Trichotillomania is a chronic mental disorder characterized by recurrent hair-pulling. Hoarding, excoriation and trichotillomania are classified as obsessive-compulsive related disorders in DSM-5, which share similar clinical presentations, characterized by inappropriate and excessive repetitive behaviors and dysregulation of inhibitory control processes. Research evidence suggests that abnormalities in the cortico-striato-thalamic-cortical circuits are one of the key factors underlying the pathophysiology of obsessivecompulsive related disorders, including trichotillomania. Glutamate is the primary neurotransmitter within the cortico-striato-thalamiccortical circuits. Therefore, the use of glutamate-modulating agents is subject to interest for obsessive-compulsive related disorders. N-acetylcysteine, a derivate of the amino acid L-cysteine, has been explored as potential therapy for obsessive-compulsive related disorders, including trichotillomania. Pharmacotherapies that target the prefrontal glutamatergic system, such as N-acetylcysteine, may correct the underlying pathophysiologic abnormalities and symptoms of trichotillomania. Even a limited number of studies are suggesting that N-acetylcysteine is a promising treatment option, these studies did not assess treatment effects exceeding 3-4 months treatment period. Longer term effects of N-acetylcysteine therapy in trichotillomania require further evaluation.