Ketamine (esketamine) is a dissociative hallucinogen and anesthetic. It also possesses analgesic, sedative, and antidepressant properties.
Ketamine is legal and available by prescription in the US, UK, Canada, and Australia. The drug is FDA approved as an anesthetic and sedative, with trials currently ongoing for use as an antidepressant. It is already being used off-label as a treatment for depression.