This is a relatively mild, non-addictive drug with hallucinogenic properties, obtained from the flowering tops, stems, and leaves of the hemp plant. Resins found on the surface of the female plant are used to prepare the most potent form of marijuana, hashish.

The primary active substance is tetrahydrocannabinol (THC). Marijuana produces a dreamy, euphoric state of altered consciousness, with feelings of detachment and gaiety. The appetite is usually enhanced, while the sex drive may increase or decrease depending on the company you are smoking in.

Adverse reactions are relatively rare, and most can be attributed to adulterants frequently found in marijuana preparations. Marijuana is the most widely used illicit drug in the world and tends to be the first illegal drug teenagers use. The physical effects of marijuana use, particularly on developing adolescents, can be acute. For example sleepiness, difficulty keeping track of time, impaired or reduced short-term memory, reduced ability to perform tasks requiring concentration and co-ordination, increased heart rate, bloodshot eyes, decreased social inhibitions, paranoia, hallucinations. However, researchers have as yet been unable to determine conclusively whether these are the effects of cannabis use, or a side effect of the condition of adolescence.

The effects of cannabis are not totally disimilar from those of alcohol. The main difference is that cannabis promotes feelings of immense relaxation, warmth, love and friendship, which, over a night-long session usually leads into a deep and satisfying sleep with remarkably lucid dreams, whereas alcohol promotes all of these feelings but usually leads into a senseless and often painful argument, followed by a comatosed sleep and a visitation during the night by the bringer of cotton mouth.

The main difference, however, is that in most countries, cannabis is illegal while alcohol is not.