Who Shouldn’t Take CBD?
We often talk about the potential health benefits of CBD. In surveys about how Britons consume CBD, they report that they primarily use it to help with chronic pain and inflammation and support their mental health. A related goal is achieving better sleep patterns. Since CBD may help people manage their anxiety, it should be a helpful ally when sleep is out of reach—or so the thinking goes.
Because CBD is plant-based, most people assume that it’s completely safe and wholesome. While it is true that high-quality CBD comes from industrial hemp and requires limited processing to isolate the cannabidiol, it is still a botanical substance that can interfere with other medicines and impact certain health conditions.
Therefore, talk to your GP before taking CBD and discuss all your health issues and any medicines you are on, including over-the-counter ones.
Botanical compounds have side effects
It is a common misbelief that botanical compounds have no side effects. While they may help with certain ailments and conditions, they still do have potentially dangerous side effects. Some natural compounds interact with medicines while others shouldn’t be taken if you have certain conditions.
For example, garlic may lower blood pressure—which is usually a good thing. If you already suffer from hypotension, though, this could be a problem. Garlic also thins the blood, which can be dangerous if you are about to undergo surgery as it could cause haemorrhage.
In another example, St. John’s wort may help fend off depression and anxiety—but also interacts with conventional anti-depressants. Taking the two compounds together could have a serious impact on someone’s health.
As for ginseng, it interacts with blood thinners. And echinacea, treasured by herbalists for its potential strengthening of the immune system, can cause allergic reactions.
The simple fact is that natural and plant-based compounds can still carry their own complications. Just because something comes from nature doesn’t implicitly mean that anyone can take it—or we’d be able to pick mushrooms indiscriminately.
So, who shouldn’t take CBD?
CBD interacts with other medicines
The first group of people who should be careful when using CBD is anyone who’s already on medication. This is primarily because of the way the body’s metabolism works.
CBD, medicines and the CYP450 enzyme
CBD may interact with other medicines. The reason is that it is metabolised by the liver, where most medicines are also metabolised.
Enzymes in the liver break down medicine and then release them into the bloodstream. The most common liver enzyme is CYP450.
Among other compounds, CYP450 also metabolises CBD. When CBD reaches the liver, it has to compete with other medicines for priority: which one will be metabolised first? In this case, whichever substance reaches the liver first is metabolised to the fullest. Other substances are left behind or linger in increased doses until they are metabolised or expelled from the body.
The body can only metabolise specific amounts of medicines. When these levels are exceeded, the body disposes of the excess. Until such excess is eliminated, though, it can create problems.
When CBD and other medicines compete against each other, some of them lose their potency while others build it up. For example, if you are taking CBD but also a blood thinner twice a day, the first dose of blood thinner could be still lingering in your liver when the second dose comes through. You can then have too much blood thinner in your body. This can be a particular risk if you are about to have surgery, for example.
Conversely, if the blood thinner gets metabolised first, CBD is left to sit around until its turn comes. Too much CBD could thus build up in the body. Although it’s practically impossible to overdose on CBD, too much of it can produce side effects such as drowsiness, dry mouth, and nausea.
CBD interacts with other medicines
It is has been observed that CBD may interact with anti-depressants, blood thinners, blood pressure medicines, some antibiotics, heart medicines, thyroid medicines, antihistamines, anti-epileptics, corticosteroids, and immunosuppressants.
Researchers are still studying the mechanisms behind such interactions, trying to determine dosages and counterindications. We are still a long way from reaching a conclusion, though.
How is CBD taken?
Another criterium that affects how CBD interacts with other medicines is the way it is ingested. Vaping, for example, bypasses the gut and enters the lungs immediately. Because of the high bioavailability—the percentage of CBD that enters the blood—we don’t know how much residual CBD will be left behind to be metabolised.
Sublingual CBD is taken under the tongue so that it can be absorbed through the capillaries—blood vessels under the tongue. Just how much is absorbed and how much is swallowed, though, can be unclear.
Another obvious factor is dosage. How much CBD you take will determine what kind of effect it has on you.
Even frequency plays a part in this: how often you take CBD can affect how it interacts with other medicines. Smaller and frequent doses are more easily manageable than larger ones, since the latter monopolise the available CYP450 enzyme at the expense of other medicines.
