Ketamine is available as a nasal spray at Psychiatry Unplugged. This is advantageous for a number of reasons; including the fact that it is the most extensively investigated type of ketamine treatment administration and has also been shown to be the most effective in treating depressive disorders. The spray is delivered nasally as a mist, which the patient inhales. Depending on individual metabolism, this has a very rapid onset and can induce results within minutes (and other factors).