What are the potential side effects of CBD oil?

It’s only natural that when you are trying something for the first time, it can be nerve wracking.  It’s important to do your homework and know all the potential pitfalls.  So what exactly are the risks and potential side effects of CBD oil? And can you take too much? Read on and find out.

hemp plant in the sun 

Can you overdose on CBD oil?


Let's start by saying CBD is extremely safe to take. In 2017, a report by the World Health Organisation said that CBD is both safe and non-addictive.


| CBD is generally well tolerated with a good safety profile.


Even at extremely high doses, scientific research shows that CBD is well tolerated by us. For example, a study done in 2016, showed that people who consumed extremely high amounts of purified CBD (1500mg) tolerated it ok. Given that most people consume around (10 - 50mg), you can see how this compares.


That said, the UK Food Standards Agency recently warned against consuming more than 70mg of CBD a day. Although this recommendation  was drawn from purified CBD oil with children and not whole-plant CBD oil, it’s still something we adhere to.


What are some of the known side effects of CBD oil?


At low doses, there are very few known side effects from CBD oil especially if you follow the rules when trying CBD for the first time.


However, there are some reported side effects from extremely high doses of CBD. For example, a study done in 2017 with children that have dravets syndrome noted some of the following side effects:

  • Diarrhoea
  • Fatigue
  • Reduced appetite
  • Abnormal results on liver-function

Although it should also be noted that the study also showed big reductions in convulsions for the children who consumed CBD. 


Can CBD interact with medication?


If you are taking any medication, make sure to talk to your physician and/or ask them to check on you and make sure that whatever you’re doing is safe for you. 


CBD is known to act as an inhibitor of P450 isozymes so if you are taking any medications, ask your doctor if any are metabolised by the cytochrome P450 system before taking CBD.


Examples of P450 inducers are:

  • Carbamazepine
  • Rifampicin
  • Phenytoin

Examples of P450 inhibitors are:

  • Sodium valporate
  • Ciprofloxacin
  • St John’s Wort
  • Sulphonamide
  • Cimetidine
  • Omeprazole
  • Antifungals
  • Amiodarone
  • Isoniazid
  • Erythromycin
  • Clarithromycin

Adapted from the Medical Clinician's Guide to CBD