Cannabinol (CBN) is one of the many cannabinoids found in the cannabis plant. Unlike CBD or CBG, CBN has psychoactive properties (however, quite mild compared to those of THC.) It is a partial agonist for CB1 receptors, but more so for CB2 receptors. Unlike many other cannabinoids, the majority of CBN is not derived directly from CBG; rather, it is derived from aged or air-exposed THC after the cannabis has already been harvested. Because CBN is a product of degradation and oxidation, most cannabis strains do not have high concentrations of CBN. Strains with high CBN may be an indication of the cannabis being relatively old or having been stored poorly.
CBN was first isolated in the 19th century, but its structure was not fully identified until 1930 by Robert Sydney Cahn. It was first chemically synthesized in 1940 by R. Adams in the United States and Lord Todd in the United Kingdom. CBN was one of the first cannabinoids to be involved in pharmacological experiments in the 1940s and 1950s, along with THC and CBD. In these experiments, THC was found to induce catalepsy in mice, CBD did not induce catalepsy in mice, and CBN also induced catalepsy in mice, but only at very high doses. These observations were the first indications that CBD is not a psychotropic agent and that CBN is a much milder psychotropic agent than THC. Despite its psychotropic features, CBN is often considered to be a non-intoxicating cannabinoid.
CBN is not scheduled under the 1961 UN Convention on Narcotic Drugs or the 1971 UN Convention of Psychotropic Substances. In the United States, CBN is not scheduled under the Controlled Substances Act. In Canada, CBN is scheduled under the Controlled Drugs and Substances Act as a Schedule II drug.
CBN is typically considered to be a sleep-inducing cannabinoid, but there is little evidence to validate this claim. One study showed that CBN increases the effects of THC, which may account for its reputation as being a sleep-inducing agent. In another study, CBN proved to be an effective anti-bacterial agent against a strain of antibiotic-resistant bacteria. CBN may also be a useful neuroprotectant, which could be promising for reducing symptoms in diseases like ALS. CBN has also been shown to be an effective appetite stimulant in mice, but more research needs to be done on human subjects. As well, one study found CBN to be an effective anti-inflammatory agent. CBN may also be useful in treating seizures and treating burns and promoting bone growth.
While these studies may seem promising, more research is needed before any of these claims can be considered conclusive.
Because CBN can increase the effects of THC, its adverse effects may be similar to its precursor: drowsiness, sluggishness, etc. The long term adverse effects of CBN are relatively unknown.