CBD oil and medicines: antidepressants, blood thinners and more

Can you take CBD oil with medicines? That depends on the medicine, and only your doctor or pharmacist can assess that for you. CBD is a food supplement, but that does not mean it has no influence on other substances you use. The Dutch Medicines Evaluation Board (CBG) asks people to take care when combining herbal preparations with cannabis and medicines, and names anti-epileptics and antidepressants in particular.

Below you can read, per group of medicines, what is known, with the source included. We cannot give you a safe combination or a safe amount. This article helps you prepare the conversation with your doctor or pharmacist.

What is an interaction?

An interaction arises when two substances influence each other in your body. A medicine can then work less well, work more strongly than intended, or side effects can occur.

With CBD this mainly happens in the liver. CBD is broken down there by the same enzymes that also process many medicines, the cytochrome P450 system. Researchers at Harvard Medical School write that CBD may compete for these enzymes or interfere with them. As a result, too much or too little of a medicine can end up in your body.

CBD oil and antidepressants

The CBG names antidepressants as one of the groups to be careful with when it comes to cannabis. A study from 2021 makes this concrete. Anderson and colleagues examined in the laboratory how CBD affects the breakdown of four commonly used antidepressants. CBD had little effect on sertraline, fluoxetine and mirtazapine. It did clearly inhibit the breakdown of citalopram and escitalopram.

The researchers then looked at six patients who took citalopram or escitalopram and added CBD. In them, the amount of citalopram in the blood rose. Whether that also led to more side effects, the study could not establish. The researchers ask doctors to be alert to it.

In addition, CBD and antidepressants that make you drowsy can reinforce each other. Harvard lists antidepressants among the substances that, together with CBD, can lead to more sleepiness and fatigue.

If you take an antidepressant, do not start with CBD without talking to your doctor or pharmacist. And never stop your antidepressant on your own.

CBD oil and blood thinners

Harvard lists the blood thinner warfarin among the potentially serious interactions with CBD. If CBD causes more of a blood thinner to stay in your blood, the chance of bleeding increases.

If you take a blood thinner, whichever one, talk to your doctor, your pharmacist or your anticoagulation clinic before you start using CBD. Watch for signs of bleeding, such as unexplained bruising, more frequent nosebleeds, small cuts that keep bleeding or bleeding gums. If you notice any of these, contact your doctor straight away.

CBD and melatonin

Melatonin is a hormone your body makes itself when it gets dark. It plays a role in your sleep-wake rhythm. Products with a daily dose below 0.3 mg are in principle not regarded as a medicine by the Dutch Health and Youth Care Inspectorate (IGJ). From 0.3 mg, melatonin can count as a medicine. We do not sell melatonin.

Hardly any research has been done on CBD and melatonin together. Harvard does list melatonin among the supplements that, together with CBD, can lead to more sleepiness and fatigue. If you take melatonin, especially on prescription or at a higher dose, talk to your GP or pharmacist before you add CBD. You can read more about CBD, CBN and sleep in CBD oil and sleep: what does the research say?

Other medicines that need extra attention

Heart rhythm and thyroid medication

Among the potentially serious interactions with CBD, Harvard also lists the heart rhythm medicine amiodarone and the thyroid medicine levothyroxine. If you take one of these, discuss CBD with your doctor first.

Sleeping pills and sedatives

Harvard writes that CBD combined with substances that make you drowsy, such as benzodiazepines, antihistamines or alcohol, can lead to more sleepiness, fatigue and possibly falls or accidents while driving. Jellinek says the same about alcohol, sleeping pills and sedatives: CBD oil can strengthen their effect, so take extra care in traffic.

Epilepsy medication

The CBG names anti-epileptics, and Harvard mentions clobazam, lamotrigine and valproate. If you take anti-epileptic medication, never start with CBD without talking to your neurologist.

How to discuss CBD with your doctor or pharmacist

Tell your GP and your pharmacist that you use CBD or want to start, even though it is a food supplement. Name the product, the percentage and how often you take it, or bring the packaging. Only then can your doctor or pharmacist assess the combination with your medicines.

Do not start with CBD on your own alongside a medicine from one of the groups above. If after starting you notice something you cannot explain, such as unusual tiredness, dizziness or a medicine that seems to work differently, contact your doctor. Never simply stop taking your medicines without medical advice.

If you want to know which side effects of CBD itself are known, read does CBD oil have side effects? And if you first want to understand which types of CBD oil there are, which CBD oil suits me? will help.

Frequently asked questions about CBD and medicines

Can you take CBD oil with medicines?

That depends on the medicine, and only your doctor or pharmacist can assess that for you. CBD is broken down in the liver by the same enzymes that also process many medicines. As a result, a medicine can work less or more strongly, or side effects can occur. So always check first.

Can you take CBD oil with antidepressants?

Talk to your doctor or pharmacist first. The CBG names antidepressants as a group to be careful with. In a 2021 study, the amount of citalopram in the blood rose in people who added CBD. Never stop your antidepressant on your own.

Can you take CBD oil with blood thinners?

Talk to your doctor, your pharmacist or your anticoagulation clinic first. Harvard lists the blood thinner warfarin among the potentially serious interactions with CBD, because more of the medicine can stay in your blood. Watch for signs of bleeding, such as unexplained bruising.

Does CBD with melatonin cause side effects?

Hardly any research has been done on that combination. Harvard lists melatonin among the supplements that, together with CBD, can lead to more sleepiness and fatigue. If you take melatonin, especially on prescription, talk to your GP or pharmacist. Also read CBD oil and sleep.

What should not be combined with CBD oil?

Extra attention is needed with blood thinners such as warfarin, antidepressants, the heart rhythm medicine amiodarone, the thyroid medicine levothyroxine, epilepsy medication, and sleeping pills and sedatives. Alcohol and melatonin can also lead to extra drowsiness together with CBD. If you take something from this list, talk to your doctor or pharmacist first.

How much CBD can you take alongside medicines?

We cannot give a number for that. Whether and how much CBD is possible alongside your medicines depends on the medicine and on you, and your doctor or pharmacist assesses that. Bring the packaging of your CBD to that conversation.

Should I tell my doctor that I use CBD?

Yes. Even though CBD is a food supplement, your doctor and pharmacist can only assess an interaction if they know everything you use. Name the product, the percentage and how often you take it.

Important information before you combine CBD and medicines

CBD is a food supplement and not a medicine. We do not give medical advice, and this article does not replace the conversation with your doctor or pharmacist. If you are pregnant or breastfeeding, do not use CBD. Never simply stop taking medicines without medical advice.

At Dutch Balance we work with brands that have their products tested by external laboratories for purity and content. The reports are available on request.

CBD oil and medicines: watch out for these interactions