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People often assume that because CBD, and other cannabinoids, are natural substances, that they do not pose a risk of any side effects. This is untrue. Although the potential side effects of CBD are minimal compared to other treatment options, they do still exist.

CBD is safe for all the family to take on a daily basis. And according to a report published by the World Health Organisation (WHO) “naturally occurring CBD is safe and well tolerated in humans (and animals), and is not associated with any negative public health effects” but there are potential side effects which you need to be aware of before starting CBD.

The following article is not designed to scare you, but rather arm you with all the available information, so you can be prepared. If these adverse effects do occur, I have also included steps you can take to minimise the discomfort you experience.

What is CBD?

First up, a brief introduction to CBD and how to it works.

CBD is the abbreviation for cannabidiol, one of the many cannabinoids, or chemical compounds, found in cannabis and hemp. While beneficial for wellbeing, CBD doesn’t have the psychoactive properties of it’s more famous cousin THC. Even at high doses CBD will not get you high and it’s safe for all the family to use on a regular basis.

CBD is a wonder of health and wellness because of its powerful interaction with the endocannabinoid system (ECS).The ECS regulates many vital functions within the body including; mood, appetite, sleep, hormone production, and even pain, stress and immune system responses. CBD has been shown to positively influence the endocannabinoid system (ECS) to maintain balance and promote good health.

If you would like to read more about how CBD works within the body please read my article; How CBD works. The endocannabinoid system explained.

Potential side effects

Now let’s move on to discuss the potential side effects of taking CBD. Although CBD is generally well tolerated and considered safe, it may cause adverse reactions in some people. Please note, not everyone will experience these side effects but it is important you are aware of their potential.

1. Dry mouth

Probably the most common potential side effects of using CBD oil isthe unpleasant feeling of dry mouth. While researchers aren’t completely sure why this can happen, a study published in 2006 showed that the endocannabinoid system receptors CB1 and CB2 are present in the glands responsible for producing saliva. When these receptors are activated, the saliva production can drop, leading to dry mouth.  

This side effect is experienced by quite a few people who use CBD oil. However, it is very easy to overcome by maintaining an adequate level of hydration, so that the dry mouth does not occur at all or becomes very minimal.

2. Dizziness or lightheadedness

Another potential side effect is dizziness, although this tends to occur with higher doses of CBD. Dizziness, similarly to dry mouth, may appear immediately after taking CBD oil. It may be accompanied by small headaches, blurred or vague vision and problems with maintaining balance. Temporary drop in blood pressure appears to be the cause.

This typically passes within a few minutes on its own, or can usually be resolved by laying down for a few moments, drinking a cup of coffee or tea, or snacking on a little piece of chocolate. But please be mindful of this potential side effect when you first start taking CBD, and don’t drive if you are feeling dizzy or lightheaded.

3. Drowsiness

After a high dose of CBD oil, some users may experience drowsiness, although some people who are very sensitive to CBD may experience drowsiness at lower doses. The feeling of drowsiness may be in part due to your body relaxing. Many people start taking CBD in an attempt to treat conditions like anxiety or chronic pain. Our bodies are often in a heightened state when battling these conditions, which is exhausting. CBD can help us relax and also reduce pain. When our bodies relax we can often feel drowsy. Listen to your body and rest if you feel drowsy.

It needs to be noted that in some people a completely opposite reaction can occur. Many find CBD stimulating, which gives a feeling of alertness.

When you first start taking CBD, spend a few minutes gauging how your body responds. If you feel drowsy please don’t attempt to drive.

4. Reduced blood pressure

This is one of the most important potential side effect of using CBD oil, as it affects all other issues. High doses of CBD can cause a small drop in blood pressure in some individuals. This will usually occur within a few minutes of the CBD oil entering your system.

This doesn’t happen to everyone, and the worst you should expect is a few minutes of feeling lightheaded. However, if you have any problems with low or high blood pressure, or are taking any medications for blood pressure, talk to your doctor before trying CBD oil.

5. Diarrhoea and nausea

Diarrhoea and nausea have been reported as a side effect by some CBD users, although these symptoms are more likely to occur in people who already have pre existing digestive disorders. The cause may not only be CBD, but also the carrier oil which is used e.g. Olive oil or MCT oil, so please check all the ingredients listed. Symptoms normally only last a couple of weeks. Drink plenty of water to avoid dehydration.

6. Delay, or even inhibition of certain medicines’ effects

CBD can also interact with several medications because it inhibits the activity of specific liver enzymes, in particular cytochrome P450, which is responsible for metabolising nutrients.

