How Does CBD Interact With Medications and Intoxicants?

CBD flower in a prescription medication tube
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According to Single Care, approximately 64 million people in the US have tried cannabidiol (CBD) in the past 24 months, including CBD oils, capsules, vape products, and topicals. A staggering 22% of those have either used CBD to supplement existing prescription medication or replace them completely. 

With so many people supplementing CBD with other medications (or replacing them completely), the concern over unwanted adverse effects when combined is growing. 

All drugs and substances have the ability to interact with each other. CBD is no different. When you consume CBD with, say, antidepressants, ibuprofen, or aspirin, they don’t magically stay away from each other. There’s a blending of the two (or three) as they work within your body.

The question is: How does each type of medication interact with CBD and are there any adverse side-effects?


  • CBD is said to be beneficial against diabetes. CBD and diabetes meds break down by the same enzymes. Could increase or decrease the amount of CBD and diabetes medication (Metformin) in the blood. May lead to adverse effects.
  • CBD and blood thinners (e.g. Warfarin) are metabolized by the same enzymes. CBD may slow down the rate at which Warfarin is metabolized. May stay longer in the body. Possible adverse effects/toxicity. 
  • CBD and central nervous system (CNS) depressants. Both act on special receptors that cause sedation. Could enhance each other’s effects (in theory). 
  • CBD and Adderall (ADHD meds). Inconclusive. More studies needed. May balance each other out or cause unwanted side-effects. 
  • CBD and alcohol. CBD may amplify alcohol’s sedative effects or protect your body from alcohol abuse. More research needed. 
  • CBD topicals are applied to the skin. Don’t go into the bloodstream. Won’t be broken down by the liver. Drug interaction risk is minimal. 
  • Elderly patients should be cautious when consuming CBD and other medications. Age causes liver inflammation and dysfunction. May not metabolize drugs or CBD well. Possible adverse effects. 
  • Speak to your healthcare practitioner before taking CBD with or without other medications. Nothing replaces professional medical advice.

How CBD interacts with your body and other medications

Despite CBD’s advantages, its achilles heel is how it can affect certain medications, as well as how it interacts with intoxicants.

Hand holding CBD flower and medications

In some cases, CBD can enhance the effects of medications and intoxicants. In other cases, CBD may reduce the effects of medications and intoxicants. Why? Put simply, CBD interacts with vital cannabinoid receptors found all throughout your endocannabinoid system (ECS), a naturally-occurring biological system designed to regulate and maintain core physiological functionality. 

CBD also inhibits the cytochrome P450 system found in the liver. The P450 system is composed of valuable enzymes that break down, process, and/or metabolize medications, drugs, and intoxicants. The two most significant enzymes are CYP3A4 and CYP2D6, both responsible for metabolizing many medications you see today, as well as CBD.

When CBD inhibits P450 enzymes, it can essentially slow down or prevent other substances from being metabolized, potentially resulting in unwanted effects and side-effects.  

CBD and Metformin

Metformin prescription medication

How does CBD affect Metformin?

CBD on its own may have beneficial and positive effects for people with type 2 diabetes.

Researchers at the University of Nottingham believe a CBD + tetrahydrocannabivarin (THCV) combination may help reduce blood sugar levels and increase insulin levels. Therefore, CBD products with a full-spectrum hemp extract carry both CBD and THCV may be beneficial here. 

Paired with Metformin? Somewhat unknown at this point. We know Metformin doesn’t metabolize the same way other medications do. In fact, it actually inhibits the liver’s CYP3A4 enzyme the same way CBD does, which could slow the breakdown of both substances. 

In this scenario, there are two possibilities: A reduction of CBD and Metformin in the blood or an increase of CBD and Metformin in the blood for longer periods of time. Either way, this could lead to unwanted toxicity and side-effects.

What is Metformin?

Metformin is an orally consumed medicine designed to tackle type 2 diabetes, as well as polycystic ovary syndrome (PCOS).

Sold under other trade names such as Glucophage, Fortamet, and Glumetza, Metformin was originally derived from French lilac until it was synthetically made in a lab during the late 1920s. 

What does Metformin do to the body?

Metformin is known as a biguanide antihyperglycemic agent. It lowers the amount of glucose (sugar) produced by the liver into your bloodstream, while making your body better-equipped at responding to insulin. 

CBD and blood thinners

How does CBD interact with blood thinners?

Taking both CBD and blood thinners at the same time should be approached with caution.

In a recent 2017 case report, both CBD and Warfarin are both metabolized by the CYP450 system. Warfarin is metabolized by the same enzymes that metabolize CBD: CYP2C9 and CYP3A4.

CBD also competitively inhibits several of its own enzymes (CYP1A1, CYP1A2, etc). 

