CBD and Other Drugs: Proceed with Caution - Harvard Health (2023)

Products containing cannabidiol (CBD)they seem to be in fashion these days, promising relief from a wide range of ailments, from insomnia and hot flashes to chronic pain and seizures. Some of these claims have merit for them, thoughsome of them are just hype. But it doesn't hurt to try, right? Well, not so fast. CBD is a biologically active compound and as such can have unintended consequences. This includes the known side effects of CBD, but also unintended interactions with dietary supplements, herbal products, and over-the-counter (OTC) and prescription medications.

(Video) Recreational Marijuana and CBD: What doctors don’t know

Duplication of side effects

While generally considered safe, CBD can cause drowsiness, dizziness, nausea, diarrhea, dry mouth and, in rare cases, liver damage. Taking CBD with other medications that have similar side effects may increase your risk of unwanted symptoms or toxicity. In other words, taking CBD at the same time as OTC or prescription drugs and substances that cause drowsiness such as opioids, benzodiazepines (such as Xanax or Ativan), antipsychotics, antidepressants, antihistamines (such as Benadryl) or alcohol can lead to increased drowsiness. , fatigue and possible accidental falls and accidents while driving. Increased sedation and fatigue can also occur with the use of certain herbal supplements, such as coffee, melatonin, and St. John's wort. Taking CBD with stimulants (like Adderall) can lead to decreased appetite, while taking it with the diabetes drug metformin or certain heartburn medications (like Prilosec) can increase your risk of diarrhea.

(Video) Recreational Marijuana and CBD: Public Attitudes, Science, and the Law

CBD can alter the effects of other medications

Many drugs are broken down by enzymes in the liver, and CBD can compete with or interfere with these enzymes, leading to either too much or too little of the drug in the body, which is called altered concentration. An altered concentration may cause the medicine not to work or increase the risk of side effects. These drug interactions are often difficult to predict, but they can cause unpleasant and sometimes serious problems.

(Video) Recreational Marijuana and CBD: Four Takeaways

Penn State College of Medicine researchersevaluated the existing informationin five prescription cannabinoid drugs CBD and delta-9-tetrahydrocannabinol (THC): anti-nausea drugs used during cancer treatment (Marinol, Syndros, Cesamet); a drug used primarily for muscle spasms in multiple sclerosis (Sativex, which is currently not available in the US but is available in other countries); and an anti-seizure drug (Epidiolex). In all, the researchers identified 139 drugs that can be affected by cannabinoids. This list is further reduced to57 medications, for which the altered concentration can be dangerous. The list contains a variety of drugs, from heart drugs to antibiotics, although CBD-only products may not affect all drugs on the list (some are only affected by THC). Potentially serious drug interactions with CBD included

(Video) DOES CBD REALLY DO ANYTHING? Real Doctor Explains Everything You Need Know About Cannabidiol CBD Oil

  • the common anticoagulant, warfarin
  • heart rhythm medication amiodarone
  • thyroid medication, levothyroxine
  • several seizure medications, including clobazam, lamotrigine, and valproate.

The researchers further cautioned that while the list can be used as a starting point to identify potential drug interactions with cannabis or CBD oil, plant-based cannabinoid products can deliver very different concentrations of cannabinoids (as opposed to approved prescription cannabinoid drugs). by the FDA mentioned above). and may contain many other compounds that may increase the risk of unintended drug interactions.

(Video) CBD (That’s Cannabidiol) and the Growing Epidemic of Teen Vaping, A. Eden Evins, MD, MPH

Does the form of CBD matter?

Absolutely. Inhaled CBD enters the blood faster, reaching a high concentration within 30 minutes and increasing the risk of acute side effects. Edibles take longer to absorb and are less likely to produce a high peak concentration, although they can eventually reach levels high enough to cause a problem or interact with other drugs. Topical formulations such as creams and lotions may not be absorbed and may enter the bloodstream in sufficient amounts to interact with other medications, although there is very little information on how much CBD ends up in the bloodstream. This is all further complicated by the fact that none of these products are regulated or tested for purity, concentration or safety.

(Video) Medical Cannabis education with Dr Peter Grinspoon, MGH, Harvard Medical School

Bottom Line: Talk to your doctor or pharmacist if using or considering CBD

CBD has the potential to interact with many other products, including over-the-counter, herbal, and prescription drugs. Some medications should never be taken with CBD; the use of other medications may need to be modified or reduced to avoid serious problems. The consequences of drug interactions also depend on many other factors, including the dose of CBD, the dose of the other drug, and the person's underlying medical condition.older adultsare more susceptible to drug interactions because they often take multiple medications and because of age-related physiological changes that affect how our bodies process drugs.

(Video) Does CBD really work?

