Description and Composition

Cannabis is a drug derived from the cannabis plant. The following are some ways cannabis is taken:

  • Dried plants: marijuana (pot, buds, ganja, weed, grass)
  • Solid concentrates: hashish, rosin, dabs (wax, shatter)
  • Liquid concentrates: hash oil, vape cartridges, and oil for oral use

Cannabis can also be added to foods, often brownies, cookies, or chocolate.

Cannabis may be a natural drug, but that doesn’t mean it’s harmless. Using it may have adverse health effects. Cannabis contains over 500 different substances. We’ll look at two:

Tetrahydrocannabinol (THC)

Tetrahydrocannabinol (THC) is the main active ingredient in cannabis. It works by disrupting the nervous system of the person taking it. The THC present in cannabis isn’t psychoactive in its natural state; it has to be heated to be activated.

The more THC there is in a product, the stronger its effects. But the average concentration of THC in cannabis has been rising continuously for decades. In 1960 it was 1%, while in 2014 it passed the 12% mark.

Increasing THC concentrations mainly stem from

  • Better selection of cannabis plants and strains
  • New cultivation methods
  • Crossbreeding

Final THC concentration also depends on the form of cannabis:

  • Marijuana (for smoking): 5 to 25% THC
  • Hashish: up to 35% THC
  • Hash oil: up to 60% THC
  • Dabs (i.e., wax or shatter): up to 90% THC

Cannabidiol (CBD)

Cannabidiol (CBD) is another substance found in cannabis. It seems to lack the disruptive properties of THC, but researchers have recently taken a particular interest in CBD for its therapeutic potential.

CBD concentrations have however been declining steadily, relative to THC, since the early 2000s, upsetting the balance between the two substances. Some experts have suggested that CBD may influence the action of THC. Specifically, it may tend to reduce the likelihood or severity of possible negative psychological effects from THC, such as anxiety, psychosis, or dependency.


ELSOHLY, Mahmoud A et al. Phytochemistry of Cannabis sativa L.. In: Kinghorn A., Falk H., Gibbons S., Kobayashi J. (eds) Phytocannabinoids. Progress in the Chemistry of Organic Natural Products, vol. 103, 2017, p. 1-36. Springer, Cham.

SMART, Rosanna et al. Variation in cannabis potency and prices in a newly legal market: evidence from 30 million cannabis sales in Washington state. Addiction, vol. 112, no 12, 2017, p. 2167-2177.

Last update: March 30, 2023 11:12 AM