CBD and Medication – Interactions

Written by Stefan K.

Interactions between CBD and medications

CBD and drugs: thanks to the growing number of studies in existence, researchers now know many of the effects of the CBD, an active constituent derived from the hemp plant. However, as in the case of research into other known active substances, cannabidiol research has “only” been carried out seriously for about 40 years – ever since it became known that it can be used to treat many diseases, and that it can also be used preventively. Compared with other substances which are known to have a positive influence on the human body, this is certainly a relatively short period. This area of research, which concerns itself with interactions between CBD and other medication, is thus still young, and new discoveries are being made all the time.

It should be noted that the term “interaction” here refers to something akin to that which is meant by the term “drug interaction”. Taking various different active substances or drugs at the same time, a phenomenon referred to as polymedication, can lead to undesired or unexpected pharmacological effects. These can include the strengthening, weakening or even the nullification of the desired effects.

Can interactions between CBD and medication occur?

An indirect interaction between CBD and medication has to do with the breakdown of medication. CBD inhibits specific enzymes (such as CYP2D6 and CYP2C19). These are, however, responsible for the breakdown of many pharmacological agents in the body, and so the interaction may result in the concentration of the medication in the bloodstream remaining unusually high beyond the intended period. Although this can also have positive effects, for example if you want to prolong the duration of the effect of some kind of medication without increasing the dose, it can also increase the risk of harm occurring as the result of an unintended overdose.

  • 1. CBD oil is no panacea but it can certainly help!

    Cannabis and CBD surely are no panaceas but for many people it is a natural remedy that can help with more than 65 different medical conditions. CBD is still quite unexplored but many scientists, doctors and pharmacists shed their prejudices and are interested in the health benefits of cannabidiol. Just always remember: CBD CAN be helpful - but it isn't always.

  • 2) CBD addresses the endocannabinoid system

    Pretty much nobody uses CBD without a reason to do so. CBD is a cannabinoid which is a group of substances that can naturally be found in various plants. These cannabinoids address the endocannabinoid system. Every human has such a system. Via various receptors within this system a number of functions in the body can be regulated, renewed or fixed.

  • 3) Breast milk contains CBD

    A study in 2017 has shown that cannabinoids are not only natural components of cannabis but can also be found in breast milk. Cannabinoids are not only valuable for the neurological growth phases but have many other astonishing health benefits. Without cannabinoids in breast milk newborns would would be less hungry and therefore drink less.

  • 4) CBD is the allrounder amongst cannabinoids

    Every cannabinoid has its own effects. Nonetheless, CBD can be called the allrounder among all cannabinoids. It is not only anti-inflammatory but can also slow down growth of diseased cells. It is also anxiolytic and an immunosuppressant. Therefore, CBD makes for a great dietary supplement and should always be the base. You can add more cannabinoids by choosing full-spectrum CBD products.

  • 5) CBD does not get you stoned

    Cannabidiol is the so-called antagonist of THC. THC means Tetrahydrocannabinol. It is psychoactive and can be found in certain cannabis strains. CBD counteracts with the part of THC that gets consumers 'stoned'. Therefore, the very small amount of THC that can be found in many CBD products is kind of neutralized by the CBD. As a result, CBD products are totally legal and non-psychoactive.

  • 6) WHO rates CBD as harmless

    The World Health Organization WHO published a 27 pages long report where they classify CBD as harmless. The organization states that pure CBD and products that contain less than 0.2% THC are in no way taken into the drug conventions. A reason for that is that CBD is not predicating and there is no danger of abuse. Therefore, CBD is as harmless as water.

  • 7) CBD is not a doping substance and is used in professional sports

    CBD can help reduce inflammations and can support regeneration after physical activities. As a result, many professional athletes (especially in the US) in football, basketball or martial arts use CBD. Many famous athletes also advertise respective compounds. In August 2019 UFC champion Nate Diaz caused a lot of furore when he smoked a CBD joint before a big fight. Nonetheless, it was totally legal since CBD is specifically excluded from the WADA doping list.

  • 8) CBD can be prescribed

    In conventional medicine cannabidiol is not very popular yet. First, doctors need to be informed about CBD in order to shed their prejudices and gather experiences. Nonetheless, even nowadays there are numerous specialists and general practitioners who have trust in the medical potential of cannabis. In some cases doctors also prescribe CBD to their patients.

  • 9) CBD and cannabis can help to cleanse the environment

    Cannabis is a plant that can naturally grow almost everywhere in the world. Additionally, it consumes up to four times as much CO2 as trees. Cannabis is also known for absorbing toxic substances and radioactive chemicals from the soil. Therefore, cannabis is able to cleanse the environment und is good for the earth's climate.

  • 10) CBD exists in all kinds of shapes

    Most people know CBD in the shape of CBD oil. CBD oil is so popular because it is easy to dispense and is well absorbed by the body. Nonetheless, there are numerous other kinds of CBD products such as e-liquids, salves, creams, pastes, flowers, sweets, food or crystals. On CannaTrust.uk you can find many of these products!

By influencing the enzymes CYP3A4, CYP2C9, CYP2C19 and CYP2D6, CBD can cause further interactions to occur. CBD’s inhibition of CYP3A4[1] for example, could alter the effects of antidepressants such as Trazodon. The combined effect of CBD in combination with medication on the enzyme CYP2C19[2] can impair the ability of ticlopidine to inhibit platelet aggregation. If CBD acts on the enzyme CYP2C9[3] this could, among other things, alter the efficacy of torasemide as a loop diuretic. The effects of CBD on CYP2D6[4] could result in the alteration of tetrabenazine’s neuroleptic effects.

