A 19‑year‑old man with autism, ADHD, type 2 diabetes and severe early‑onset obesity saw big improvements after starting tirzepatide, a drug that activates two gut hormones. Even though he didn’t have a known genetic cause for his overeating, his weight, appetite and blood sugar got much better, showing tirzepatide could work for teens with hard‑to‑treat obesity and hyperphagia.

Early-onset severe obesity is rare and largely treatment-resistant to standard measures. Etiologies include syndromic disorders (Prader-Willi, Bardet-Biedl and Alström syndromes), monogenic defects of appetite-regulating pathways - most significantly melanocortin-4-receptor (MC4R) deficiency, but also leptin receptor (LEPR), pro-opiomelanocortin (POMC), and secondary hypothalamic injury, most commonly craniopharyngiomas. Most childhood obesity, however, is polygenic, arising from interactions of environmental and genetic factors. In many patients, no clear etiology is identified. Treatment remains challenging, particularly if hyperphagia and reduced satiety are predominant presenting features. We describe the case of a 19-year-old male with a history of autism spectrum disorder, attention-deficit hyperactivity disorder (ADHD), type 2 diabetes mellitus (T2DM) and morbid obesity, who showed a clinically significant response to tirzepatide therapy following failed conventional interventions. This case highlights the potential role of dual incretin therapy in adolescents with severe early-onset obesity and hyperphagia, even in the absence (based on present knowledge) of identifiable hypothalamic or genetic pathology.