This systematic review examined 42 studies on psychedelics for PTSD, including ketamine, MDMA, and psilocybin, out of more than 5,000 screened papers. MDMA showed the most consistent and durable symptom reductions when used in controlled, therapy-supported settings, while ketamine produced rapid improvements that often faded unless doses were repeated or paired with psychotherapy. Evidence for psilocybin and other psychedelics remains early and limited, but generally pointed toward potential benefit with mostly short-term, manageable side effects. Overall, the review supports cautious optimism while emphasizing that these approaches remain investigational and dependent on structured clinical care and integration.