These risks also exist when consuming CBD in combination with drugs. Studies have shown that CBD is an antagonist of the psychoactive substance THC (both of which are derived from the hemp plant). For example, taking CBD after smoking THC will reduce or even completely inhibit the effect of the THC. On the other hand, if taken before consuming THC, CBD can even enhance its effects. The same applies to other medication. The reason for this is that THC is broken down by the same enzyme that breaks down other medication, and this enzyme is supressed by CBD. The use of CBD can result in undesirable interactions in the case of the cytotoxic drugs used in chemotherapy. As already mentioned, CBD inhibits the enzyme P450. Amongst other things, it is the reason that the dosage of powerful chemotherapy drugs needs to be so high, because it breaks such medication down. However, if the enzyme can no longer fulfil this task because CBD is present, the dose of cytostatic drugs in the blood increases to a fatal level. 

What medication should not be taken in combination with CBD?

Certain types of medication, when taken over longer periods, can have a harmful effect on the human body due to their inhibition of the P450 enzyme. Medical specialists know that CBD should not be taken at the same time as these, as the danger of such an interaction constitutes a risk which is simply not worth taking.

For those already taking medication, the use of CBD should be monitored very closely. Many doctors advise their patients that, after taking medication, they should wait at least 2h before taking CBD.


Generally speaking, cannabidiol interacts with the following medicines:

  • beta blockers
  • statins
  • anticonvulsants
  • antibiotics
  • anticoagulants
  • anti-inflammatory painkillers
  • steroids
  • antipsychotics
  • antidepressants
  • benzodiazepine

However, this list should not be regarded as being comprehensive! The precise way in which a particular combination will affect the body should be discussed with your doctor. Due to the current state of research experts advise being careful when it comes to using CBD in combination with pharmaceuticals.


  • The above list does not claim to be complete. If you have any doubts, the simultaneous use of CBD and medication should always be discussed with your doctor.

Discussing contraindications of CBD with your doctor

Around 470 million prescriptions are issued in Germany every year. In the case of two percent of these prescriptions, i.e. 9.4 million of them, problems occur as a consequence of the medication patients are prescribed. Many of these problems could be avoided if patients checked package inserts more thoroughly for possible side effects and interactions,  as well as by informing the doctors issuing the prescription of all the substances they were taking, for example.

This knowledge, combined with the patient’s personal history can, even in the case of CBD, be identified as a contraindication on consultation with a doctor. This means that having taken a substance in the past makes it impossible to be given the treatment or therapy which is considered necessary. In such cases, doctors distinguish between absolute and relative contraindications. In the case of absolute contraindication, certain medical measures are rigorously prohibited. In the case of relative contraindication, certain additional treatments and therapies are only approved under strict conditions, once all the risks have been weighed up. 

As described above, CBD interacts with the enzymes involved in the breakdown of active substances. If, therefore, this process of breakdown is not to be disturbed, following consultation with a doctor, the CBD contraindication should be taken very seriously. If such a contraindication is ignored, considerable damage to the health of the patient can result.

Ultimately, in the case of all substances which influence the body, it is always a good idea to consult a trusted specialist before taking them in order to discuss everything thoroughly.

A recent study[5] supports this kind of approach. In this study, the possible toxic effects of CBD on the liver were investigated. The research team found that the mice tested suffered liver damage within 24 hours. Specifically, the CBD drug Epidiolex was administered to the test animals. Whether this negative effect could also occur in humans was not established. Nevertheless, those behind the study advise those who suffer from alcoholism or a predisposition for liver damage to consult with their doctors thoroughly before taking CBD.

[1] https://pgsbox.de/pharma-sensor/CYP3A4?fbclid=IwAR1yG3bIGzSN3yOXHpmdvyiJqNh87r1FFzlWdUn_HprRVi9GvqsVE67Q5oA – 24.09.2019

[2] https://pgsbox.de/pharma-sensor/CYP2C19?fbclid=IwAR00IyL2LAJjR4BHbSGnH-wdVTvq1R4DxXBd6UJ_9BN-CLPuX0IDy3IUKtI – 24.09.2019

[3] https://pgsbox.de/pharma-sensor/CYP2C9?fbclid=IwAR0lo27fr8Sw_cAkvnbbyukZ7lfu66iDndOlnYFf5mUxa3IX8Bu848kIrsQ – 24.09.2019

[4] https://pgsbox.de/pharma-sensor/CYP2D6?fbclid=IwAR1mURNkjYRVsPQ65mMO6ZrYxklvDr3e-WlhqLk_GbW8XNdN3AYOkFosUMs – 24.09.2019

[5] https://www.mdpi.com/1420-3049/24/9/1694 – 27.07.2019

Taking products containing cannabinoids may result in interactions with various medications. If you are already taking medication, the use of CBD and other cannabinoids should be discussed with your doctor beforehand.

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About the author

Stefan K.

Stefan K.

Stefan is not only a valuable part of the CannaTrust magazine but also convinces with his sound knowledge about the effects of cannabinoids. As an author in Austria he gathered valuable experiences when writing for 'Stadtblatt Salzburg'. He got in contact with cannabis through several positive media reports. Nowadays he writes about everything around the most popular cannabinoid these days: CBD.