The way that CBD is metabolised by your body can interfere with how your body normally metabolises other drugs you take. If those other drugs aren’t metabolised properly, they can hang around and stay in your system longer than you want. This can cause negative side effects and complications.

This side effect can normally be avoided by leaving a 2-4 hour gap between your medication and CBD.

If you are taking other supplements or medication please check with your GP or pharmacist about any possible interactions. Typically a 2hr gap is required between CBD and your prescription meds but certain drugs like: Beta blockers, blood pressure tablets, anticoagulants and any other medication that carry a grapefruit warning, generally require a 4hr gap.

Before you start using CBD oil, discuss it with your doctor to ensure your safety and avoid potentially harmful interactions.

7. Herxheimer Effect or “Herxing”

Some adverse effects may be caused by a phenomenon called “Herxing”.

People commonly report feeling worse before they feel better, when they first start taking CBD. Common symptoms include headaches, itching and rashes on the skin. These symptoms appear to last anywhere from a few days to a few weeks, but they disappear as quickly as they started.

Many believe a phenomenon called “the Herxheimer reaction” or “Herxing” is to blame.

What is Herxing?

Herxing is a short term reaction to the body as it detoxifies. This is common when people take antibiotics and it is sometimes referred to as the “die off effect”. It is quite common to experience flu-like symptoms which can include a headache, joint and muscle pain, body aches, a sore throat, sweating, chills or nausea. If it occurs, it generally lasts a few days but can last for a week or more.

Herxing is actually helpful to your system as it is creating a detoxifying effect. In basic terms, you have ‘herxed’ because the effective treatment releases toxic chemicals from the cell walls of dying bacteria.

Our immune system reacts to these toxins, but we are not able to eliminate them quickly enough. As a result, the toxins are capable of causing some unpleasant symptoms, and the original symptoms may even get worse for a short while.

Many ask why CBD would cause herxing, as it’s normally associated with antibiotic treatments. But CBD has powerful antibacterial and antioxidant properties, so it isn’t really a surprise that it could also lead to the herxheimer effect.

You can minimise these unwanted side effects by introducing CBD slowly, and drinking plenty of water.

Biphasic properties of cannabinoids

Although not a side effect as such, it is important that we acknowledge the biphasic properties of cannabinoids like CBD. But what does “biphasic” mean?

A biphasic medicine or drug is one which can have different effects on the user depending on the concentration levels in the blood. Alcohol is a biphasic drug too, it works by acting as a stimulant until blood alcohol levels reach a certain percentage (0.05%). After this point, the amount consumed acts as a depressant and causes sedation.

When it comes to CBD, low doses may be stimulating while higher doses appear sedating. But with some people low doses may improve conditions like anxiety, while larger doses may actually heighten anxiety. Please be aware of this when you start taking CBD.

This is why we always recommend the “low and slow” approach to introducing CBD. And also why less is often more when it comes to cannabinoid therapy.

“Low and slow” approach to introducing CBD

Many of these side effects can be avoided or minimised by using the “low and slow” approach to introducing CBD.

I will explain this is more detail in my next post about CBD dosing. But the general advice is to start with 2-3mg of CBD, 2-3 times a day. Stay with this dose for a week, and then gradually increase if necessary.

Please note; this approach is not always suitable. Some medical conditions, like epilepsy, may require higher doses of CBD from the outset.

Is it possible to have an allergic reaction to CBD oil?

While it appears to be a rare side effect, it is possible, as with all substances, to have an allergic reaction to CBD oil. Please check all the ingredients in any CBD product before you buy, against any substances you are known to be allergic to.

When you first start taking CBD, take the smallest dose possible so you can gauge how your body responds. This is particularly important if you suffer from medical conditions like MCAS or are known to have multiple allergies. If in doubt please consult your GP.

Please consult your doctor

Research has shown that CBD can be an effective treatment option for a myriad of symptoms and medical condition. The reason for this is it’s positive interaction with our native endocannabinoid system.

But although CBD is a safe options for all the family to use on a regular basis, it does come with some potential side effects. These side effects are mild compared to most prescription medication, and can be avoided or reduced by taking some simple steps.

But please be aware of these potential side effects when you choose to start your CBD journey.

Please note; I am not a medical professional. If you have any concerns, please consult your GP before commencing CBD.

If you would like to find out more about CBD, or you have any specific questions you need answering, please head over to my Facebook page CBD Resource Centre

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