His discovery is actually almost 20 years back, but only today he gains attention and importance. Meanwhile, the receptor called GPR55 also becomes CB3, the third relevant cannabinoid receptor in the human endogenous cannabinoid system.
Endocannabinoid system
Until quite some time ago, we knew that THC, which resembles the endogenous cannabinoid anandamide, binds to receptors in the brain, and as a result has an effect on our body. In the meantime, we know about the endocannabinoid system, which allows humans to use endocannabinoids, which the body itself produces, to perform a variety of health and immune functions. This system also harnesses the cannabinoids that we infuse from the outside by taking cannabis.
The CB1 receptor
So far, two receptors are known, which are simply described with CB1 and CB2. The CB1 receptor can bind to both THC and CBD. Because they "compete" for the CB1 receptor during the effect of cannabis in the body, and CBD is not known to be psychoactive, CBD cushions the "high" effect of THC. These receptors are found mainly in the central nervous system, thus affecting the sensation of pain and also the motor skills, but also emotions, memory and appetite.
The CB2 receptor
The CB2 receptor is found in organs of the immune system, mast cells and lymphocytes. While cannabis is believed to affect the immune system, the assumption that CBD interacts directly with the CB2 receptor is outdated. Rather, it seems that the cannabinoids cause the body to use more of its own endocannabinoids.
CBD, GPR55 and cancer
The receptor GPR55, which was discovered in 1999 and can be found in the brain and peripheral nervous system, seems to be able to work with many different cannabinoids. It has differences to CB1 and CB2, but is 13 percent identical in construction to CB1 and 14.4 percent to CB2. One might now assume that cannabidiol (CBD) might dock specifically to the CB3 receptor. However, this does not seem to be the case, CBD even blocks the receptor. But this does not mean that CBD is useless for the receptor or for the medical influence of it, on the contrary. GPR55 signaling is said to be associated with the development or progression of cancer. Thus, the use of CBD targeted to block the signal transmission inhibit the growth of some tumors.
CBD, GPR55 and epilepsy
Although the diseases do not resemble each other, the apparent effect of CBD in epilepsy can be explained by the same principle as cancer. Among other things, GPR55 also occur in the hippocampus, the area of ​​the brain in which spatial orientation and long-term memory are located. CBD has shown significant improvements in the intensity, quantity, and duration of seizures in some forms of epilepsy.
CBD, GPR55 and irritable bowel syndrome
CBD also has a positive influence on this intestinal disease. Fast and permanent improvement of well-being and relief of symptoms is reported. And again, this is associated with inhibition of signal transduction from GPR55. But in irritable bowel syndrome, it is also the anti-inflammatory properties of CBD, the help in the most chronic stomach and intestinal disorders.
Only the beginning
Many details about the CB3 receptor and the role it plays in our health are still unclear. But this concerns the whole endogenous cannabinoid system and its receptors, the cannabinoids, whether endogenous or supplied, and the terpenes and their many interactions and possible interactions with our bodies. But with every new insight, the accuracy with which we can use the properties of the cannabis plant for our health increases.


KLAUS GLASMANN, Dieter. GPR55 – Der neue Cannabinoid-Rezeptor. 1 [online] 30 Aug, 2019. Dostupné z: https://www.hanf-magazin.com/medizin/cannabinoide/gpr55-der-neue-cannabinoid-rezeptor/