Clinical research has shown that CBD oil can trigger side effects. Severity and type can vary from one person to the next.
There is some evidence that CBD interacts with seizure medications such as Onfi (clobazam) and boosts their concentration in the blood. Further research is needed.
CBD oil may reduce the risk of heart disease by alleviating hypertension (high blood pressure) in certain people, suggests a 2017 study in JCI Insight.
Possible Side Effects
Proponents claim that CBD oil can treat a wide variety of health problems, including:
To use CBD oil, place one or more drops under the tongue and hold the dose there for 30 to 60 seconds without swallowing. Capsules and gummies are easier to dose, although they tend to be more costly. CBD sublingual sprays are available as well.
To determine an exact dose of CBD, remember that each drop of oil equals 0.05 mL of fluid. This means that a 30-mL bottle of CBD oil will have roughly 600 drops. If the concentration of the tincture is 1,500 mg/mL, one drop would contain 2.5 mg of CBD (1,500 mg ÷ 600 drops = 2.5 mg).
Part of this response could be explained by the way that CBD acts in the brain. In low doses, CBD may act as an agonist to several receptor sites, meaning it acts similarly to surrounding molecules that normally bind to the receptor, enhancing the signalling of those receptor sites. At higher doses, however, too much activity at the receptor site can lead to an opposite effect, negating the beneficial effects of CBD.
Some people may get diarrhea or liver problems [when using CBD]. This is dependent on the individual and their medical history, so monitoring is important,” says Dr. Matharu-Daley.
“If the CBD is from a reputable source and one that has been inspected by a third-party independent lab, the content of CBD is more reliable,” notes Dr. Matharu-Daley. “The CBD should be organically grown, free of pesticides and heavy metals, and not sourced in food which can affect absorption. Generally, CBD is safe and side effects are few at low doses.”
Also known as “cotton mouth,” CBD can potentially cause your mouth and eyes to feel very dry, notes Dr. Brent A. Bauer via Mayo Clinic. Though this side effect is more likely to occur with THC, it can happen with CBD, as well.
“Since discovering the endocannabinoid system (ECS) in the body in the 1990s, CBD has been researched more extensively. The ECS is a central regulatory system restoring normal balance and homeostasis in a range of human physiologic systems throughout the body and brain and has cannabinoid receptors and chemicals in its function,” explains Dr. Matharu-Daley.
She adds, “[Another difference is that] CBD is derived from hemp and has been classified as a legal substance. Hemp has <0.3% THC. Conversely, cannabis plants such as marijuana are grown to have much higher levels of THC and are still illegal according to the FDA, although individual states vary as to their use.”
A review of clinical trials of the effect of cannabinoids on sleep suggested that cannabinoids could improve sleep quality, decrease sleep disturbances, and decrease the time it takes to fall asleep. However there were many limiting factors such as a small number of people studied and they evaluated sleep within studies of other illnesses.
The body also produces natural cannabinoids, called endocannabinoids. Cannabinoids act on cannabinoid receptors.
CBD is the primary cannabinoid in hemp. It has various healing properties. For example, it seems to lessen inflammation, the body’s response to illness or injury. In this way, it may be helpful in treating many different diseases.
Does Topical CBD Help with Pain?
Two ways to use CBD are by mouth (oral) and applied to the skin (topical).
Many studies of CBD, including its side effects, are in their early stages. Most people tolerate CBD well.
An app was used to measure changes in insomnia in over 400 people taking medical cannabis. The average symptom severity was reduced by 4.5 points on a 10-point scale, a significant improvement in insomnia.
A review and meta-analysis of 8 studies with low-quality evidence of cannabis-based medicines found that they were better at reducing sleep problems compared to inactive medicines (placebo).