From Pharmacy Drug Guide
Marijuana is a mild hallucinogen that is made from the leaves, stems, seeds, and flowers of the Cannabis sativa or Cannabis indica plant. The cannabis is dried and then shredded or crushed before being smoked or otherwise consumed. Marijuana is the most commonly-used illegal drug in the United States.
In some states, marijuana has been approved for medical use. In these regions, the drug is recommended by physicians to treat glaucoma, HIV, wasting syndrome brought by AIDS or other illnesses, chronic or severe pain, nausea, migraines, and side effects from chemotherapy. While medical marijuana users may be safe from state prosecution in those states, they do still face potential federal criminal penalties, since all marijuana use is prohibited under federal law.
|Street names||Pot, herb, weed, grass, ganja, Mary Jane, reefer, chronic|
|Active chemicals||THC (delta-9-tetrahydrocannabinol)|
|Delivery method||Smoked, vaporized or eaten|
|Side effects||Hunger, thirst, anxiety, paranoia|
|US DEA Classification||Schedule I|
|Disclaimer||The information provided by PharmacyDrugGuide is not a substitute for professional medical advice, diagnosis, or treatment. Do not take any action based on the information on this page without consulting a physician.|
Physiologic Effects of Marijuana
The effects of marijuana vary depending on the percentage of THC the marijuana contains, the amount consumed, and the method used to consume it. The effects may also be influenced by the expectations of the user, how often the user has used marijuana before, what type of setting the drug is taken in, and whether any other drugs or alcohol are being consumed at the same time.
Most users will experience a sense of euphoria or relaxation (known as the "high" feeling), which will be accompanied by an increased heart rate, bloodshot eyes, and a dry mouth. Some users get hungry (a phenomenon called "the munchies"), some get thirsty, and some get both hungry and thirsty. 
Since marijuana is a psychoactive drug, users can expect to have problems with memory, judgment, and mobility while under the influence of marijuana. According to the National Institute on Drug abuse, some of the effects on memory may last days or weeks after using marijuana.
Senior Citizens and Medical Marijuana
Marijuana Legal Status
While it is illegal to sell or possess marijuana under federal law, a number of states have decriminalized marijuana. Additionally, some states have legalized marijuana for medical purposes. However, there is no federal exception for medical marijuana, and distributors abiding by local and state law may still be subject to prosecution by the federal authorities. The Drug Enforcement Administration (DEA) has performed crackdowns on growers and marijuana dispensaries, destroying crops and closing down retailers.
There are two main varieties of marijuana: sativa and indica. Indica was first harvested in Afghanistan, Tibet, and Morocco, and has stockier plants with wide leaves. Indica is described as producing a relaxing high. Sativa is the other main strain, and these plants tend to be taller and lankier that indicas. They first appeared in Mexico, Colombia, and Southeast Asia, and the "high" produced from sativa is described as energizing and cerebral.
While many strains of marijuana are either pure sativa or pure indica, growers also may breed these two varieties together. The resulting plants are known as hybrids. These hybrids may be cultivated to contain equal parts of each strain, or may be heavier on either the indica or the sativa side.
The price of marijuana varies according to strain and location. Costs have been reported at between $25 to $60 for an eighth of an ounce at medical marijuana dispensaries.
As with any drug, marijuana use poses a risk for potential abuse. 2010 data from the National Institute on Drug Abuse reported 11.5 percent, or 29 million Americans, said they abused marijuana. Abuse occurs when they cannot stop using it, despite negative consequences that getting high may have on their lives. Among students, those who smoke marijuana tend to have lower grades and a higher dropout rate. 
Marijuana is classified as a schedule I controlled substance by the DEA, meaning they view it as having a high potential for abuse with no approved medical use. Despite this, the FDA has approved pharmaceuticals that contain THC, the active ingredient in marijuana. Other Schedule I drugs include heroin, ecstasy and peyote.