Basics
How cannabis works in the body
The endocannabinoid system and why cannabis has effects.
The endocannabinoid system
The human body has a signaling system called the endocannabinoid system (ECS). It is made of receptors (mainly CB1 and CB2), molecules the body makes itself (endocannabinoids such as anandamide), and the enzymes that regulate them. The ECS helps keep the body in balance —what scientists call homeostasis— and influences processes such as sleep, appetite, mood, memory, and pain perception.
Where cannabis acts
Cannabis compounds (cannabinoids such as THC and CBD) have a shape similar to the body's own endocannabinoids, so they can interact with the same receptors. CB1 receptors are abundant in the brain and nervous system; CB2 receptors are found more in the immune system. THC binds directly to CB1, which explains its psychoactive effects. CBD acts more indirectly and does not cause intoxication.
Why dose matters
Cannabis does not act the same in every person or at every dose. Genetics, weight, tolerance, the method of use, and even the time of day change the response. That is why medical cannabis follows the principle "start low and go slow": begin with the lowest effective dose and adjust over time, always under your physician's guidance.
Educational information only — not medical advice. Medical cannabis in Puerto Rico is for registered patients 21+ under an authorized physician's recommendation. Talk to your doctor before any treatment decision.