How Medical Marijuana Works

A customer at a cannabis dispensary in San Francisco holds a marijuana cigarette.  See more controlled substance pictures.
A customer at a cannabis dispensary in San Francisco holds a marijuana cigarette.  See more controlled substance pictures.
Justin Sullivan/Getty Images

In an ad that aired on TV in New York, a man named Burton Aldrich stares at the camera and tells the viewer, "I am in extreme pain right now. Everywhere. My arms, my legs, are feeling like I'm dipped in an acid." Aldrich is a quadriplegic confined to a wheelchair, and the best treatment for his overwhelming pain, he says, is marijuana. He continues, "Within five minutes of smoking marijuana, the spasms have gone away and the neuropathic pain has just about disappeared."

­­To some, medical marijuana is a contradiction in terms, immoral or simply illegal. But to Aldrich and numerous people in the United States and around the world, marijuana, or cannabis, represents an essential medicine that alleviates debilitating symptoms. Without it, these people wouldn't be able to treat their conditions. Aldrich thinks he would be dead without marijuana. Others, like Dr. Kevin Smith, who was also featured in these pro-medical marijuana ads, can't treat their conditions for fear of breaking the law. Smith says that, save for a trip to Amsterdam where he tried marijuana, the autoimmune disorders he suffers from have prevented him from sleeping soundly through the night for the last 20 years.


In states in which it's legal, doctors recommend medical marijuana for many conditions and diseases, frequently those that are chronic. Among them are nausea (especially as a result of chemotherapy), loss of appetite, chronic pain, anxiety, arthritis, cancer, AIDS, glaucoma, multiple sclerosis, insomnia, ADHD, epilepsy, inflammation, migraines and Crohn's disease. The drug is also used to ease pain and improve quality of life for people who are terminally ill.

So how, exactly, does medical marijuana work to treat these conditions? Why, if this medicine is so effective for some people, does it remain controversial and, in many places, illegal? In this article, we'll take a look at the medical, legal, and practical issues surrounding medical marijuana in the United States. We'll examine why some people, like Burton Aldrich, depend on it to live normally. We'll also examine some of the intriguing intersections between pharmaceutical companies, the government and the medical marijuana industry.


Making a Case for Legal Medical Marijuana

An assistant studies marijuana leaves in the Maripharma Laboratory in Rotterdam, Netherlands.
An assistant studies marijuana leaves in the Maripharma Laboratory in Rotterdam, Netherlands.
Michel Porro/Getty Images

One common question associated with medical marijuana is why use it when so many other legal medications are available? Supporters respond that patients don't simply use cannabis to feel good. Instead, laws that authorize marijuana use for medical purposes work on the belief that certain symptoms and diseases can be best treated with marijuana -- just as two Tylenol may help someone's headache.

For example, marijuana has been shown to decrease nausea and increase appetite, which can be essential for patients who are having difficulty keeping down food or maintaining adequate nutrition. For glaucoma sufferers, marijuana helps to lower intraocular eye pressure. Also, some types of pain, such as peripheral neuropathy, respond better to marijuana than conventional pain relievers [source: Grinspoon]. For some cancer and AIDS patients, drugs that are supposed to boost appetite simply don't work. Other patients are tired of using medications that can be considered narcotic, addictive, or dangerous, or that produce unpleasant side effects.


The body of research surrounding the medicinal value of marijuana is extensive. Much of it concerns THC, one of the cannabinoids in marijuana. THC is what causes people to feel "high" and also what gives cannabis some of its medicinal properties, such as increased appetite. The human body produces endocannabinoids, its own natural version of cannabinoids. Studies show that the endocannabinoid system helps to regulate the body's responses "to a variety of stimuli" [source: Nature]. The body will produce endocannabinoids when needed, but sometimes the effect is very brief. Endocannabinoid receptors are found throughout the body but are especially prominent in the brain. The cannabinoids in marijuana, like THC, bind to these receptors, producing various effects, some medicinal, such as reducing pain or anxiety, but also the feeling of being high. Besides the aforementioned medical uses, research has shown that cannabinoids slow the development of certain cancers [source: Armentano­].

­One popular strain of research examines how to extract the medical benefits of cannabis without producing intoxication. One such medication already exists: the pain reliever Sativex, based on a natural extract of marijuana and administered as an oral spray.

Then there is Marinol, which the DEA describes as the already existing, legal form of medical marijuana [source: DEA]. Approved by the FDA and used for treatment of nausea in cancer and AIDS patients, Marinol is a pill containing a synthetic form of THC. The DEA says that the legal use of Marinol is analogous to morphine being a legal, safe alternative to smoking opium or heroin [source: DEA]. (Morphine is one of many approved medicines extracted from opium.)

