Does CBD (Cannabidiol) Interact With Birth Control?

Klj711 asked

Hi, I am looking to take CBD oil (with zero THC) for anxiety. Will this interact with hormonal birth control, specifically ortho cyclen? I have done research online and have found conflicting information.

Answer

Cannabidiol, also known as CBD, is a major component of cannabis (i.e. marijuana). While THC (delta-9-tetrahydrocannabinol) is likely more well-known due to its psychoactive effects, CBD makes up almost 40% of cannabis extracts and has a wide range of effects and potential benefits when used medicinally.^[1]

Due to the relatively recent nature of CBD use for medicinal purposes (at least legally), there is a distinct lack of studies when it comes to potential drug interactions between CBD and prescription medication, including birth control pills (i.e. hormonal contraceptives).

There is a theoretical risk of CBD interacting with birth control pills, potentially causing an increase in blood concentrations of the hormones contained in them. However, there are few, if any studies that have tested this.

Below, we discuss the current evidence available regarding CBD and potential interactions with birth control.

Taking Cannabidiol (CBD) While On Birth Control Pills

The two main constituents of marijuana, THC, and CBD are known to be metabolized by the cytochrome P450 system. Specifically, studies have shown that CBD can inhibit:^[2]

• CYP 2C9
• CYP 2C19
• CYP 3A4

Metabolizing enzyme inhibition often leads to increased concentrations of drugs that are typical substrates for a particular enzyme.

For example, take the well-known drug interaction between grapefruit juice and a class of cholesterol-lowering medications, the statins. Consuming grapefruit juice will potentially increase levels of statin drugs in the blood to dangerous levels, all due to CYP enzyme inhibition from grapefruit. A similar theory is in place for CBD and birth control pills.

Birth control pills come in two forms:

• Progestin-only pills (i.e. mini-pills)
• Combined hormone pills (i.e. estrogen-progestin combination pills)

The hormones in birth control pills are, at least partially, metabolized by the CYP enzymes that are thought to be affected by CBD.

Therefore, there is a theoretical interaction where CBD can inhibit the metabolism of the hormones in birth control pills, potentially increasing concentrations in the blood which in turn could increase the risk of side effects including:^[3]

• Breakthrough bleeding
• Increased risk of thrombosis
• Breast tenderness
• Mood changes

Until studies are completed that specifically look at how CBD interacts with birth control pills, we can only make educated guesses.

Interestingly enough, there are many studies that postulate that while CBD does inhibit metabolizing enzymes, it is not significant and the blood concentrations needed to affect these metabolizing enzymes in humans far exceeds what is possible with usual dosing.^[4][5]

It was only recently (in 2017) that a study reported a confirmed drug-drug interaction with CBD and it involves certain anti-epileptic medications.^[6]

As mentioned above, however, there are no such studies that looked at CBD and birth control pills. The lack of published studies confirming an interaction between birth control pills and CBD is likely good news, indicating that one doesn't exist (at least a significant one).

Summary

• CBD is a non-psychoactive component of the cannabis plant and is widely used.

• There is a lack of data available regarding whether or not CBD interacts with birth control pills.

• There is a theoretical interaction based on CBD induced inhibition of CYP metabolizing enzymes. This interaction has not been shown clinically however and studies are conflicting.