The critical composition for pain relief is measured by the CBD/THC ratio.
At present, there are two known types of cannabinoid receptors, termed CB1 and CB2, with mounting evidence of more. The human brain has more cannabinoid receptors than any other G protein-coupled receptor (GPCR) type.
Cannabinoid receptor type 1
CB1 receptors are found primarily in the brain, to be specific in the basal ganglia and in the limbic system, including the hippocampus.
Cannabinoid receptor type 2
CB2 receptors are predominantly found in the immune system, or immune-derived cells with the greatest density in the spleen.
CB2 receptors appear to be responsible for the anti-inflammatory and possibly other therapeutic effects of cannabis.
Cannabidiol (CBD) is not psychoactive
recent evidence shows that smokers of cannabis with a higher CBD/THC ratio were less likely to experience schizophrenia-like symptoms.
Cannabidiol has also been shown to act as a 5-HT1A receptor agonist, an action that is involved in its antidepressant, anxiolytic, and neuroprotective effects.
It appears to relieve convulsion, inflammation, anxiety, and nausea. CBD has a greater affinity for the CB2 receptor than for the CB1 receptor.
CBD apparently plays a role in preventing the short-term memory loss associated with THC in mammals.
Cannabis indica may have a CBD:THC ratio 4–5 times that of Cannabis sativa
Cannabinol (CBN) is the primary product of THC degradation
Its affinity to the CB2 receptor is higher than for the CB1 receptor.