What are the side effects of CBD?

cbd side effects

What are the side effects of CBD?

Written by Zaneta Pacific and reviewed by our qualified expert, Moyra Cosgrove, Head of Nutrition at Naturecan, SENR Registered Nutritionist and DProf candidate at LJMU


  • CBD (short for cannabidiol) is a popular supplement extracted from hemp (Cannabis sativa).
  • CBD is safe and well-tolerated by most users, but like most supplements and drugs, it might have minor side effects for some.
  • People with medical conditions should consult their doctor before using CBD.
  • Pregnant and breastfeeding women should avoid CBD altogether.

The WHO said that “CBD is generally well-tolerated, with a good safety profile”, though we still have a lot to learn about its effects on the human body.

While most producers focus exclusively on the positives, we believe it is crucial for our customers to be well informed before they start using CBD oil – not only about the potential benefits of CBD, but also any potential side effects that might occur.

What are the side effects of CBD, and do they concern you? You can find the answers in this article.

What is CBD?

Before discussing CBD side effects, we need to make sure we all know the answer to one question – what is CBD?

CBD, short for cannabidiol, is a chemical compound found in the cannabis plant. Most CBD is extracted from hemp – a type of cannabis plant known for its high CBD content. 

CBD has been the talk of the town over the last few years due to its potential health benefits. Early studies show that CBD may provide support in dealing with symptoms of various health issues.

But, before we move on, it is important to mention that CBD is not a drug but a food supplement, just like magnesium, vitamin D and omega-3 fatty acids. This means that while it can be sold and used legally, your doctor will not prescribe an over-the-counter CBD supplement to cure any of your illnesses. 

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Is CBD safe?

CBD is generally well-tolerated and safe, and any potential CBD oil side effects are rare. However, there are certain groups of people who should be extra cautious when using CBD. 

A good rule of thumb is that if you require regular medication or medical supervision, it is important to consult your doctor and explore the potential interaction between your condition and CBD.

Fortunately, this does not mean you can’t reap the benefits of CBD. All it means is that you should be more aware of the potential CBD side effects and that it might be a good idea to communicate with your local GP before you introduce CBD into your daily life. Additionally, if you are pregnant or breastfeeding, you should avoid CBD altogether.

We recommend you keep a close eye on how your body reacts to CBD and how much of it you are taking. The perfect dose will bring the best results and help you avoid side effects, which tend to show up when the dosage is too high.

Is CBD legal?

CBD is legal in many countries around the world, including the UK, USA, Canada and the EU. But this is only true as long as it does not contain more than the allowed levels of THC (an intoxicating cannabinoid), which vary from country to country. 

The UK is one of the stricter countries when it comes to how much THC is permitted in CBD supplements. This means no detectable amount of THC whatsoever is allowed in any CBD oils, making CBD isolates and broad-spectrum CBD the only legal products in the UK.

Considering that using THC might cause some side effects, this is good news. 

So what’s the bad news? Not all companies respect this law equally, and any products purchased from sketchy producers might have a higher content of THC than what is written on the label. 

A recent study conducted on different CBD products available in the UK found that only 38% of products contained the advertised levels of CBD. Additionally, 55% of the tested products had more THC than expected or legally allowed. 

So while, in theory, CBD is legal, products purchased from an unreliable source might not be.

What are the potential benefits of CBD?

Researchers are currently exploring the impact CBD can make on how people with various health problems feel. These problems include, but are not limited to, sleeping issues, an overactive immune response, anxiety, stress, inflammation or changes in appetite.

Some studies, such as the study on CBD’s impact on anxiety levels in public speaking, or CBD’s impact on the lives of people who have arthritis, show that there are reasons to be excited about the potential benefits of CBD. 

Since CBD was discovered in the 1940’s, scientists have been constantly learning new things about the benefits of this particular cannabinoid. While not enough research has been done on CBD to earn it official medical approval, thousands of scientific papers and experiments have been published in respectable scientific journals, such as the Journal of Cannabis Research.

There are so many potential benefits and uses of CBD that we decided to write a whole article about it here.

cbd benefits

Are there any potential side effects of CBD?

Does CBD oil make you tired? Can it lower your blood pressure? Will it impact your digestive system?

These are just a few questions you might have regarding CBD and its potential side effects.

And while CBD oil side effects are rare, we think it’s important to address these questions and provide you with a list of potential side effects some CBD users may experience.

