Post-traumatic stress disorder (PTSD) is a common mental health condition that begins after exposure to a traumatic event. Despite recommended various therapeutic approaches, including both pharmacotherapy and psychotherapy, treatment is not as effective as expected. Over recent years the pharmaceutical industry has not been able to offer a new approach, founded on multiple mechanisms of action. That is why a part of researchers focused on psychoactive substances synthesized years ago and then banned. These days MDMA-assisted psychotherapy for the treatment of PTSD clinical trials are conducted, and due to previous results, the Food and Drug Administration (FDA) granted a breakthrough therapy designation. In this article, we present the mechanism of actions, the therapeutic rationale, applied psychotherapeutic methods, and potential dangers. If ongoing phase 3 studies are completed and clinical efficacy criteria are achieved, the FDA could approve the treatment as early as 2022.