|Drug||CB1 target||CB2 target||Oral bioavailability||Half life||Effect|
|Δ9-Tetrahydrocannabidiol (THC)||Partial agonist||Partial agonist||6-20%||25-36 hoursNote 1||Psychoactive|
|Cannabidiol (CBD)||Antagonist||Antagonist||13-19%||9 hoursNote 1||Non-psychoactive|
|Cannabinol (CBN)||Partial agonist (weak)||Partial agonist (weak)||Psychoactive|
1 THC and CBD synergize pharmacokinetically, each extending the half life of the other. Pure THC will have a shorter half life when administered by itself, as opposed to a mixture of THC and CBD. At the same time, THC and CBD counteract one another pharmacodynamically, resulting in a less intense, but more long lasting, subjective "high" in recreational users.
Agonists of the human CB1 receptor are typically psychoactive. They are similar to the endogenous compound anandamide.
- Tetrahydrocannabidiol (THC): CB1 receptor agonist or partial agonist. Main compound responsible for the psychoactive effects of cannabis.
- Cannabinol (CBN): partial agonist.
CB1 antagonists are nonpsychoactive, but have a variety of health benefits and uses as medication.
- Cannabidiol (CBD): CB1 receptor antagonist. Responsible, at least in part, for many of the medicinal properties of cannabis.
- Cannabidivarin (CBDV)
- Cannabigerol (CBG)
- Tetrahydrocannabivarin (THCV)
- Cannabichromene (CBC)
- Cannabicyclol (CBL)
- Anandamide is considered to be an analog of Δ-9-THC. It is found naturally in the human body.
- 2-Arachidonoylglycerol is another agonist.
- Virodhamine is a naturally occurring CB1 antagonist and CB2 agonist.
See also: List of Cannabinoids at Wikipedia.
- dronabinol (Marinol) is a synthetic version of THC, approved by various regulatory agencies.
- ibipinabant - highly selective antagonist of CB1 developed by pharmaceutical labs, but never marketed.
- otenabant is another highly selective antagonist of CB1 receptors. Originally developed by Pfizer, but never marketed.
- rimonabant is a CB1 inverse agonist and a μ-opioid receptor antagonist. Marketed under the brand names Acomplia and Zimulti. Approved by UK and EU regulatory agencies but not by the US FDA, rimonabant is no longer widely recommended due to the association with psychiatric problems including suicide ideation. However, its activity at the μ-opioid receptor may be responsible for the negative side effects.
- N-arachidonoylaminophenol (AM404) is a metabolite of acetaminophen/paracetamol (Tylenol), which may be responsible for some or all of its analgesic effects. AM404 is believed to inhibit the internalization of anandamide in the body, causing a modest increase in endocannabinoid activity. It is therefore possible that the effect of acetaminophen in relieving pain can be compared to small doses of THC, or the paradoxical effects of CBD.
- nabilone (Cesamet) is usually promoted as being similar to THC in its medicinal effects, but users anecdotally report its effects to be more like those of cannabidiol. The drug appears to have less of an effect on CB1 receptors than THC.
Terpenes, although not classified as cannabinoids, are found in the cannabis plant and are responsible for part of the psychoactive effects of cannabis.
- myrcene is a terpene with sedative and analgesic effects. It also potentiates THC by aiding its passage over the blood-brain barrier, and increasing the maximum level of saturation of the CB1 receptor. Myrcene is responsible for the "couch lock" effect of many cannabis strains. Myrcene is also found in mangoes and other foods, and eating a ripe mango about an hour before cannabis consumption has been anectdotally reported to enhance the psychoactive effects of cannabis.
- pinene is a terpene found in small amounts in cannabis. Strains higher in pinene are believed to produce a more "functional" high, counteracting the short-term memory deficit caused by THC.
- limonene is a terpene found in cannabis, and citrus fruits such as lemons, limes, and oranges. It is believed to have antidepressant, anxiolytic, and immunostimulant properties, and may be beneficial in reducing acid reflux.
- linalool boosts the relaxing effects of cannabis. It may also have medicinal properties for Alzheimer's Disease patients.
- caryophyllene has anti-inflammatory, antioxidant, and antinociceptive (analgesic) effects. It is believed to be a CB2 receptor agonist.