THC (Tetrahydrocannabinol) gets a user high, a larger THC content will produce a stronger high. Without THC you don’t get high.
CBD (Cannabidiol) increases some of the effects of THC and decreases other effects of THC. High levels of THC and low levels of CBD contribute to a strong, clear headed, more energetic high.
Cannabis that has a high level of both THC and CBD will produce a strong head-stone that feels almost dreamlike. Cannabis that has low levels of THC and high levels of CBD produces more of a buzz or stoned feeling. The mind feels dull and the body feels tired.
When the plants are actively flowering, the resins contain a higher proportion of THC than during the vegetative stage. During the later stages, when flower production has slowed, THC is degrading to other related chemicals such as CBD. It is thought that THC is mainly responsible for the “high” and CBD for the more physical, “stony” sensations such as lethargy. If you want a clear high then harvest when approximately 35% of the pistils (little white hairs) have turned red or brown. If, on the other hand, you prefer the heavier hit you get from something like pakki-black resin then wait until 65% of the pistils have changed color.
CBN (Cannabinol) is produced as THC ages and breaks down, this process is known as oxidization. High levels of CBN tend to make the user feel messed up rather than high.
CBN levels can be kept to a minimum by storing cannabis products in a dark, cool, airtight environment.
THCV (Tetrahydrocannabivarin) is found primarily in strains of African and Asian cannabis. THCV increases the speed and intensity of THC effects, but also causes the high to end sooner. Weed that smells strong (prior to smoking) might indicate a high level of THCV.
CBC (Cannabichromene) is probably not psychoactive in pure form but is thought to interact with THC to enhance the high.
CBL (Cannabicyclol) is a degradative product like CBN. Light converts CBC to CBL.