Before we get started, there’s one thing we need to clarify:
Our team has gone to great lengths to develop an in-depth understanding of the interactions and side effects of taking CBD. With that being said, we are not doctors! And even if we were, we are not your doctor!
While we always proceed with extreme caution and conscience with all our enquiries, this post should, at best, be regarded as a compilation of information that’s generally known. And, of course, we always try to reflect the latest research that’s been published on PubMed, the leading global resource on biomedical and life sciences literature.
Nevertheless, if you’re eager to try CBD and have serious concerns about the negative side effects and interactions (such as drug interactions with other medications you take), always bring this up beforehand with your doctor!
CBD IS CONSIDERED TO BE “SAFE” (ARE CBD PRODUCTS HARMFUL?)
Cannabidiol, or CBD for short, is a naturally occurring molecule that’s obtained from cannabis and hemp plants (Cannabis sativa L.) and has enjoyed an ever-growing fan base in Germany and around the world in recent years. Many benefits are ascribed to this natural substance, from inflammation and pain relief, to concentration and sleep aids.
But can something that seems to remedy so many issues actually be safe too? There must be a couple downsides, right? One of the first questions that CBD first-timers often ask is if CBD oil causes any side effects and if so, what are they? Many also ask if CBD products interact with other substances and medications? And what about taking CBD during pregnancy and breastfeeding?
It is often assumed that a “natural” substance automatically means it’s a “safe” one too. Yet this is a common misconception. Just because something is taken from nature doesn't mean it’s harmless. Even too much water can harm our bodies. So we need to take a closer look at what’s going on.
Having said that, it’s important to consider that experts from the World Health Organization surveyed existing research on CBD and in November 2017 they published a report that clarified the following:
- CBD does not alter your mind (So it doesn't get you high!)
- CBD is well tolerated by humans and animals
- CBD poses no threat to public health
- CBD does not provoke any mental or physical addiction
Based on these findings, the World Health Organization deemed that CBD has “a good safety profile.”
Nevertheless, taking CBD oils and other products, especially in very high doses, can lead to unpleasant and undesirable effects (read here for tips on how to dose CBD). So far, there are only a few long-term studies on CBD’s possible side effects and drug interactions, and that list is rather short.
CBD SIDE EFFECTS: THESE SIDE EFFECTS CAN OCCUR WITH CBD
Despite the lack of sustained studies on CBD, some potential side effects have been reported thus far. Even so, these often have much to do with factors related to the administration form (oil, capsules, etc.) and the time of ingestion. In the following, we’ll glance at which side effects are currently known:
Hemp extracts are often used to treat insomnia and sleep issues, but CBD’s sleep aid effects are still contested. If you feel that CBD is making you feel too drained, it’s recommended to either reduce your dose or stick to taking CBD in the evenings.
Ironically, CBD can provoke the opposite of fatigue too. Although it’s very rare, some people who take CBD experience insomnia, sleep disturbances and restlessness.
Low blood pressure
Studies have shown that CBD can lower blood pressure, but the effect usually fades away after just a few minutes. Caution is advised if you’re already taking medication to lower your blood pressure. It’s especially advised in this case not to take CBD without prior consultation from your doctor.
Drowsiness and dizziness
The low blood pressure effects brought on by cannabidiol can lead to dizziness. However, this side effect is not very common and can largely be avoided with adequate fluid intake. If you are new to CBD on your body, be careful the first time and try not to take too much.
This side effect is due to deceased saliva secretion, which can result from CBD oils and sprays and can lead to a dry mouth. Yet this issue can be troubleshooted by increased hydration or switching to CBD oil-filled capsules instead.
Loss of appetite
This effect can be both desirable and undesirable. For some people, CBD can be used as an appetite suppressant to treat obesity. But those who aren’t concerned with losing weight, or who are seriously ill and suffer from emaciation and anorexia might want to avoid cannabidiol as a precaution, as the possible appetite-suppressing effects can promote unwanted weight loss. That said, the loss of appetite disappears a few hours after taking CBD.
Diarrhea is one of the most commonly reported side effects of CBD, but it is not yet clear what exactly causes it. Diarrhea is a standard reaction when the body is fed something it’s not used to. In some cases, it might also have something to do with the carrier oil used in the CBD extract. Diarrhea tends to occur more in people who have taken high doses of CBD over the course of a long period of time.
Allergic reactions to CBD are rare but can occur. Allergies to cannabis do exist, and a study from 2018 showed that people with allergies to cats, mold, house dust mites and pollen have an increased risk of developing a cannabis allergy. There are also people who might be allergic to certain terpenes from the hemp plant. So if you know you’re prone to allergies, be careful with broad- and full-spectrum CBD products as they contain terpenes, whereas CBD isolate products do not.
Increased intraocular pressure
A recent study in mice suggests that CBD can increase the pressure in eyes, though more studies are needed to come to a clear conclusion. Those who already suffer from increased intraocular pressure (glaucoma) should steer clear of CBD, at least not without a consultation with their doctor.
WHO SHOULD AVOID CBD AND WHY?
Even though CBD is generally considered to be safe and the possible side effects are often considered to be very manageable, CBD still presents a lot of unanswered questions. As a result, the following groups are probably better off avoiding CBD.
Women who are pregnant or breastfeeding
There’s much dispute about whether or not CBD is safe to take during pregnancy. That’s why we would also advise against taking CBD in these cases! A study from 2010 showed that synthetically produced CBD might have a negative effect on pregnant women during labor. Another study from 2019 suggested that CBD and THC may cause growth issues in developing embryos. In addition, research has also shown that CBD affects certain proteins, which could, in turn, interfere with the normal development of the placenta.
People with liver disease
In a study on mice, researchers found that mice that received very high doses of CBD developed liver damage within 24 hours, which was fatal in many of the mice. While experts point out that there is probably no reason to worry about this same phenomenon in humans, since hardly anyone takes such high doses, the package insert for the CBD-based registered medicine Epidiolex also warns of potential liver damage if taken long-term. So, if you have a damaged liver or are taking medication that could affect your liver function, talk to your healthcare professional before trying CBD.
DOES CBD INTERFERE WITH OTHER DRUGS?
CBD can affect the activity of various enzymes in the body, some of which also play a role in how different drugs are metabolised in the body. This can cause medication to work differently than intended. A possible interaction between CBD and the following drugs has been identified:
- pantoprazole and omeprazole (to treat heartburn, acid reflux and other conditions)
- Marcumar and warfarin (to prevent blood clots)
- Diclofenac (to treat pain and inflammation)
- Risperidone, haloperidol and clobazam (to treat mental disorders)
Interactions are also possible with other drugs that are metabolised by the enzymes CYP3A4 and CYP2D6. These include, for example, calcium antagonists and beta blockers used to treat high blood pressure and heart disease, antihistamines, antiretroviral drugs, immunosuppressants, tricyclic antidepressants and other medications to lower cholesterol levels.
If you are taking one or more of these medications, you should only take CBD after consulting your doctor.
CBD SIDE EFFECTS OFTEN DUE TO POOR QUALITY PRODUCTS
In general, CBD is generally well tolerated by patients and adverse side effects are rare. However, the risk increases when using poor quality CBD products. Many commercially available products are contaminated with chemicals or do not contain the amounts of CBD promised on the packaging. Last but not least, you also run the risk that the product contains too much prohibited THC when you purchase from unreliable retailers.
In order to avoid unnecessary risks and unpleasant experiences with CBD, you should make sure that you only use products whose quality has been tested by a third-party lab. It is also recommended to purchase CBD only from suppliers you trust.