Pregnenolone is an endogenous steroid and precursor the biosynthesis of most of the steroid hormones, including the progestogens, androgens, estrogens, glucocorticoids, and mineralocorticoids. In addition, pregnenolone is a precursor of neurosteroid pregnenolone sulfate, which is positive modulator of NMDA receptors and negative modulator of GABAA. Pregnenolone itself is a negative allosteric modulator of cannabinoid receptors. Pregnenolone is available as a dietary supplement, and is being investigated in clinical trials agains schizophrenia, bipolar disorder, major depressive disorder, marijuana dependency and other conditions.

Pregnenolone is an endogenous steroid and precursor the biosynthesis of most of the steroid hormones, including the progestogens, androgens, estrogens, glucocorticoids, and mineralocorticoids. In addition, pregnenolone is a precursor of neurosteroid pregnenolone sulfate, which is positive modulator of NMDA receptors and negative modulator of GABAA. Pregnenolone itself is a negative allosteric modulator of cannabinoid receptors. Pregnenolone is available as a dietary supplement, and is being investigated in clinical trials agains schizophrenia, bipolar disorder, major depressive disorder, marijuana dependency and other conditions.

CB-13 is a cannabinoid drug, which acts as a potent agonist at both the CB1 and CB2 receptors, but has poor blood-brain barrier penetration, and so produces only peripheral effects at low doses, with symptoms of central effects such as catalepsy only appearing at much higher dose ranges. CB-13 displays antihyperalgesic activity in a rat model of neuropathic pain with no CNS side effects.

Rimonabant (also known as SR141716; trade names Acomplia, Zimulti) was an anorectic antiobesity drug that was first approved in Europe in 2006 but was withdrawn worldwide in 2008 due to serious psychiatric side effects. Rimonabant is an inverse agonist for the cannabinoid receptor CB1 and was the first drug approved in that class. There is considerable evidence that the endocannabinoid (endogenous cannabinoid) system plays a significant role in appetitive drive and associated behaviors. It is, therefore, reasonable to hypothesize that the attenuation of the activity of this system would have therapeutic benefit in treating disorders that might have a component of excess appetitive drive or over-activity of the endocannabinoid system, such as obesity, ethanol and other drug abuse, and a variety of central nervous system and other disorders. Data from clinical trials submitted to regulatory authorities showed that rimonabant caused depressive disorders or mood alterations in up to 10% of subjects and suicidal ideation in around 1%, and in Europe, it was contraindicated for people with any psychiatric disorder, including depressed or suicidal people. Additionally, nausea and upper respiratory tract infections were very common (occurring in more than 10% of people) adverse effects; common adverse effects (occurring in between 1% and 10% of people) included gastroenteritis, anxiety, irritability, insomnia and other sleep disorders, hot flushes, diarrhea, vomiting, dry or itchy skin, tendonitis, muscle cramps and spasms, fatigue, flu-like symptoms, and increased risk of falling.