But some experts consider Marinol and other synthetic substitutes to be less effective -- and more expensive -- than marijuana. Medical marijuana advocates say that Marinol is a less complete version of marijuana, lacking some of the compounds that make marijuana medically beneficial [source: NORML]. Smoking herbal marijuana provides patients with a faster acting medication, one whose dosage they can easily regulate. Marinol may also be more psychoactive than traditional cannabis and present its own set of side effects [source: NORML].

On the next page, we'll take a look at the legal issues surrounding medical marijuana.

Medical Marijuana Laws in the U.S.

A DEA officer holding a marijuana plant
A DEA officer holding a marijuana plant
Doug Menuez/Photodisc/Getty Images

America's first pro-medical marijuana laws were passed in the 1970s. Since then, many such laws have been passed, modified or repealed. Currently, 12 states have medical marijuana laws: Alaska, California, Colorado, Hawaii, Maine, Montana, Nevada, New Mexico, Oregon, Rhode Island, Vermont and Washington [source: Drug Policy Alliance Network]. Maryland has a law authorizing medical marijuana use, but it doesn't allow patients to grow their own marijuana, and patients can still be fined under the law.

Despite these regulations, federal law supersedes state law, so someone can still be arrested and prosecuted for using or possessing medical marijuana, even if it's legal under state law. State laws generally don't legalize buying and selling of marijuana (at least not for profit), but they do legalize possession of it for medical use, following a doctor's recommendation. Medical marijuana laws usually protect from prosecution people designated as caregivers, such as those who take care of sick friends or family members and supply them with medical marijuana. (Again, most laws have a restriction against caregivers' reaping a profit from distributing medical marijuana.) Some of these laws also specify a list of conditions for which marijuana can be recommended.


Another 12 states have laws authorizing some form of medical marijuana research. Thirty states have laws that recognize marijuana's "medical value" [source: Marijuana Policy Project]. Some states have passed laws that have been made ineffective through repeal, overriding federal standards or "watered down" legislation. For example, some state laws authorize doctors to prescribe marijuana for medical use, but since it remains illegal under federal law to prescribe the drug -- and pharmacies can't supply it -- the laws are effectively void.

Let's use Washington as a brief example of one of the 12 states with "effective" medical marijuana laws. The state's Medical Marijuana Act allows a patient, with doctor's recommendation, to grow marijuana for his or her own use -- but only an amount that can be considered, at most, a 60-day supply [source: Washington Citizens of Medical Rights]. The doctor's recommendation is considered valid so long as the doctor continues to act as the patient's health care provider and doesn't revoke the recommendation.

On the next page, we'll take a look at California, the figurative poster child of medical marijuana in the U.S., and at what the FDA has to say about the drug.

Test Case: Medical Marijuana in California -- and the FDA's Opinion

DEA raids on medical marijuana dispensaries, like this one in Los Angeles, often attract medical marijuana activists, who protest the federal crackdowns.
DEA raids on medical marijuana dispensaries, like this one in Los Angeles, often attract medical marijuana activists, who protest the federal crackdowns.

­If the medical marijuana movement has a capital, then it's in California. In America's most populous state, where medical marijuana was made legal in 1996 by Proposition 215, an entire industry has sprouted up around medical marijuana. There, patients can grow, possess and use marijuana for medical purposes -- after a doctor's recommendation. A patient's primary caregiver may also provide marijuana, though many patients turn to marijuana dispensaries.

A 2003 bill updated the law. Now a patient with a note from his or her doctor can grow up to six plants or possess no more than half an ounce of marijuana. But individual counties can also set their own regulations, causing some, like Humboldt County, to relax their standards further. Because of these relatively liberal regulations, numerous medical marijuana dispensaries or co-ops operate throughout the state and in accordance with state law. However, growers, dispensaries and other middlemen often come into conflict with the federal government and federal law enforcement agencies, who conduct periodic raids on larger suppliers. Even so, the federal government almost never arrests actual patients for using medical marijuana.


Many Americans and states share California's opinion that marijuana can be a regulated, monitored drug, medically beneficial when recommended by a physician. But what does the federal government think? Under the Controlled Substances Act, marijuana is a Schedule I drug, the strictest classification. To give you an idea of what that means, heroin, LSD and Ecstasy are also Schedule I. The FDA classifies it as such because "marijuana has a high potential for abuse, has no currently accepted medical use in treatment in the United States, and has a lack of accepted safety for use under medical supervision" [source: FDA]. Medical marijuana advocates point to studies that dispute these claims and have filed numerous petitions asking for the FDA to reconsider marijuana's classification as a Schedule I drug.

