Obsessive-compulsive disorder (OCD) is a challenging psychiatric condition with limited treatment responses to standard therapies like selective serotonin reuptake inhibitors and cognitive-behavioral therapy. This letter to the Editor is intended to raise awareness within the scientific community about the potential use of N-acetylcysteine (NAC) as an alternative treatment, targeting the glutamatergic system dysfunctions and the inflammatory cytokines implicated in OCD. Preliminary studies suggest that NAC, at doses of 2,000-3,000 mg daily, can significantly alleviate OCD symptoms. Despite its promise and favourable safety profile, further research is imperative to establish optimal dosages and long-term efficacy. To date, the lack of suitable pharmaceutical forms with appropriate dosages hinders its empirical clinical application. In conclusion, NAC offers a potential adjunctive treatment for OCD, meriting more rigorous investigation.