Ask Dr. Leigh: Why is medical marijuana federally illegal? What is the history that led up to that?

(Getty Images / Hero Images)

Using cannabis can have a big impact on your physical and mental health—for better, and sometimes for worse. That’s why it’s important to consult a healthcare provider before experimenting.

Here at GreenState, cannabis clinician Dr. Leigh Vinocur is here to answer your questions on healthy living with cannabis.

Editor’s Note: The answer to this question is meant to supplement, not replace, advice, diagnoses, and treatment from a healthcare provider.  Always consult a medical professional when using cannabis for medicinal purposes, and do not disregard the advice of your healthcare provider because of anything you may read in this article. 

Q: Why is medical marijuana federally illegal? What is the history that led up to that?

A: Cannabis has a long, complicated, and conflicting history in US politics. Historically it has been used as a food, a fiber, and a medicine for thousands of years in many different countries and cultures. In the US it has only been prohibited for the last 84 years, starting with the Marijuana Tax Act of 1937. Prior to that, cannabis was part of the US Pharmacopeia and had been frequently used for analgesia, anti-inflammatory and anti-spasmodic indications. In fact, US pharmaceutical companies such as Eli Lilly and Bristol-Meyers Squibb created commercial tinctures of cannabis.

The factors that led to cannabis being regulated differently and prohibited in the early decades of the 20th century were fueled by politics, greed, and racism, not science.

Harry Anslinger was the appointed commissioner of the newly founded Federal Bureau of Narcotics just after alcohol prohibition had failed. He drafted the Marihuana Tax Act. This law levied taxes on hemp and cannabis products and neither physicians nor pharmacists were exempt. Additionally, he used the Mexican name for cannabis, marihuana, an unfamiliar term to the medical community, with racist implications.

The AMA opposed this legislation. In a statement to the Committee of Ways and Means in the House of Representatives on May 4th, 1937, legal counsel for the AMA Dr. William C. Woodward, said, “There is nothing in the medicinal use of cannabis that has any relation to cannabis addiction. I use the word cannabis in preference to the word marihuana because cannabis is the correct term for describing the plant and its products. The term marihuana is a mongrel word that crept into this country over the Mexican border and has no general meaning, except it related to the use of cannabis preparations for smoking. It is not recognized in medicine.”

Woodward goes on, “To say, however, as has been proposed here, that the use of the drug should be prevented by a prohibitive tax, loses sight of the fact that future investigation may show that there are substantial medicinal uses for cannabis.”

Titans of the industry, such as William Randolph Hearst used his newspapers as a platform to spread racist propaganda about Mexicans and African Americans, falsely describing the incitement of violence from smoking marijuana.

This new regulation in the early 20th century, the Marihuana Tax Act of 1937  levied taxes on businesses, such as physicians and pharmacists, making its penalties financial in nature. This law didn’t really prohibit the use of cannabis, but it became too expensive for doctors to prescribe or pharmacists to compound, so it fell out of favor.  And in 1942 cannabis tincture was finally dropped in the 12th edition of the US Pharmacopeia.

But there was still controversy and dissent with politicians and cannabis. In 1944 the New York Academy of Medicine published a report commissioned by their mayor at the time Fiorella LaGuardia called the LaGuardia Report that found cannabis did not lead to insanity or addiction to other drugs, nor did it lead to the incitement of violence or sex crimes. This positive report pushed Anslinger to persuade the government to move beyond financial penalties mainly affecting businesses to penalizing and prosecuting the users of cannabis. Ushering in a new era in government whereby it attempted to use the criminal justice system as a deterrent.

In the late 50s, Eisenhower appointed members of his cabinet to create an Interdepartmental Committee on Narcotics. Their 1956 report, known as the Eisenhower Report, focused on the harms related to cannabis/marijuana. It outlined 14 recommendations, the 10th of which pushed for harsher penalties related to marijuana. It called for increased criminalization, with increased maximum mandatory sentencing, even for first-time marijuana users.

In the early 60s President Kennedy’s Advisory Commission on Narcotic and Drug Abuse pushed back on the Eisenhower report arguing that the social and financial cost of criminalization of drug users was too great. After Kennedy’s assassination, Johnson had the foresight to see that drug addiction is a disease, not a crime, and he too saw the futility in criminalizing users. In Johnson’s 1966 address to Congress, he said, “Our continued insistence on treating drug addicts, once apprehended, as criminals, is neither humane nor effective. It has neither curtailed addiction nor prevented crime.”

Additionally, another signal that the government acknowledged that drug addiction was a public health issue was evident when jurisdiction for some of the drug policies was moved away from law enforcement and into the department of Health Education and Welfare (HEW.) This was formalized in 1965 with the passage of the Drug Abuse Control Amendment Act, which also expanded the powers of the Secretary of HEW.

Additionally, in the 60s and 70s, cannabis use increased with middle-class college youth, locking up “America’s brightest” for minor possession offenses became unpalatable. As the number of arrests for possession charges started to climb, congress enacted the Comprehensive Drug Abuse and Control Act, in October of 1970.  It separated marijuana from other drugs, lowering the maximum penalty for possession of an ounce or less to 1 year in jail and a $5000 fine. But more importantly, there was no longer mandatory sentencing. Judges now had the discretion of choosing probation with a conditional discharge. This meant if there were no further offenses by the defendant during the probation period the charges could be dropped and the arrest record then expunged, thereby removing some of the stigma around possessing small amounts of cannabis for personal use. However, not all communities were treated equally. To this day, poorer communities of color have been disproportionately targeted and suffered the most when it comes to the criminalization of cannabis.

Even into the 70s this notion of drug addiction as a public health problem was set back as the next administration under Nixon declared “War on Drugs.” Nixon appointed his old friend former Pennsylvania governor, Raymond Schaffer to chair a committee called the National Commission on Marihuana and Drug Abuse. They published their report titled, Marihuana: A Signal of Misunderstanding. And it came to much of the same conclusions of the LaGuardia report—mainly that it was not a danger to society, comparing it to that of alcohol. It also recommended using social measures to discourage its use and calling for decriminalization. It was said Nixon was not happy with this report and because marijuana use was associated with the counterculture and its war and government protests, therefore the  White House ignored its recommendations completely.

And just as Dr. Woodward had feared back in 1937, the final blow given to medicinal was dealt by the Controlled Substance Act of 1970, listing cannabis as a Schedule 1 drug, which is a “drug having a high potential for abuse, no current accepted medical use in treatment in the US, and lack of accepted safety” thereby thwarting much meaningful research, even up to this day.


Got cannabis questions? Ask Doctor Leigh. Send your questions to GreenState’s Assistant Editor Elissa Esher at and keep an eye out for new answers from Dr. Leigh Vinocur every month.

Dr. Leigh Vinocur is a board-certified emergency physician who also has a cannabis consulting practice for patients and industry. She is a member of the Society of Cannabis Clinicians and a graduate of the inaugural class, with the first Master of Science in the country in Medical Cannabis Science and Therapeutics from the University of Maryland School of Pharmacy.

The response to this question was not written or edited by Hearst. The authors are solely responsible for the content.

Leigh Vinocur, MD