THC is the main psychoactive component of cannabis, and one of a class of compounds
known as cannabinoids.
Cannabis tends to be relatively low in THC compared to its levels of a THC precursor,
Heating the cannabis plant, however, causes the conversion of THCA to THC, which is part
of the basis for heating or burning the plant for use.
The effects of cannabis may vary depending on the variety of cannabis plant and its associated
levels of THC and other cannabinoids, but common effects of THC include: euphoria, sedation,
stimulation of appetite, impaired cognitive function, analgesia, and anxiety.
THC is thought to exert most of its effects by binding to receptors called cannabinoid
There are two known cannabinoid receptors, CB1 and CB2---both of which are g-protein coupled
CB1 receptors are found throughout the nervous system, while CB2 receptors are primarily
found on immune cells.
THC acts as a partial agonist at cannabinoid receptors, meaning it binds to these receptors
and generates a response that’s a fraction of what other substances that bind to the
receptors can generate.
THC interacts with a number of other targets as well, but it’s thought that its main
psychoactive effects are mediated through its action at CB1 receptors.
Activation of CB1 receptors is thought to lead to the modulation of the release of various
It’s not fully understood how this translates into the characteristic effects of THC, but
the activation of CB1 receptors in different areas of the nervous system may partially
explain the effects of the drug.
CB1 receptors in areas like the cortex and hippocampus, for example, may be involved
in the perceptual and cognitive effects of THC. CB1 receptors in areas like the basal
ganglia and cerebellum may be associated with sedation and effects on movement. And CB1
receptors in areas like the spinal cord and brainstem may be linked to analgesic effects.