THC
Definition: THC, short for delta-9-tetrahydrocannabinol, is the primary intoxicating cannabinoid in marijuana. The living plant makes it in acid form, THCA, which converts to THC when heated by smoking, vaping or baking. THC binds to CB1 receptors in the brain and is associated with the high people commonly report, including euphoria and altered perception.
How THC works
Chemists Raphael Mechoulam and Yehiel Gaoni isolated THC and described its structure in Israel in 1964. That work later led scientists to the body’s endocannabinoid system and the CB1 receptor, which is concentrated in the brain and nervous system.
How THC is measured
Lab reports usually list both THC and THCA. Because raw flower is mostly THCA, labs calculate total THC as THC plus THCA multiplied by 0.877, a factor that accounts for the weight lost when THCA becomes THC. Modern flower commonly tests between 15 and 30% total THC.
What affects THC in your harvest
- Genetics: sets the ceiling, and no technique pushes a plant past it.
- Light: strong light in flowering supports full resin production.
- Harvest timing: THC content tends to peak when most trichomes are cloudy.
- Storage: heat, light and air slowly degrade THC into CBN, so keep cured flower cool, dark and sealed.
Effects in context
Commonly reported effects include euphoria, relaxation, increased appetite and an altered sense of time. Users also report dry mouth, red eyes and, at higher doses, anxiety or paranoia. Responses vary widely with dose, tolerance, and the terpenes and other cannabinoids present. THC percentage alone is a rough guide to strength, not a full description of the experience.