CBD vs THC: What the Difference Means for Patients

CBD and THC are the two cannabinoids people hear about most. They come from the same plant, but they act differently in the body, and the difference matters for your safety and your daily life. This guide explains the basics so you can have a better conversation with your clinician.

What CBD and THC Are

Cannabinoids are compounds found in the cannabis plant. THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol) are the two main ones. Many products contain both, in different ratios, and some contain mostly one or the other.

The Key Difference: Intoxication

THC is intoxicating. It is the main substance responsible for the "high" associated with cannabis. It can affect your mood, perception, coordination, reaction time, and memory.

CBD is not intoxicating. It does not cause a high. But "not intoxicating" is not the same as "no effects." CBD can cause sleepiness or reduced alertness, changes in mood, lower appetite, and stomach upset such as diarrhea. It has also been linked with liver injury and with interactions with other medicines.

FDA-Approved Cannabinoid Medicines

A few cannabinoid medicines have been reviewed and approved by the FDA for specific uses:

• Epidiolex contains a purified form of CBD. It is approved for seizures linked to certain rare conditions: Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex.
• Dronabinol (sold as Marinol and Syndros) is a synthetic form of THC. It is approved for specific uses, including loss of appetite with weight loss in people with AIDS.

These approvals apply to those specific products and uses. They do not mean that other CBD or THC products are proven safe or effective for other conditions.

Drug Interactions

Both CBD and THC can interact with other medicines. They can change how your body processes some drugs, which may make those drugs stronger or weaker. Medicines worth asking about include blood thinners, some seizure medicines, sedatives and sleep aids, opioids, and some antidepressants. Alcohol can add to the effects of THC.

Always tell your clinician about every medicine and supplement you take, including over-the-counter CBD.

Driving and Safety-Sensitive Work

THC can impair your ability to drive, and cannabis use has been linked to a higher risk of car crashes. Don't drive or operate machinery while you feel any effects. If you work in a safety-sensitive job or are subject to drug testing, talk with your clinician first. Products marketed as CBD can still contain THC, which could affect a drug test.

Pregnancy and Breastfeeding

The FDA advises against using cannabis products, including CBD, during pregnancy or while breastfeeding. If you are pregnant, planning a pregnancy, or breastfeeding, tell your clinician before using any cannabis product.

Other Health Considerations

THC may not be a good fit if you have a history of certain mental health conditions, heart problems, or substance use concerns. Some people also develop problem use over time. Your clinician will ask about these things during your evaluation because they affect your safety.

"Start Low, Go Slow"

You may hear the phrase "start low, go slow." It describes an approach some clinicians use to limit side effects when a patient begins a new product. Whether and how it applies to you, including which product, what ratio of CBD to THC, and what dose, is something to work out with your clinician rather than on your own.

How This Relates to State Medical Programs

North Dakota and Minnesota each regulate which medical cannabis products registered patients may buy and where. A medical card is issued under your state's law. Federal law and other states' laws may differ, so check before traveling.

Next Steps

If you are thinking about medical cannabis and want to talk through CBD, THC, and your other medicines with a clinician, see our medical cannabis evaluations or book a visit. Before you come in, read what to bring to your evaluation. Minnesota residents can also see the current Minnesota registration steps.