A few years ago a survey by the NHS reported that almost half of adults in the UK were taking prescription medicines.
As we and many others have written about in the past, more and more people are using CBD to support their health and wellbeing, whether it be for pain relief, anxiety, stress, better sleep or a variety of other reasons. CBD is a plant extract and so is widely believed to be safe but, just as we know that combining two prescription medicines may alter their affect or alcoholic drinks for example could do the same, it is important to consider what interaction there may be between CBD and the medication you are on.
Research has shown that CBD is safe and has few side effects but, when taken in high doses, CBD can temporarily inhibit your CYP 450 enzymes. These are found in your liver and are responsible for metabolising foreign compounds in the body. In fact, it is estimated that as many as 60% of pharmaceutical drugs are metabolised by CYP 450 so any competing interaction by another compound could alter how long it takes for a certain drug to pass through your system. In other words, the calculations carried out by your doctor when making the prescription may become inaccurate.
If your body is metabolising a medication too slowly, you may have more medication in your system at one time than intended — even if you’ve kept to the correct dose. An increased level of a medication in your system could exaggerate its effects, including potential side effects.
Incidentally, the reverse is also possible. Some prescribed medications themselves inhibit CYP 450 enzymes. Taking CBD in combination with these may mean your body won’t be able to process the CBD as effectively.
You may have been told in the past not to eat grapefruit when on certain medication. Grapefruit contains furanocoumarins which bind with, and neutralise, CYP 450 enzymes which can cause excessive levels of a drug to get into your bloodstream. CBD can have a similar effect. Pending taking medical advice (and we recommend you do that), you could use the “grapefruit warning” as a rule of thumb to determine whether you should avoid CBD whilst using a particular medication.
How much CBD will affect CYP 450 depends on several factors – the CBD dose itself, the form of administration and, of course, you (we’re all different). Studies have shown though that CBD generally does not affect CYP 450 when taken in small doses.
At present, there is no known CBD interaction with paracetamol but studies have shown that CBD can increase the effects of drugs with a risk of blood-thinning (for example, ibuprofen).
However, whether you are taking CBD with medication or not, it is important that you get your CBD from a reputable supplier. Always ask for a certificate of analysis or lab report and, for oral products, ask for a safety data sheet. For obvious reasons, it is important that you know what you are taking and, of course, exactly how much CBD is in each dose.
Keep in mind that topical CBD, like our skincare and massage range, could be an alternative solution if your reasons for taking CBD are to target a particular area. Unlike oral products, topically applied CBD does not enter the bloodstream and so any interaction with an orally taken medication would not occur.
As a final word, we need to remind you that we are not doctors and nothing we have said in this blog should be taken as a substitute for medical advice but hopefully we have helped set out some of the background and suggest some of the questions to ask your doctor. Even if you are prescribed a medication that is believed to interact with CBD, your doctor may be able to formulate a plan that enables you to take them in combination.