We present a case of a 17-year-old male with recurrent hair twirling resulting in patchy alopecia, who improved dramatically on N-acetylcysteine (NAC). Trichotillomania is characterized by repetitive hair pulling, twisting, or twirling and can vary from a mild habit to an impulse-control disorder. Standard treatment for pediatric trichotillomania includes cognitive behavioral therapy or medical therapy with selective serotonin reuptake inhibitors. NAC is a more recently utilized, safe, and well-tolerated over-the-counter supplement with some evidence of benefit for habitual skin and hair disorders. For this patient, we recommended 600 mg twice daily, increasing to 1200 mg twice daily as tolerated. After 6 months, our patient reported decreased desire to twirl his hair and his hair had almost completely regrown. Pediatricians who see patients with trichotillomania or other habitual disorders can consider treating these patients with NAC given its potential benefits and favorable side effect profile.