Ajulemic acid (AB-III-56, HU-239, IP-751) is a synthetic cannabinoid derivative of the non-psychoactive THC metabolite 11-nor-9-carboxy-THC that shows useful analgesic and anti-inflammatory effects without causing a subjective "high". It is being developed for the treatment of neuropathic pain and inflammatory conditions such as arthritis. It does not however share the anti-emetic effects of other cannabinoids but may be useful for treating pain and chronic inflammatory conditions where nausea is not present. Side effects include dry mouth, tiredness and dizziness. The mechanism of action has not yet been established, but ajulemic acid may activate the CB1 receptor in a different way to psychoactive cannabinoids. Studies in animals at 100x the dose used in human trials suggest that there is some psychoactivity of ajulemic acid, comparable to that produced by tetrahydrocannabinol, however there was no difference between ajulemic acid and placebo on the "cannabimimetic" assay when used in humans at therapeutic doses.