In other words, CBD essentially competes for enzymes in the same metabolic pathway as Warfarin, slowing down the rate at which it’s metabolized in your body. As a result, Warfarin’s presence and effects in your body may overstay their welcome, potentially causing unwanted bleeding and subsequent harm. 

What are blood thinners?

Blood thinners are special types of medication that help your blood flow correctly through your veins and arteries. There are two types of blood thinners: anticoagulants and antiplatelets. 

Anticoagulants mostly come in pill form and prevent the blood from clotting.

Types of anticoagulants include Dabigatran, Edoxaban, Heparin, and Warfarin. 

Antiplatelets mainly come in pill form and are designed to combat platelets, tiny blood cells that combine to form clots to prevent bleeding. Types of antiplatelets include Aspirin, Dipyridamole, Ticagrelor, Vorapaxar. 

What do blood thinners do to the body?

Despite its name, blood thinners don’t actually thin your blood. They also don’t penetrate and destroy existing clots. Instead, they’re designed to either prevent clots from happening or reduce the growth of already existing ones. 

CBD and central nervous system (CNS) depressants

How does CBD affect CNS depressants?

CBD is an allosteric receptor modulator. It has the ability to change the shape of receptors found in your body, inhibiting or enhancing their behavior. CBD is known as a positive allosteric modulator of GABA-A receptors, meaning it enhances the receptor’s binding ability. 

At a dose of 600mg CBD is known to produce substantial sedative effects by acting on your GABA neurotransmitters (rodent test subjects used). As mentioned, CNS depressants act on your GABA neurotransmitters as well. 

Though still a theory, it’s possible that a CNS depressant and CBD combo could enhance each other’s sedative effects. No clinical research or trials are available to reinforce this theory. 

What are CNS depressants?

CNS depressants is an umbrella term for three different medication subtypes: sedatives (diazepam, triazolam), sedative-hypnotics (zolpidem, zaleplon), and tranquilizers (mephobarbital, phenobarbital).

Each type of medication reduces brain activity.

A reduction in brain activity may be an effective treatment for anxiety, sleep-related disorders, panic disorders, and stress symptoms. 

What do CNS depressants do to the body?

CNS depressants inhibit brain activity via gamma-Aminobutyric acid (GABA) neurotransmitters located throughout your central nervous system.

This causes your brain (and, by extension, body) to slow down, producing a calm but decidedly drowsy effect. Many liken it to drinking a few beers. 

CBD and anti-seizure drugs

How does CBD interact with anti-seizure drugs?

Contrary to common belief, CBD is now officially registered as an anti-seizure treatment.

Epidiolex, a CBD + THC combo drug developed by GW Pharmaceuticals, was approved for use in the United States in 2018. Patients taking this medication are under close medical supervision. 

Epidiolex anti-seizure medication with CBD

However, when CBD (Epidiolex or otherwise) is taken with other medications, unwanted problems may occur.

Researchers believe CBD’s interaction with anti-seizure medication (not Epidiolex) may cause abnormal liver functions and decreased drug efficacy.

What are anti-seizure drugs?

Anti-seizure drugs (also known as anticonvulsants) are a category of different medications designed to control or prevent the onset of epilepsy-induced seizures. 

Some anti-seizure medication includes Brivarecetam, Carbamazepine, Diazepam, and Felbamate. 

Certain anti-seizure medication targets specific symptoms or types of epilepsy. Some are intravenously injected or taken in pill/capsule form. 

What do anti-seizure drugs do in the body?

Anti-seizure drugs do not cure epilepsy and epilepsy-induced seizures. Instead, they prevent and control seizures.

They do this by targeting specific areas of the brain causing seizures. Some will interact with neurotransmitters or latch onto neurons and change the activity of the cell responsible for the seizures. The GABA system and its affiliated receptors within your body could be targeted. 

CBD and Adderall

How CBD affects Adderall

Not much is scientifically known about CBD’s interaction with Adderall, though some speculate it may weaken its effects. 

CBD doesn’t act on cannabinoid receptors the same way THC does; however, it does target other receptor sites such as serotonin (5-HT1A), which may elicit calming and soothing anti-anxiety qualities.

CBD also interacts with GABA receptors, resulting in sedative effects.

Pair this with Adderall’s energizing and focus-promoting effects and the results could be conflicting. 

We assume it’s dose-dependent. The more CBD you take, the more balanced the effects of both become (in theory). We obviously need to see more studies conducted for us to make a conclusive case. 

What is Adderall?

Adderall is a “combination” medication composed of amphetamine and dextroamphetamine. It’s used to treat attention-deficit/hyperactivity disorder (ADHD), though some users consume and abuse it illegally for recreational purposes.

It’s sometimes used to treat narcolepsy, a sleep disorder where sufferers are unable to stay awake. 

What does Adderall do to the body?

Adderall stimulates the central nervous system (CNS) and changes the levels of natural substances found in the brain via important neurotransmitters (dopamine, norepinephrine, etc). 

