It starts with how the medicine works. Ketamine’s predominant action in the human brain is to block the NMDA receptor, which normally activates neurons. When this receptor is block, the central nervous system begins to lose responsiveness. At lower doses, ketamine produces a mild state of hypnosis, pain relief, and alters the perception of sight and sound. Moderate doses begin to create illusions of separation from the environment or oneself and mild paralysis, commonly known as the “K-hole.” At escalating doses, it will cause near-complete paralysis, amnesia, and sedation, with preservation of the respiratory reflexes.