What is the Grapefruit Rule for CBD?
For those who take regular medications, warnings about grapefruit may be familiar. The grapefruit rule doesn’t apply to all medications, but multiple commonly prescribed medications are contraindicated with grapefruit. When this is the case, extra considerations regarding CBD use are important. This typically means leaving a longer gap between the medication and CBD. However, some medications may not mix well with CBD regardless of the gap, so speaking to a doctor or pharmacist before taking CBD when taking regular medication is always the safest course of action. This article covers what the grapefruit rule is in terms of medications and how it applies to CBD.
What is the grapefruit rule?
The grapefruit rule refers to the fact that some medications come with a grapefruit warning, which means that they are contra-indicated with grapefruit. This warning is intended to stop people who take these medications from consuming grapefruit or anything containing high quantities of it, such as grapefruit juice. While this may seem odd, it’s for a very good reason. Research has shown that if people ignore this warning and eat or drink grapefruit while on their medication, it can cause an increased concentration of the medication in their bloodstream. This can lead to unwanted and potentially harmful side effects.
How does the grapefruit rule apply to CBD?
There is a type of chemical in grapefruit called furanocoumarins. Furanocoumarins are able to inhibit the CYP3A4 enzyme, which helps break down medications and supplements. Similarly, CBD is thought to inhibit this enzyme. It can therefore also result in similar effects as grapefruit, such as slowing the rate at which a medication is metabolised. This means that if a medication is highly likely to be impacted by grapefruit, it’s also highly likely to be impacted by CBD.
This is why, at Simply CBD, we double the recommended gap to four hours between taking CBD and medications when the latter is contra-indicated with grapefruit. Additionally, we recommend that users speak to a doctor or pharmacist about the safety of using CBD products when taking their medications.
What if a medication doesn’t have a grapefruit warning?
If a medication is not contra-indicated with grapefruit, this doesn’t mean it won’t be impacted by CBD if it’s taken at the same time. The body still needs to metabolise both, and doing so simultaneously can produce different results than if they were metabolised one by one. Therefore, leaving at least a two hour gap is still necessary. We also still recommend that users speak to a doctor or pharmacist about whether taking CBD is safe with their specific medications. In the context of CBD, the grapefruit warning simply identifies medications with an increased likelihood of interactions with CBD.
Does the grapefruit rule apply to all CBD products?
Some CBD products don’t require a gap between medications and supplements. As a general rule, anything ingestible, such as oils, water soluble CBD, gummies, and capsules, require a gap. This applies to both medications that are contraindicated with grapefruit and those that aren't, the difference being the length of the gap. However, other products that don’t enter the digestive tract, such as balms and salves, can be used at the same time as medications and supplements. This even applies to those that are contraindicated with grapefruit.
Here are the key points to remember about the grapefruit rule and how it applies to CBD:
- Some commonly prescribed medications are contraindicated with grapefruit, meaning those who take the medication should not consume grapefruit.
- CBD impacts certain enzymes in a similar way to grapefruit, which means a longer gap between CBD and contraindicated medications is necessary (at least 4 hours).
- Checking with a doctor or pharmacist about if certain medications are safe to take with CBD before starting CBD is always the safest course of action, regardless of the grapefruit rule.
- Medications that are contraindicated with grapefruit are more likely to interact with CBD if taken too close together.
- Medication gaps including the grapefruit rule apply to all ingestible CBD products, while other product types like balms and salves are exempt from the rule.