The FDA's statement refers to evidence that smoking marijuana is harmful. The agency claims that medical evidence doesn't support marijuana as a viable treatment and that alternative treatments exist for most of the conditions that medical marijuana supposedly addresses. The FDA also says that state laws authorizing limited use of medical marijuana go against the stringent regulatory process mandated by the FDA, which is designed to ensure patient and consumer safety. Other federal entities, such as the DEA and Office of National Drug Control Policy, side with the FDA and don't support smoking marijuana for medicinal purposes.

A tin canister used by the U.S. government to provide medical marijuana to patients like Irv Rosenfeld. Rosenfeld is one of seven patients who currently receive medical marijuana grown and legally provided by the federal government.
A tin canister used by the U.S. government to provide medical marijuana to patients like Irv Rosenfeld. Rosenfeld is one of seven patients who currently receive medical marijuana grown and legally provided by the federal government.
Rod Rolle/Getty Images

The federal government did run a program from 1978 to 1992 that allowed select patients to receive medical marijuana. Only seven of the original patients are still alive and receiving marijuana through what was known as the IND Compassionate Access Program.

Now let's take a look at the practical side ­of medical marijuana, namely how patients receive it.


Getting Medical Marijuana: Dispensaries

Lucas Thayer holds his medical marijuana club card during a demonstration in front of the San Francisco Hall of Justice on July 12, 2005.
Lucas Thayer holds his medical marijuana club card during a demonstration in front of the San Francisco Hall of Justice on July 12, 2005.
Justin Sullivan/Getty Images

Since medical marijuana is illegal under federal law and pharmacies are prohibited from supplying it, doctors don't actually prescribe the drug. Instead, they "recommend" it to patients that they feel could benefit from it. (It's important to note that not all doctors support the medicinal use of marijuana and that doctors are only supposed to recommend it after determining that it can be medically helpful to the patient despite any side effects.)

Doctors who recommend medical marijuana write a letter explaining the patient's diagnosis and the doctor's choice of cannabis as treatment. Patients often keep this letter close at hand; some keep it with them at all times. A 2003 law in California allows the state to distribute ID cards to medical marijuana patients, which can serve in place of the recommendation letter.


A doctor's recommendation remains valid so long as the doctor continues to treat the patient and believes the patient should use the drug to treat a condition. Many dispensaries and pro-medical marijuana organizations maintain lists of doctors who are willing to recommend medical marijuana, although this practice has attracted controversy as some doctors appear willing, in exchange for a cash payment, to offer a recommendation for practically any condition.

Since marijuana can't be given out at a conventional pharmacy like Walgreens or CVS and insurance won't cover it, some patients cultivate their own marijuana or turn to a caregiver for their supplies. Others go to dispensaries, which can be legal, depending on state and local law. These dispensaries sometimes call themselves cannabis clubs or co-ops, or have names denoting health, physical therapy, caregiving or the like. Dispensaries often call themselves collectives, claiming that the marijuana sold there is grown by the members, who are all patients. Critics contend that many dispensaries in fact buy marijuana illegally and are open to abuse by people who don't need marijuana for medical reasons. Additionally, varying laws about how patients can get marijuana has created what some call a black market or "gray economy" of marijuana suppliers.

Marijuana-laced edibles are a popular alternative to smoking medical marijuana.
Marijuana-laced edibles are a popular alternative to smoking medical marijuana.
Bob Berg/Getty Images

Once a patient has a valid recommendation letter or ID card, he or she simply presents it at a dispensary. A patient may also have to join the dispensary as a member. Following that, he or she can purchase different types of herbal marijuana and numerous marijuana-based products and prepared foods (chocolate, smoothies, cakes, cookies and butter). Since there's no standard dosage for marijuana, patients are left to regulate their own intake of medication.

As far as consuming marijuana goes, many patients smoke it, but it has some side effects, besides producing intoxication. Smoke, of course, isn't good for the lungs. However, the effect is nearly immediate, and some studies indicate that marijuana smoke is less toxic than that from cigarettes. Alternatives to smoking include marijuana-laced foods or using a vaporizer. A vaporizer is a device that burns marijuana at a lower temperature than when it's smoked. The vaporizer releases the THC from the plant but produces fewer harmful byproducts. Volcano, one popular model of vaporizer, sells for around $500.

Finally, there are vending machines. The same sort of machines that normally dispense sodas and candy now vend marijuana in a few locations in California, although with strictly controlled access. These machines, operated by medical marijuana dispensaries, require a fingerprint scan and the insertion of an ID card provided by the dispensary. They are monitored by security guards and patients and offer convenient access to the medicine. Operators say they also cut down on expenses, savings that are passed on to the patient.

For related articles on drugs and health, see the next page.

Lots More Information

Related HowStuffWorks Articles

More Great Links

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