CBD Side Effects

What Are The Side Effects of CBD?

As cannabidiol becomes increasingly researched and better understood, it’s very apparent that it has several mechanisms of action that are similar to the mechanisms of many other legend drugs. Not only is CBD completely natural as a cannabinoid, but it carries few side effects compared to most pharmaceutical drugs.

Overview of CBD Side Effects

Some side effects of CBD have been reported, though most are caused by abnormally high dosages. In general, patients have reported three main side effects after taking CBD: lightheadedness, mild bouts of diarrhea, changes in appetite, dry mouth, transient hypotension, somnolence, and slight increases in liver enzymes (transaminases) with very high doses, on the order of 3000mg for a person weight 70kg. Read more about each of these side-effects:

Dry mouth, or “cotton mouth” as it is commonly known, is a characteristic side effect of most cannabinoids. However, dry mouth will only make you thirsty, and it is highly unlikely you’ll become dehydrated.

Although diarrhea and increased gastrointestinal motility is commonly reported with CBD, it is most likely caused by the carrier oil in which most CBD products are delivered. 

Changes in appetite, most commonly a decrease thereof, are associated with cannabidiol in a dose-dependent manner. Although a decrease in appetite may occur, surprisingly, there has been no evidence linking cannabidiol to weight-loss.

Small drops in blood pressure, which is usually a result of very high doses, have been known to occur after administration, followed by a rapid stabilization. The cause is unknown but there have been no adverse events resulting from hypotension associated with the use of cannabidiol.

Like most anti-epileptic drugs, cannabidiol is associated with mild to moderate non-dose-dependent drowsiness. However, due to its nonselective agonist activity at adenosine receptors, it has also been shown to induce wakefulness in some cases.

Transaminase elevations to above 3 times the normal upper limit occur in about 1 in 5 patients taking Epidiolex®. These elevations typically arose within 2 months of the commencement of treatment; they were transient, mild or moderate in severity, and not associated with any symptoms, to include jaundice.

Furthermore, there have been no reports of liver injury related to the use of cannabidiol, and all cases of elevated transaminase levels were associated with concomitant administration of valproate or another anti-epileptic drug.

As is common with many antiepileptic drugs, Epidiolex® (CBD) was reported to cause lightheadedness in a small portion of subjects in two of the four clinical trials conducted by GW Pharmaceuticals®

Though the above side effects are known to be characteristic of CBD, it is important to note that only a small subset of patients (around 20%) have reported that they occur at all, and that they are infrequent and/or mild to moderate in degree. Furthermore, in all  clinical, randomized, double-blind, placebo-controlled clinical studies conducted regarding CBD in human subjects, there have never been severe or serious adverse events reported, including in all of the trials for Epidiolex®. 


While healthcare providers need to be mindful of the possibility of these side-effects occurring in their patients who consume.

CBD has side effects

Within just one hour of watching an American television program, it’s likely you’ll see at least one ad for an antidepressant or heart medication, in which half of the ad spot is filled with a voiceover rapidly listing dozens of possible side effects to consider before taking the medication. In an in-depth study conducted in 2011, researchers and statisticians found that out of thousands of medication labels analyzed, the average pharmaceutical carries with it over 70 listed side effects.

Some of these side effects can be virtually undetectable by patients however, and many are listed for liability purposes in order for the manufacturers to avoid lawsuits. Even so, such a high number of side effects does make it difficult for medical professionals to find the best quality medication to fit their patients’ needs. Often times, additional prescriptions are required to combat the side-effects of the first drug.

As an organic chemical produced enzymatically in nature, rather than chemically in a lab, CBD already passes some basic toxicity tests; hoops through which many chemotherapeutic agents could not jump. Furthermore, CBD resembles hundreds of endogenous human metabolic byproducts, including many which act as hormones or signaling molecules in various body systems. By seamlessly integrating into this sophisticated biochemical dance, CBD acts with the body systems rather than on them; it is an allosteric modulator, not an agonist; it is an antioxidant, not a reducer; etc..

Lastly, CBD has more than 80 biological targets in the human system. Consider diphenhydramine, which is marketed as both Benadryl® and Sominex® for two different indications, both of which are considered side-effects of the other. The action of first-generation antihistamines as both sleeping aids and antiallergenics produces two effects concomitantly.