These uncommon CBD oil side effects include:

  • Drowsiness
  • Nausea
  • Dry mouth
  • Interaction with certain medication
  • Ability to cross the placenta in pregnant women
  • Ability to be passed to a baby through breastfeeding
  • Potential increase in liver enzymes 

When used in very high doses, CBD can also cause additional side effects, such as:

What causes these CBD side effects?

Even though most of these side effects occur only after taking a very high dose, we believe it is better to be safe than sorry. For this very reason, people with pre-existing conditions should talk to their doctor, BEFORE taking CBD, carefully monitor their body’s response to the supplement, and stick to lower doses just to be safe. 

People who use certain types of medication, such as blood thinners or liver disease medication, might find that CBD will either decrease or increase the impact of their daily medication. 

Does CBD oil make you tired, even though you do not take any other medications or have any underlying health conditions? If so, then you might be using too much CBD. Adjust the dose and see if this makes your CBD side effects go away.

Didn’t help? Then you might be using a low-quality product.

It is shocking how many bad CBD products are available on the market. Products made of low quality and contaminated hemp, with more THC than stated, are flooding the market.

Additionally, low-quality CBD products might contain toxic heavy metals and other unwanted ingredients that high-quality CBD oil producers make sure to remove. 

Some people might have an immediate adverse reaction to such ingredients, especially if they are very sensitive and prone to allergic reactions. Others may feel fine at the beginning but then suffer from long-term effects, which could become dangerous. 

Therefore, if you have any suspicion the CBD oil you are using comes from a questionable source, get rid of it. 

How to minimise the risk of side effects

Fortunately, there are a few things you can do to minimise your chance of experiencing CBD oil side effects significantly.

First of all, only use high-quality CBD products from producers who are transparent about their testing process. Only go for products that have been independently tested, as in-house testing can’t always be trusted. 

Second of all, do not take CBD together with any medication, and make sure to talk to your GP if you are on daily medication or have low blood pressure. 

Third of all, start with small doses. Observe how you feel and how your body reacts, and only increase the amount of CBD you are taking gradually. If at some point you hit a dose that makes you feel tired, nauseous, or simply doesn’t feel right, go back to a lower dosage.

Contraindications of CBD

While we have talked about it already, we believe this point to be critical, so we want to repeat it. CBD oil side effects should concern certain groups of users more than others. 

You should not take CBD before talking to your doctor first if you are currently:

what are the side effects of CBD?

If you are still worried about any other potential contraindications of CBD, you should speak with your GP. Your doctor can always advise you on which supplements can benefit you and which ones you should avoid. All you need to do is ask.

Potential benefits of CBG

Have you heard of CBG (cannabigerol)? It’s another non-intoxicating cannabinoid derived from the Cannabis sativa plant, with some similar properties to CBD. However, it does not come in as much abundance as CBD or THC.

We know way less about this cannabinoid than we do about CBDStill, based on what we do know, CBG might turn out to be helpful for people suffering from symptoms of inflammation, pain, anxiety, glaucoma, bladder dysfunction and neurodegenerative diseases

It also shows some promise in supporting people with gastrointestinal conditions, such as irritable bowel syndrome (IBS), which is commonly managed with the help of a strict diet.

what is cbg?

Side effects of CBG

CBG has not been researched nearly enough for us to know what side effects to expect. So far, it seems that CBG and CBD side effects are very similar, but as CBG is more potent than CBD, the potential side effects can occur with smaller doses.


CBD is popular for a reason. Many people find it to be very beneficial, if not life-changing, and can no longer imagine going back to a life without it. 

While potential CBD oil side effects are rare, certain users need to be more careful about using CBD than others

If you have any pre-existing conditions or take prescribed medication regularly, always make sure you speak to your GP before including CBD in your diet. The chances are that with slight adjustments, such as taking CBD hours before or after you take your regular medication, or just decreasing the dosage, you take your regular medication or just decreasing your dosage, you will still be able to take advantage of the benefits of CBD. But again, this is something you should discuss with your GP.

And who knows what the future holds. Perhaps CBD, just like vitamin D, will be available as a supplement in small doses, but as a prescribed medication in higher ones. 

But until then, make yourself aware of all the potential CBD oil side effects and only purchase CBD products from reliable, trusted and competent resources.


Disclaimer: There is currently insufficient evidence to support the use of CBD in the condition(s) mentioned above and this text by no means reflects recommended uses. Always seek the advice of your healthcare professional if you are taking prescribed medication or are thinking of using CBD for your condition.


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