Marijuana has many harmful effects in humans. The active compound of marijuana, THC is passed throughout the body through blood. THC is absorbed by the tissues and organs of the body. When compared to the blood, the concentration of THC is more in milk of nursing mothers. The component however is primarily found in fat tissues. In order to destroy the harmful chemical component, the body, through some chemical and physical processes, converts it into metabolites. As THC is a fat soluble compound, it takes more time to excrete it from the body. These THC metabolites are sent out through urine. So when urine tests are conducted on marijuana consumed people, the metabolites of THC are detected for about one week after the consumption. When radioactive tests are used for the drug consumption, THC can be detected for one month. After the test, 40 percent of the radioactive labeled THC stays in the body for three days and about 30 percent of it remains till one week. The presence of the drug in the body is based on the metabolism rate of a person. It was revealed that in people having 8%-12% of body fat the excretion of the toxic metabolites is faster and so THC metabolites are lost faster than others.