Hi Tanya   This is a very good question.  I am reading about this too.  Here is a long article from the Washington Post from several years ago about Special K or Ketamine.   And here is more information about the various studies which have been done on this substance.   Here is a site which posts about the updates to the legal status of this substance...it seems it is still illegal.   Here is what the National Drug Intelligence Center has to say about Ketamine:    Is ketamine illegal? Yes, it is illegal to abuse ketamine. Ketamine is a controlled substance. Specifically, it is a Schedule III substance under the Controlled Substances Act. Schedule III drugs, which include codeine and anabolic steroids, have less potential for abuse than Schedule I (heroin) or Schedule II (cocaine) drugs. However, abuse of Schedule III substances may lead to physical or psychological dependence on the drug.     From what I am reading...it is a drug which is sometimes used by sexual predators to give to their victims.    And it can cause cognitive impairments such as to memory.   I hope this helps some.  Thank you for your question.