What do people describe?
Published descriptions of ibogaine experiences commonly refer to a prolonged and intense psychoactive period, often with nausea, vomiting, impaired coordination, and vivid changes in perception. Duration, intensity, and meaning can vary substantially from person to person.
Those descriptions should not be confused with evidence that an experience is safe or effective. The pharmacology and history of the substance are summarized in the Wikipedia overview of ibogaine, while the practical safety questions depend on an individual’s health, substances used, and the environment.