People considering or taking CBD products should always mention their use to their doctor, especially if they are taking other medications or have other health conditions such as liver disease, kidney disease, epilepsy, heart problems, a weakened immune system, or use of medications that may weaken the immune system (such as cancer drugs). A pharmacist is a great resource to help you learn more about a possible interaction with a dietary supplement, herbal product (many of which have their own drug interactions), or over-the-counter or prescription medications. Don't assume that just because something is natural it's safe and there's no harm in trying it. It might as well.

(Video) What's all the buzz about CBD oil? | Just The FAQs


What is the Harvard warning about CBD? ›

CBD can alter the effects of other drugs

The altered concentration, in turn, may lead to the medication not working, or an increased risk of side effects. Such drug interactions are usually hard to predict but can cause unpleasant and sometimes serious problems.

What supplements should not be taken with CBD? ›

CBD might cause sleepiness and slowed breathing. Taking it along with other supplements with similar effects might cause too much sleepiness and/or slowed breathing in some people. Examples of supplements with this effect include hops, kava, L-tryptophan, melatonin, and valerian.

Will CBD gummies show up on a DOT drug test? ›

It is important for all employers and safety-sensitive employees to know: The Department of Transportation requires testing for marijuana and not CBD. The labeling of many CBD products may be misleading because the products could contain higher levels of THC than what the product label states.

Can I take CBD and antidepressants? ›

Taking both medications at the same time could increase the likelihood and severity of side effects. The key point to stress here is you shouldn't use CBD and antidepressants together before consulting a medical professional.

Are there any dangers of CBD? ›

CBD use also carries some risks. Though it's often well-tolerated, CBD can cause side effects, such as dry mouth, diarrhea, reduced appetite, drowsiness and fatigue. CBD can also interact with other medications you're taking, such as blood thinners.

Are there any health risks with CBD? ›

Potential risks and harms associated with CBD use include adverse drug interactions, liver toxicity, and reproductive and developmental effects.

When should you avoid CBD? ›

Absolute contraindications to CBD are allergies to cannabidiol or sesame oil. At first signs of skin, cutaneous irritation, or anaphylactic reaction, the patient should stop using CBD.

Can I take CBD with ibuprofen? ›

Yes, you can take ibuprofen and CBD oil together. However, it is important to note that ibuprofen can increase the effects of CBD, so it is best to start with a lower dose of CBD oil when taking ibuprofen.

Can you take B12 and CBD? ›

Interactions between your drugs. No interactions were found between cannabidiol and Vitamin B12.

What is the FDA warning about CBD? ›

The FDA has sent warning letters in the past to companies illegally selling CBD products that claimed to prevent, diagnose, treat, or cure serious diseases, such as cancer.

What is the p65 warning on CBD? ›

Although under federal law CBD products are allowed to contain up to 0.3 percent THC, or Δ9-Tetrahydrocannabinol, no safe harbor level of exposure to THC has been established under Prop. 65. That means private enforcers can argue that any detectable amount can subject a product to the Prop. 65 warning requirement.

What does the FDA say about CBD? ›

The FDA now says CBD products cannot be considered dietary supplements or food additives, citing the findings from a working group review of studies, scientific literature and other information submitted by the public.

What is an unhealthy amount of CBD? ›

However, according to a 2011 study, published in Current Drug Safety, the “toxic” dose of CBD falls somewhere around 20,000 mg of CBD, taken almost all at once. To understand this, it's important to note that the suggested starting dose for most conditions is somewhere around 5-20 mg per day.


1. Medical Cannabis education with Dr Peter Grinspoon, MGH, Harvard Medical School
(Global Health Catalyst)
2. Does CBD really work?
(Dark Science)
3. What's all the buzz about CBD oil? | Just The FAQs
4. Harvard study casts doubt over medical marijuana treating anxiety, depression
(23 ABC News | KERO)
5. The Oral Health Benefits of CBD
(Joseph R Nemeth DDS)
6. Psychedelic Medicine: From Tradition to Science
(Harvard Medical School)


Top Articles
Latest Posts
Article information

Author: Gov. Deandrea McKenzie

Last Updated: 08/09/2023

Views: 6722

Rating: 4.6 / 5 (66 voted)

Reviews: 81% of readers found this page helpful

Author information

Name: Gov. Deandrea McKenzie

Birthday: 2001-01-17

Address: Suite 769 2454 Marsha Coves, Debbieton, MS 95002

Phone: +813077629322

Job: Real-Estate Executive

Hobby: Archery, Metal detecting, Kitesurfing, Genealogy, Kitesurfing, Calligraphy, Roller skating

Introduction: My name is Gov. Deandrea McKenzie, I am a spotless, clean, glamorous, sparkling, adventurous, nice, brainy person who loves writing and wants to share my knowledge and understanding with you.