and consider DEXA at baseline if family history of early-onset osteoporosis.
• Pancreatitis and gallbladder disease. Adolescent reports are very rare; the relative risk is similar to the small adult signal. Cholelithiasis was observed in 4% on STEP TEENS semaglutide. Clinical practice is to counsel families on right-upper-quadrant pain and evaluate promptly.
• Medullary thyroid carcinoma. The boxed warning that applies to adult GLP-1 therapy (contraindicated in MEN2 and personal/family history of MTC) applies equally to adolescents.

Bariatric surgery in adolescents: Teen-LABS

The Teen-LABS prospective cohort (Inge 2016^[6], Inge 2019^[7]) followed 242 adolescents who underwent sleeve gastrectomy or Roux-en-Y gastric bypass. At three years, mean body weight dropped 27% from baseline; 70% achieved remission of type 2 diabetes, 76% achieved remission of hypertension, and 66% achieved remission of dyslipidemia. The 5-year comparison vs adult outcomes (Inge 2019^[7]) showed comparable weight loss with a higher rate of remission of comorbidities — suggesting earlier intervention captures more metabolic benefit before disease is fully established.

The ASMBS pediatric guidelines (Pratt 2018^[5]) and the AAP 2023 guideline^[3] converge on the same eligibility thresholds: age ≥ 13 with severe obesity (BMI ≥ 120% of 95th percentile plus comorbidity, or ≥ 140% alone). Sleeve gastrectomy is the most common adolescent procedure. GLP-1 therapy and bariatric surgery are not mutually exclusive — pharmacotherapy can bridge to surgery for adolescents not yet meeting criteria, or be added post-surgically for inadequate response or weight regain.

The practical prescribing pathway

1. Confirm diagnosis. Plot BMI on age- and sex-specific CDC growth curves. Calculate percentile and severity class (obesity, severe class II, severe class III).
2. Comorbidity workup. Standard labs include lipid panel, ALT/AST, fasting glucose and HbA1c, TSH, 25-OH vitamin D. Screen for sleep apnea (snoring, witnessed apneas, daytime sleepiness), depression, and NAFLD.
3. Begin IHBLT. AAP recommends ≥ 26 contact hours over 3-12 months delivered by a multidisciplinary team (Hampl 2023^[3]). For families without local IHBLT access, telehealth programs and structured online curricula are acceptable substitutes.
4. Layer in pharmacotherapy at 3-6 months if BMI trajectory is flat or worsening. Wegovy is the first choice based on effect-size data (Weghuber 2022^[1]); Saxenda is the alternative for patients or insurers preferring a daily injection or longer-established pediatric safety record. Phentermine is FDA-approved age ≥ 16 short-term; topiramate is off-label.
5. Titrate slowly. Wegovy escalation is the same as adults — 0.25 mg weekly for 4 weeks, then 0.5 mg, 1.0 mg, 1.7 mg, 2.4 mg at 4-week intervals. Saxenda escalates 0.6 mg daily by 0.6 mg weekly to 3.0 mg. Counsel families on GI side effects and antiemetic options.
6. Monitor every 1-3 months during titration and every 3 months at maintenance: weight, BMI percentile, growth velocity, blood pressure, comorbidity-related labs, PHQ-9 or PHQ-A, and side-effect inventory.
7. Refer for surgical evaluation if adolescent meets ASMBS/AAP criteria and BMI trajectory remains in severe obesity range despite pharmacotherapy + IHBLT.

Access and cost barriers in 2026

The practical bottleneck in 2026 is access, not evidence. Wegovy retail cost is approximately $1,349 per month and Saxenda approximately $1,500 per month. Commercial insurance coverage for adolescent indications is improving but still variable; Medicaid coverage is patchwork — most states do not cover GLP-1 therapy for adolescent obesity as of 2026, though several have begun adding coverage. Pharmaceutical company patient-assistance programs and manufacturer cash-pay channels (e.g., NovoCare for Wegovy) partially fill the gap.

Specialist availability is also constrained: pediatric endocrinology, pediatric obesity medicine, and IHBLT programs are concentrated at academic medical centers (Cincinnati Children's, Lurie Children's, Boston Children's, Texas Children's, and similar). Telehealth pediatric obesity care is emerging but still limited in scope and state availability. Families in rural or under-served areas often have multi-month wait lists for pediatric obesity specialty care.

What is still unknown

Several questions remain open as of 2026:

• Tirzepatide efficacy in 12-17. SURMOUNT-ADOLESCENTS-2^[11] is the pending phase 3 trial. Based on adult tirzepatide vs semaglutide comparisons, the expected adolescent BMI reduction may exceed semaglutide's 16.1%, though the trial will generate the actual numbers.
• Long-term safety beyond 68 weeks. The adolescent pivotal trials have 56-68 week core periods. Real-world adolescent registries are now accumulating multi-year data but have not yet matured to the point of changing prescribing.
• Effects on bone-mass accrual. Adolescent DEXA endpoints were not pre-specified in STEP TEENS or SCALE TEENS. This remains the most prominent residual safety question.
• Discontinuation strategies. The SCALE TEENS off-treatment follow-up showed rapid regain. Whether maintenance at a lower dose or scheduled wash-out periods can preserve benefit without lifelong injection is an open research question.

Related research and tools

• STEP TEENS in detail — the full breakdown of the semaglutide adolescent trial
• Wegovy for teenagers: a parent guide — the practical patient and family perspective
• Saxenda (liraglutide) evidence — SCALE TEENS adult and adolescent context
• GLP-1 and bone density — relevant background for the adolescent bone-mass-accrual question
• GLP-1 muscle loss prevention — the protein and resistance-training protocol that applies to adolescents as well
• GLP-1 protein calculator — daily target by current weight, applicable to adolescents on weight-based dosing

Important disclaimer. This article is educational and does not constitute medical advice. Adolescent obesity care should be coordinated through a pediatrician, pediatric endocrinologist, or pediatric obesity-medicine specialist with access to multidisciplinary IHBLT resources. Pharmacotherapy decisions in adolescents require informed consent from the patient and parent or guardian, baseline mental-health screening, and active growth and pubertal-staging surveillance. PMIDs were verified live against the PubMed E-utilities API on 2026-05-28.

Last verified: 2026-05-28. Next review: every 6 months, or sooner if SURMOUNT-ADOLESCENTS-2 reports or the AAP updates the 2023 clinical practice guideline.