To make sense of it all, first you need to understand the cannabis plant, which is where it all starts. Cannabis is a species of plant that has over 100 different chemical constituents called cannabinoids and the two main cannabinoids are tetrahydrocannabinol (THC) and cannabidiol (CBD),” says Ryan Vandrey, Ph.D. associate professor Behavioral Pharmacology Research Unit at Johns Hopkins University School of Medicine.

Though they’re often used interchangeably, cannabis and marijuana are not the same thing. Cannabis is like an umbrella and refers to all products derived from the cannabis plant. Marijuana is a more specific term. It refers to parts of the cannabis plant containing high levels of THC, the substance that drives the psychoactive effects that make you feel high. There are three strains of cannabis: sativa, indica, and a hybrid of the two.

Now that you know the basics, let’s get to the root of it all so you have an even better understanding of the landscape.

What Is Cannabis?

There’s a lot of confusion surrounding the legality of cannabis. In general, cannabis that has 0.3% THC or less is considered legal (this is known as hemp), cannabis with 0.3% THC or greater (also called marijuana) is illegal depending on the state in which you live.

“Both hemp and marijuana belong to the same genus and species of the Cannabis Sativa plant,” says Mahmoud A. ElSohly, Ph.D., professor of pharmaceutics at the National Center for Natural Products Research a division of The Research Institute of Pharmaceutical Sciences The University of Mississippi.

“The chemical profiles of both varieties are qualitatively similar, but quantitatively different. The most important difference is in the THC and CBD content, with THC being the predominant cannabinoid in marijuana and with CBD the most predominant cannabinoid in hemp,” Dr. ElSohly says.

Many Different Strains of Cannabis horizontal business infographic illustration about cannabis as herbal alternative medicine and chemical therapy, healthcare and medical science vector.

(Image: iStock)

What Is Marijuana?

The word “marijuana” refers to cannabis containing more than 0.3% THC. Marijuana is still classified as a Schedule 1 drug, which means that at the federal level, any marijuana-derived product is considered illegal.

Yes, we know what you’re thinking. States themselves have the ability to legalize both medical and recreational marijuana. That’s why there are currently, 33 states that have legalized medical marijuana and 11 states and Washington, D.C. have legalized marijuana for recreational use for adults over 21.

Though you may live in a state that legalizes marijuana, you can’t just walk into a CVS and fill a prescription. Just like any prescription medication, you’ll need a reason for your doctor to recommend medical cannabis. And each state has specific or “qualifying” conditions that can be legally treated with cannabis. Some approved medical conditions include Crohn’s disease, cancer, pain, glaucoma, HIV/AIDS, PTSD, fibromyalgia, and multiple sclerosis.

You’ll also need a medical cannabis card, which you need to take with you to a marijuana dispensary—if you live in a state where it’s legal. Even in legal states, you can’t go to your regular pharmacy for medical marijuana.

Hemp vs Marijuana vertical infographic, healthcare and medical illustration about cannabis

(Image: iStock)

What Is THC?

THC is a cannabinoid, a specific chemical entity found naturally in the cannabis plant that is responsible for the psychoactive effects that make you feel high. It works by binding to receptors in the brain and central nervous system (known as cannabinoid receptors) to produce intoxicating effects.

THC is also what gives cannabis therapeutic effects. “It can help ease the pain and nausea associated with chemotherapy and it can help give you an appetite to eat,” Dr. Vandrey says. Cannabis with high levels of THC can be consumed in a variety of different ways by smoking, via an oil tincture placed under the tongue, or ingested as an oil in a capsule or in food.

What Is CBD?

CBD is a single chemical entity molecule and the second main cannabinoid found in cannabis. Unlike THC, CBD is not psychoactive, i.e. it can’t get you high. CBD can come from both hemp and marijuana however, only CBD derived from hemp is legal (because it’s under 0.3% THC).

Marijuana-derived CBD is illegal and is still classified as a controlled substance regardless of its percentage of THC. If that seems kind of illogical to you, you’re right. The reason is less about the CDB itself and more about how it came into existence.

While CBD seems to be everywhere and touted as a cure for just about everything (which is why you see it in on labels from lotions and balms to oils and tinctures), the only FDA-approved usage is a medication called Epidiolex, which treats the seizures associated with two rare and severe types epilepsy, Lennox-Gastaut syndrome and Dravet syndrome, in patients two years of age and older.

Despite the limited approved use, many people swear CBD helps relieve a slew of different conditions, including anxiety, pain, insomnia, as well as the side effects from chemotherapy. “Pure CBD is non-intoxicating and non-addictive and it has no abuse liability,” says Massachusetts General Hospital internist Peter Grinspoon, M.D. an instructor in medicine at Harvard Medical School and board member of the advocacy group Doctors For Cannabis Regulation.

“It doesn’t directly stimulate the cannabinoid receptors in the brain and nervous system the way THC does, so it doesn’t cause a high, but it does affect a lot of the other receptors and can help with sleep, insomnia, and pain,” he says.

The problem is since the FDA doesn’t regulate CBD, it’s hard to know exactly what you’re getting and whether the sample is pure. “There are a lot of variants in the composition of products sold as CBD, including the constitution, the formulation, and how it’s intended to be used—topically applied, inhaled, swallowed. And all of those different variations can produce different outcomes,” Dr. Vandrey says.

“While it’s relatively safe, there’s accumulating evidence that it can have really significant drug interactions with certain other medications,” he says. The bottom line is, if you have any health conditions, before you use CBD, talk to your doctor, Dr. Vandrey says

What Is Hemp?

Hemp is a term used to categorize cannabis containing 0.3% THC concentration or less. Hemp is not something new. It has been used for thousands of years to make things like rope, clothing, building materials, paper, and even food. There was no controversy around it. That is until 1937 when it became illegal along with marijuana. (The two plants looked so similar, federal agents couldn’t tell them apart, so both just became illegal).

In 2018 The Agriculture Improvement Act  (aka The Farm Bill) legalized hemp again in all 50 states. Today you can find hemp everything from pasta and iced tea to personal care products, nutritional supplements, and clothes.

Last Updated: Jul 1, 2020