Pharmaceutical drugs have become omnipresent in developed countries. Take a look around: the opioid epidemic caused by prescription opioid painkillers is an everyday headline in the US. The UK National Health Service (NHS) recently prescribed a record number of antidepressants. And the contamination of a blood pressure medicine batch can have global implications.
For millions of people, medicine is crucial to manage chronic pain, mental health conditions and blood pressure. Areas where CBD medical research have had exciting breakthroughs.
This raises an important question: what happens when you want to bring CBD and its health benefits into the equation? What CBD-drug interactions should you be aware of? Keep on reading as we navigate the crossroad where CBD and other medicinal drugs meet on the human body.


According to The Pharmacology Education Project, drug interaction “occurs when the administration of one drug alters the clinical effects of another”, disrupting its absorption, distribution, metabolism or excretion capacities inside the body.The effects, as pointed by the US Food and Drug Administration (FDA), can have three potential outcomes:

1. Prevent a medicine from working the way it should.

A very problematic scenario. Drugs and dosages work in very specific ways, but interactions can either enhance or reduce their effect. The result then is either a dangerous increase of the drug in the system or an ineffective treatment.

2. Cause a side effect from medicine to get worse or better.

A fascinating matter, meaning that the effects have the potential to be both positive and negative. Medicines are all about finding equilibrium. And interactions can either brake or or make it.

3. Cause a new side effect.

Think an adverse reaction, which prompts treatments to derail, sometimes in unknown directions.

Now, when it comes to hemp oil, the epicenter for CBD-drug interactions is in the liver. There is where a fundamental family of liver enzymes known as cytochrome P450 do their work. And here is when it all gets exciting.


The pivotal importance of this enzyme family is easy to assess. As the folks at Project CBD note, “this key enzyme group metabolizes most of the drugs we consume, including more than 60% of marketed meds”.

Cannabidiol, of course, is no stranger to this pathway. Along with more than half of medical drugs, cytochrome P450 enzymes also metabolize CBD. And CBD, research has shown, is a potent inhibitor for most of those enzymes.

That means that CBD can affect their capacity to process other medications. Which, by displacing chemical competitors, cause what we already define as drug-drug interactions.


Drugs are designed to enter and leave the body on very specific timeframes. That’s why dosages exist. But when a drug interaction occurs, that doesn’t always happen.

In the presence of an inhibitor like CBD, drugs have to compete to be broken down. And when competition takes place some drugs go first, while others have to wait or leave.

The body can’t metabolize them all in time, at the same time. So when they leave too quickly, medications are less effective. And when they stay for too long, they accumulate in the system, elevating overdose risk.
But those dangers are one side of the story. Besides the potential adverse effects, CBD-drug interactions can also have a beneficial impact.

How? By enhancing the drug effect. Some drugs come with aggressive side effects, so the less you have to take, the better. By enhancing drug potency, dosages can be lowered and side effects reduced.

The key is maintaining a balance, so the drug can still be effective while side effects decrease. In this scenario, hemp oil emerges as an excellent alternative for adjunct therapy. Let’s see some examples.

CBD and Blood Pressure Medication

Cannabidiol has shown some promising potential for the cardiovascular system. Data suggest that a single dose can reduce resting blood pressure. It can also be a vasodilator, allowing for greater blood flow. And some studies have noted that it reduces cardiovascular response to anxiety and stress situations.

As for drug interactions, links between CBD and anticoagulants have also been studied. This case report involves warfarin, the most commonly used oral anticoagulant worldwide.

This case report involves warfarin, the most commonly used oral anticoagulant worldwide. And as we mentioned before, the benefits come from enhancing the drug effect. In this particular case, CBD rapidly increased warfarin levels. As a result, warfarin dose was reduced 30%, cutting back on side effects like the threat of severe bleeding.


Do a “hemp oil benefits” Google search and its anti-inflammatory properties will surely pop up. There is plenty of evidence on the potential of CBD for anti-inflammatory and chronic pain treatments.  Even to the point where athletes and sports leagues are starting to embrace the benefits.

And what’s the deal with CBD and Non-Steroidal Anti Inflammatory Drugs (NSAIDs)? When it comes to interactions, it’s similar to that of blood pressure medication.
Think drugs like ibuprofen, aspirin and naproxen. When taken at the same time as CBD, they can stay in the body for a longer time, increasing drug concentration.

That can have potential adverse affects. But as you already know, it can also be beneficial for cutting back on dosage, and potentiating its anti-inflammatory and painkilling effects.

CBD and Antidepressants

In both human and animal studies, CBD has shown promise when it comes to reducing anxiety and depression. This study provided evidence of its benefits in the reduction of anxiety for public speaking. And this one documented its effectiveness for treating anxiety and insomnia in children with posttraumatic stress disorder (PTSD).

As for CBD-antidepressant interaction, CBD can unlock both positive and negative effects. This article points out benzadiapedines, for which CBD products can increase sedation. But it can also improve mood on bipolar disorder when taken with mood stabilizers.

Go Check you medicines and their possible interactions

So, which drugs should not be taken with CBD? Cannabidiol already appears on some online interaction checkers. And there are a couple of lists you should also check out before taking CBD if you’re already using other medications.

This list can give you insight into four categories: nedication that may increase CBD levels,  medications that may decrease CBD levels, medicines that can have their levels increased by CBD, and medicine that can decrease their levels when used along CBD.

Now, if you want to see a more specific list, we recommend that you check out the Drug Interactions Flockhart Table. It’s a fantastic compilation by the Indiana University School of Medicine, in which you can find drugs metabolized by the cytochrome P450.

The list includes a wide selection of drugs, including:

  • NSAIDs
  • Oral hypoglycemics
  • Angiotensin II blockers
  • Anti-epileptics
  • Beta-blockers
  • Antidepressants
  • Antipsychotics
  • Anesthetics
  • Antiarrhythmics
  • Benzodiazepines
  • HIV antivirals
  • Antihistamines
  • Calcium channel blockers
  • They can all potentially interact with CBD.

So, on top of identifying them, consulting with your doctor before replacing your medication with CBD, or complementing your treatment with it, is indispensable. That way you can take the best out of both worlds, be aware of possible interactions and be well informed.