After collection from the plant this secretion is normally dried and then compressed into a variety of forms, normally balls or cakes. It has different names in around the world but is actually the same old hashish. 

Marijuana is a green or gray mixture of dried, shredded flowers and leaves of cannabis, usually smoked as a cigarette (called a "joint" or a "nail") or in a pipe or bong. In recent years, marijuana has appeared in blunts (cigars emptied of tobacco and refilled with marijuana) of ten in combination with another drug, such as crack. A less popular way of use is to add marijuana to food or to brew tea.

The plant contains the alkaloids cannabinol, cannabidiol, etc. but the chief active ingredient is called delta-9-Tetrahydro-cannabinol (THC). It has been discovered that the membranes of certain nerve cells contain receptors that bind THC. This interaction induces a series of cellular reactions responsible for the hallucinogenic effect of the substance. Although there is much variation of the content, a cigarette usually contains about 1g of marijuana, or 20 mg THC. About 300 mg of the drug is equivalent to 70 g of alcohol. THC is absorbed rapidly by the nasal or oral routes, producing a peak of subjective effect at 10 minutes and 1 hr, respectively.

There are over 200 slang terms for marijuana including pot, herb, grass, weed, Mary Jane, boom, etc.   Cannabis sativa

Clinical manifestation of intoxication: short-term effects

In addiction to the “desired” effect of elation and euphoria, marijuana may impair short-term memory; hinder the performance of tasks requiring divided attenion (e.g. those involved in driving); cause a loss of critical judgement; and distort the perception of  time, sight, sound, and touch. Visual hallucinations and perceived body distortions occur rarely, but there may be “flashbacks” or frightening hallucinations, experienced under the influence of marijuana, that usually occur during stress or with fever. Body temperature may decrease. Increased heart rate is apparent within 20 minutes of marijuana smoking and is followed half an hour later by transient high blood pressure which disappears by the third hour. Loss of coordination and anxiety are also common toxic effects. Somnolence predominates in the late phase of intoxication.

Long-term effects of marijuana use

• Increased risk of cancer
• Respiratory problems: coughing and wheezing
• Increased risk of heart attack
• Weakening of the immune system
• Problems with learning, attention, and memory
• Emotional and behavioral problems
• Addiction in predisposed individuals, more often among teens
• Adverse effects on pregnancy
• Social problems among teenagers

The use of marijuana among teens is now rapidly escalating in the most industrialized nations. It is well known that there are many adults who “enjoy” a smoke once or twice a week without any major health consequences. It is the minority of heavy users who have lost control and whose physical and mental health is seriously damaged.

Nowadays, there are medicines based on pharmaceutical THC (such as Marinol), which are mostly used for the treatment of illnesses associated with wasting (such as AIDS and anorexia) and emesis associated with chemotherapy in cancer patients. There are also many fields under research related to other possible medical applications of THC, for example its anti-inflammatory effect. Most of these studies, however, are in their preliminary stages and need to be confirmed and extended to profound clinical studies.

For the time being, there are many opponents of the opinion that marijuana was harmful. Many campaigners and pressure groups accuse medical officials of conducting unscientific, politically oriented anti-dope propaganda. There is plenty of information on the Internet, on television, and in tabloid newspapers regarding the safety of marijuana or at least its harmlessness compared to tobacco and alcohol. However, the most reliable health institutions and world famous organizations such as the•World Health Organization (WHO) and the US National Institute of Drug Abuse have not changed their position regarding the use of marijuana. Most doctors agree with their concept. How about you?