Snorting is the most popular. The user cuts the cocaine into lines and snorts it through one or both nostrils using a straw or a rolled up piece of paper. Others inject it directly into the blood stream. Crack is another type of cocaine. It is a hardened, very addictive form that may be smoked directly. Cocaine is very expensive. A single dose may be as little as a quarter of a gram, but it can easily cost $25 on the street. There are no currently approved uses for marijuana in the Unites States. However, many doctors obtain THC from the federal government under special arrangements in order to prescribe it for cancer patients. THC is effective in reducing the nausea that cancer patients suffer from. Marijuana may stimulate appetite. Marijuana may be smoked or taken by mouth. The same dose of THC is about three times as effective when smoked as when ingested. Marijuana is smoked in the form of a hand-rolled cigarettes, but it is also smoked in a variety of pipes. After smoking marijuana, the user has a "high," including an increased sense of well-being, relaxation, and sleepiness. Most users learn to avoid overdosage by taking only as many inhalations as required to produce the desired "high." Steroids may have some therapeutic value. The United States Food and Drug Administration has approved the use of selected steroids for treating specific types of anemia, some breast cancers, osteoporosis, endometriosis, and hereditary angioedema, a rare disease involving the swelling of some parts of the body. Steroids are used today by young people that are in a hurry to reach maturity or by someone that hates his skinny body. Most of all, steroids are used by athletes to build muscle mass. They also help muscles to recuperate more quickly from exhaustion or injury. These enable users to train more frequently and for longer periods of time at a high intensity. Athletes generally take the drugs in dosages 10 to 100 times greater than would be prescribed for therapeutic purposes.