Marijuana, also known as cannabis or pot, among many other names, has a long history of human use.
The cannabis or hemp plant evolved in Central Asia before people introduced the plant into Africa, Europe, and eventually the Americas. People didn’t grow the plant to get high, but as herbal medicine, likely starting in Asia around 500 BC. Fiber from Hemp was used to make clothing, paper, sails, and rope, and its seeds were used as food.
The fast-growing nature of the plant made it easy to cultivate and has many uses. In the early 1600s, the Virginia, Massachusetts and Connecticut colonies required farmers to grow Hemp.
The psychoactive compound of cannabis is known as tetrahydrocannabinol (THC), one of 483 known compounds in the plant. Marijuana can be used by smoking, vaporizing, within the food, or as an extract.
The early culture of Hemp plants had very low levels of tetrahydrocannabinol (THC). The amount of THC in marijuana has dramatically increased in recent decades. The average THC content of confiscated weed in the mid-1990s was about 4 percent. However, by 2014, it became12 percent, with a few strains of the pot containing THC levels as high as 37 percent.
There is evidence that ancient cultures are aware of the psychoactive properties of the plant. They might have cultivated some strains to produce higher levels of THC for use in religious ceremonies or healing practice.
For more: Medical Marijuana