MK-677 in Adolescents: Pediatric Trials Are Not Teen Safety Data
At a glance
- FDA approval / none for ibutamoren in any age group
- Published 2001 pediatric study / 18 prepubertal children with growth hormone deficiency; 7–8 days
- Completed Phase 2 registry / 104 enrolled; 82 entered randomized treatment
- Phase 2 population / treatment-naive, prepubertal children with idiopathic growth hormone deficiency
- Phase 2 age limits / girls 3–11; boys 3–12
- General adolescent or healthy-teen trial / not identified
- Adolescent dose or monitoring protocol / not established
- Medical review / current review of this revision is pending
The Correction: Pediatric Exposure Exists
The legacy page said no pediatric trial existed, then built a detailed teen risk and monitoring protocol from adult studies. Both moves were unsound.
Codner and colleagues described the purpose of their 2001 study this way:
“We evaluated the safety and tolerability and the GH-insulin-like growth factor (IGF) responses to two dosages of oral ibutamoren mesylate given to children”
The speakers are Ethel Codner, Fernando Cassorla, Alexander Tiulpakov, Verónica Mericq, and coauthors from pediatric endocrine and clinical research institutions. Their Clinical Pharmacology & Therapeutics study enrolled 18 prepubertal children with idiopathic growth hormone deficiency for only 7–8 days. The excerpt establishes pediatric exposure; it does not establish safety in adolescents, healthy children, or longer use.
The Age-and-Development Evidence Map
| Evidence source | Population | Exposure and follow-up | What it can answer | What it cannot answer |
|---|---|---|---|---|
| Codner et al., 2001 | 18 prepubertal children with idiopathic GHD; mean chronological age 10.6 years | Two weight-based study arms for 7–8 days | Short-term GH, IGF-1, IGFBP-3, and measured laboratory response | Pubertal safety, final height, long-term metabolic outcomes, or healthy-teen use |
| OraGrowtH210, NCT04614337 | Prepubertal girls ages 3–11 and boys ages 3–12 with selected idiopathic GHD | 104 enrolled; 82 randomized; up to 24 months; results posted June 2026 | Registered growth, PK, hormone, and adverse-event outcomes in that selected population | General ages 12–17, pubertal development, sports use, or an approved regimen |
| FDA 2024 compounding review | Cross-population literature and safety review | Regulatory evidence synthesis | Product characterization, effectiveness limits, and identified safety concerns | A teen-specific treatment protocol |
| FDA 2025 hidden-ingredient alert | A product marketed to children ages five and older | FDA laboratory identification and consumer warning | Risk of undisclosed ibutamoren exposure | Incidence or safety of a characterized prescribed product |
The crucial dividing line is not merely age 18. It is developmental stage, diagnosis, selection criteria, formulation, exposure duration, and outcome measured.
What the Completed Phase 2 Record Adds
NCT04614337 is no longer merely a planned trial. Its registry record was updated with results in June 2026. The study enrolled 104 children for a predictive-enrichment qualification phase; 82 entered randomized LUM-201 or recombinant growth hormone groups.
The record reports growth, weight, BMI, bone-age, pharmacokinetic, hormone, and adverse-event outcomes. But its eligibility criteria required prepubertal status and idiopathic growth hormone deficiency. Mean age among randomized participants was about eight years.
Those results deserve interpretation on their own terms. They cannot be converted into:
- a dose for a healthy 15-year-old;
- a bodybuilding or performance regimen;
- a conclusion about pubertal progression;
- a universal growth-height claim;
- a monitoring schedule for unsupervised products; or
- evidence that an online or compounded product matches the study formulation.
The Study Dose Is Not a Teen Dose
The pediatric studies used weight-based experimental arms under protocols with eligibility testing, controlled formulations, defined measurements, and investigator oversight. A study arm is part of an experiment. It is not a recommendation that survives a change in age, diagnosis, puberty, product, or purpose.
FDA's 2024 review concluded that available data were insufficient to support effectiveness for growth hormone deficiency and other nominated uses. The agency also identified potential concerns involving hyperglycemia, liver-enzyme elevation, edema and fluid overload, and growth-hormone/IGF-1-related effects. Those cross-population concerns are relevant context, but they do not prove a teen-specific incidence rate.
Product Identity Is a Separate Safety Variable
In September 2025, FDA reported finding undeclared ibutamoren in a product promoted for children. That alert shows why “MK-677” on a web page is not enough to define what a person actually received.
An adolescent decision would need at least four distinct answers:
- What condition is being studied or treated?
- Is the person prepubertal, pubertal, or postpubertal?
- What exact product and formulation is being administered?
- What outcome and time horizon does the evidence cover?
The young-adult dosing audit explains why experimental arms do not become regimens at age 18. The young-adult safety review maps the small adult evidence denominator, and the food and supplement evidence page separates formal interaction evidence from mechanism.
The Responsible Bottom Line
Ibutamoren has pediatric clinical data, including newly posted Phase 2 results. The evidence is nevertheless population-specific: selected, prepubertal children with diagnosed growth hormone deficiency. It does not establish a general adolescent indication, safety profile, dose, growth promise, puberty protocol, or performance use.
Medical review of this revision is pending. FDA, ClinicalTrials.gov, sponsors, investigators, institutions, and study authors do not endorse ibutamoren, HealthRX.com, or this page.
Frequently asked questions
Has MK-677 been studied in children?
Did the Phase 2 pediatric trial include teenagers?
Does the pediatric study establish a dose for a healthy teenager?
Is ibutamoren FDA-approved for pediatric growth hormone deficiency?
References
- Codner E; Cassorla F; Tiulpakov AN; Mericq MV; Avila A; Pescovitz OH; Svensson J; Cerchio K; Krupa D; Gertz BJ; Murphy G. Effects of oral administration of ibutamoren mesylate, a nonpeptide growth hormone secretagogue, on the growth hormone-insulin-like growth factor I axis in growth hormone-deficient children. Clinical pharmacology and therapeutics. 2001 Jul;70(1):91-8. DOI 10.1067/mcp.2001.116514. PMID 11452249. https://pubmed.ncbi.nlm.nih.gov/11452249/
- National Library of Medicine, ClinicalTrials.gov. Lumos Pharma. A Multicenter, 24-Month, Randomized, Open-Label, Active Control, Parallel Arm, Phase 2 Study of Daily Oral LUM-201 in Naïve-to-Treatment, Prepubertal Children With Idiopathic Growth Hormone Deficiency (GHD). NCT04614337. Phase 2; completed; actual enrollment 104; first posted November 4, 2020; last update and results posted June 17, 2026; accessed August 30, 2026. https://clinicaltrials.gov/study/NCT04614337
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research. Evaluation of Ibutamoren Mesylate for Inclusion on the 503A Bulk Drug Substances List. July 3, 2024; PCAC meeting October 29, 2024. See PDF pages 18–19, 41–50. https://www.fda.gov/media/182087/download
- U.S. Food and Drug Administration. Agebox iKids Growth Day Formula May Be Harmful Due to Hidden Ingredient. September 23, 2025. https://www.fda.gov/drugs/medication-health-fraud-notifications/agebox-ikids-growth-day-formula-may-be-harmful-due-hidden-ingredient