CBD can impact existing health conditions
Because CBD is metabolised by the liver, people with pre-existing liver conditions are advised to be cautious about taking CBD.
Likewise, people with underlying kidney or heart conditions should consult with their GP before taking CBD, as the latter may worsen their health problems.
Epilepsy is another condition that requires special attention when it comes to CBD. CBD has been found to help alleviate epilepsy episodes and is used medicinally to help treat two rare forms of children’s epilepsy. It may, however, have an effect on the condition itself and may interact with other epilepsy medicines.
Glaucoma sufferers is another group who should avoid CBD, as it may increase intraocular pressure. This may seem strange since THC has the opposite effect and is commonly prescribed to relieve glaucoma symptoms, but it just shows how similar compounds can have wildly different effects on the body.
Finally, pregnant women are often advised to avoid CBD as it is unclear whether it can cross through the placenta and reach the embryo. CBD interacts with the human endocannabinoid system and we are still unsure how well-developed the embryo endocannabinoid system is and how it can tackle any CBD crossing through the placenta.
NHS and cannabis prescriptions
The NHS can prescribe cannabis-based medicines for very specific conditions. In some cases, the medicines also contain THC, which is still illegal in the UK.
Currently, the NHS prescribes cannabis-based medicines for specific forms of children’s epilepsy, patients with multiple sclerosis who suffer from spasticity, and people undergoing chemotherapy who are experiencing excessive vomiting, nausea, and sickness. The most common CBD-based medicines are Epidyolex, Sativex, and Nabilone.
Aside from CBD-based medicines, the NHS can also prescribe medical cannabis. It is estimated that 20,000 people have been prescribed medical cannabis, particularly for autism, PTSD, anxiety, depression, and Parkinson’s disease, among others.
Natural remedies have been around for millennia
There is increasing acceptance of natural remedies as possible alternatives to conventional chemical medicines.
After all, people have been making and taking natural remedies for centuries and there is a renewed interest in the effects of botanical therapies. With more than 300,000 different plants in the world, it’s no wonder that people have been using these for millennia to cure ailments and conditions.
It should be remembered that antibiotics have been around for a little bit more than a century: penicillin, the most famous antibiotic, was only discovered in 1928. Paracetamol, the most common pain-management drug, appeared commercially in the 1950s and aspirin, the first NSAIDs, is just 126 years old. This gives us a clear image of how recent modern pharmacology is.
Thanks to nature’s gifts, humanity still managed to survive, grow, and thrive before modern drugs and medicines made our lives better, easier, and safer. People traditionally handled their ailments, conditions, and pains with herbal remedies and botanical solutions. Through trial and error, they discovered that garlic may help lower blood pressure, ginseng may help fight inflammation, elderberry may help with colds and the flu, and St. John’s wort may be beneficial for depression. Turmeric was thought to have anti-inflammatory qualities and valerian was used for anxiety.
In the minds of people, CBD joins this long line of botanical wonders. As it becomes more popular and grabs people’s attention, consumers wish to evaluate its benefits for themselves. Because it is plant-based and botanical, they often assume it to be safe.
It is possible that CBD may have fewer side effects than other medicines. A recent study showed that people with fibromyalgia often substitute CBD for opioids and other pain medicines because they feel that CBD has fewer side effects and helps them manage their pain symptoms better.
CBD over the counter
Because the NHS is reluctant to prescribe CBD medicines, people are turning to buying CBD as a health supplement. CBD oils, gummies, and edibles can be found across the United Kingdom.
If you feel that CBD can help you manage a health condition better, consult first with your GP to check if CBD may affect an underlying condition or medication you are on. CBD might be a natural, plant-based remedy but, like all other botanical compounds, it interacts with our body in sometimes unexpected ways. Start with a low dosage and see how your body reacts. You can then increase the dosage until you reach the expected effect.
When choosing a CBD product, check out online CBD reviews, and make sure it’s from a trustworthy CBD manufacturer. Look for a Certificate of Analysis (CoA) to check the product’s exact potency and CBD content. The CoA is particularly useful to verify that the THC levels are below 0.2%, which is the legal threshold in the UK.
Once you are sure about your choice, there is nothing stopping you from trying CBD for yourself and finding out the reasons behind its popularity!