In ADHD patients, Adderall helps with attention, concentration, and focus, as well as controlling impulsive and unhelpful behaviors. It can also help with cognitive ability, listening skills, organization, and completing tasks. Usually used in conjunction with traditional therapies (behavior therapy, etc). 

CBD and alcohol 

Wine glass with CBD hemp flower

How CBD affects alcohol

There are two main cases for CBD’s effects in combination with alcohol:

  1. CBD amplifies alcohol’s effects (and vice versa)

In the case of CBD amplifying alcohol’s effects, very little research is out there. Most are outdated or too limited to make any conclusions. 

Alcohol and CBD both produce sedation to varying degrees (depending on dose). Alcohol promotes relaxation, reduced inhibitions, and a level of confidence.

CBD does the same but in much subtler ways without a dramatic confidence spike. One study revealed CBD’s sedative qualities have the potential to decrease symptoms of anxiety and improve sleep. 

Taken together? It’s really down to speculation. 

Some believe CBD can amplify alcohol’s sedative effects (and vice versa) or increase each other’s intensity. Others believe that may simply balance each other out. Only time and more research will tell. 

  1. CBD may protect or counteract alcohol’s effects and side-effects

More is known about CBD’s ability to protect or counteract effects and side-effects of alcohol.

Too much alcohol consumption over an extended period of time can result in a number of physiological problems. Damaged cells cause chronic inflammation and other conditions such as liver damage, cardiovascular disease, digestive issues, brain damage, and cancer. 

Fortunately, there’s scope to suggest CBD has the ability to protect your cells against alcohol-related damage. 

Studies on mice revealed something pretty staggering. A 2.5% CBD IV injection and a 5.0% CBD transdermal gel was used on mice with alcohol-induced neurodegeneration. The 5.0% CBD gel reduced neurodegeneration in the brain by up to nearly 50%. Similarly, CBD may also protect against liver damage caused by excessive alcohol consumption via cell and tissue regeneration.

What is alcohol?

Alcohol needs no introduction. Otherwise known as ethanol, ethyl alcohol, or “a good drink at the end of a long day”, alcohol is one of the primary ingredients in beer, wine, cider, and spirits. It’s created from fermented fruit, vegetables, and/or grains. It’s intoxicating and gets you drunk (in high quantities). 

What does alcohol do to the body?

Alcohol is a central nervous system depressant. It slows down cognitive functionality, reaction time, and memory, as well as reduces neural activity, by activating and enhancing GABA neurotransmitters. Depending on dose, alcohol can either be a stimulant (small doses) or a sedative (large doses). In other words, for every drink you have, you’re one step closer to being drunk. 

Approach grapefruit with caution (it acts in a similar way to CBD)

Grapefruit is highly nutritious and an amazing source of essential vitamins and nutrients. However, grapefruit does have its downsides. 

According to the FDA, grapefruit inhibits the very same liver enzyme CBD does (CYPA4). This enzyme is responsible for the metabolism of over 85 medications currently in use today. 

Grapefruit’s inhibitory behavior is very similar to CBD. It can cause the metabolization process to slow down significantly, resulting in higher concentrations of these medications in your bloodstream. As this concentration increases, so do the risks of adverse side-effects and/or overdose (in more extreme cases).

Do CBD topicals reduce the risk of drug interactions?

It’s difficult to say whether CBD topicals reduce the risk of drug interactions. Logically, it would reduce the risk.

With CBD topicals such as CBD cream, CBD lotion, and CBD balm, you’re not consuming or inhaling them orally. Instead, you apply them to your skin for targeted, localized relief. 

Since the aforementioned CBD topicals aren’t known to penetrate through the skin’s outer layers into the bloodstream, most CBD (and other plant compounds) will reside in the skin’s protective layer and interact with receptors there. 

Since CBD isn’t reaching the bloodstream, the likelihood that it needs to be broken down in the liver is very low. No drug interaction (to the best of our knowledge). 

Are elderly people more at risk of CBD and drug interactions?

The elderly population could potentially be more at risk from side effects while taking CBD alone. Some believe the elderly will experience more noticeable sedation than younger CBD users.  

The elderly population are more at risk of liver problems and dysfunction due to increased inflammation during the aging process. Inflammation of the liver can prevent proper metabolism of medicinal drugs, as well as CBD and its cannabinoid counterparts, which may lead to adverse effects and a further decline in liver function. 

We recommend elderly CBD users to be careful when taking CBD alone or with other prescription medication.

Always consult your doctor before taking CBD with other medication

Our aim with this article isn’t to treat, cure, or diagnose you of any medical conditions. We also didn’t write this as a replacement for professional medical advice. If you’re just starting a CBD regimen or you’re already taking CBD with other medications, please talk to your healthcare practitioner.