Cannabis contains more than 100 cannabinoids, but two are the main ones, and they have very different effects and legal status. These are THC (Tetrahydrocannabinol) and CBD (Cannabidiol). Each produces something different, and contributes both to the sensation produced by marijuana and to its therapeutic applications. Understanding both compounds allows you to better select the strain when growing, as well as knowing what to look for depending on whether you want something recreational or medicinal.
First, what they have in common: both THC and CBD are cannabinoids, and they act on the endocannabinoid system, which all mammals, including humans, possess. This is an intercellular communication system that is naturally activated to create homeostasis, but can be stimulated by phytocannabinoids, that is, plant-based cannabinoids, such as those found in the marijuana plant. These cause different effects than those that occur naturally in the body. The main receptors of the endocannabinoid system are CB-1 and CB-2, which are found in the central nervous system and the immune system.
THC is the psychoactive component of cannabis and binds to these two receptors in the human brain. CB-1 influences pleasure, appetite, memory, and concentration, while CB-2 moderates pain sensations and plays a role in homeostasis in certain parts of the body, such as the kidneys and liver. Furthermore, THC is the component responsible for making you crave pizza and go to sleep after smoking a joint. It increases appetite and enhances the feeling of pleasure when eating, and also causes drowsiness. This is why it is used in treatments for insomnia and loss of appetite. THC also affects short-term memory.
CBD, for its part, interacts with receptors such as GPR55 and 5-HT1A. It is not psychoactive, although it works in many ways with THC to contribute to the effect of cannabis. In fact, it counteracts THC's effects in several ways, so its proportion is important in determining the sensation produced by marijuana. CBD reduces the anxiety that THC typically causes and has antipsychotic properties that balance the stronger effects of the high.
CBD is also the most sought-after component in medicinal strains. It has anti-inflammatory properties far superior to those of THC and lacks the psychotropic effects, making it safe for all patients. It is widely used for conditions such as arthritis and rheumatism. CBD also has an anticonvulsant effect and reduces muscle spasms, which is why it is often prescribed for refractory epilepsy. It is also an anxiolytic and antipsychotic, with studies supporting its use in the treatment of schizophrenia.
Both cannabinoids play important roles and work perfectly together, regulating each other. Depending on the desired effect and use, you may choose strains richer in one compound or the other. If you're suffering from an illness or have taken a massive fall, you'll probably want a lot of CBD, but if your plan is to watch a movie and finish only a bag of chips, THC is your go-to. Just remember that without a good balance of CBD, you'll probably never finish the movie because you'll fall asleep or forget what it was about in the first place. The secret is in the right balance.
by 
