How safe is CBD oil? 

The non-intoxicating cannabidiol (CBD) is experiencing a serious boom in the natural supplements market. 

BDS Analytics and Arcview Market Research estimate CBD sales — a market spanning industries from cosmetics, health products, food and beverage to pet products, skin care, and pharmaceuticals — will exceed $20 billion in the United States by 2024.

CBD, which is extracted from marijuana or hemp plants, is available in oil form for ingestion. But it is also now available in an increasing variety of edible forms that are made by infusing the oil into a desired food or beverage – including gummies, honey, cookies, and coffee. 

CBD, which is extracted from marijuana or hemp plants, is available in oil form for ingestion as a supplement.
Photo by: Gina Coleman/Weedmaps

And ingestion isn't the only method of delivery, either — topical salves, serums, lotions, and makeup are also part of the market flood. 

The supposed benefits of CBD oil are as wide and varied as its delivery methods, such as a pain reliever, acne reducer, anxiety alleviator, and an aid in helping with neurological disorders. 

Because cannabis remains illegal on the federal level, the amount of research available for marijuana and its components, including CBD, is limited. However, there are certainly areas of health and medicine where CBD shows promise.

What the research shows

In June 2018 the FDA announced its approval of CBD pharmaceutical Epidiolex to treat seizures associated with two rare and severe types of epilepsy — Lennox-Gastaut syndrome and Dravet syndrome — in patients age two and older. It's the first FDA-approved drug to contain a purified CBD extract from the cannabis plant.

Stress, which can contribute to conditions including high blood pressure, heart disease, and diabetes, is another area in which CBD oil may provide some benefit. In a study published in 2017 in the journal “Frontiers in Pharmacology,” researchers from the Ribeirão Preto Medical School at the University of São Paulo in Brazil examined the anxiety-reducing potential of CBD in healthy human test subjects. 

Sixty men and women between ages 18 and 35 were randomly assigned to five groups that each received either a placebo, the sedative clonazepam (1 milligram), or CBD (in 100, 300, and 900 milligram doses, all orally administered). Each test subject was required to speak in front of a group formed by the remaining subjects and was measured for anxiety and sedation, blood pressure, and heart rate. Study participants receiving clonazepam showed a significant reduction in anxiety scores compared with the placebo group during the speech phase. In the phase following the speech, both the clonazepam and 300 milligram CBD groups, but not the 100 or 900 milligram CBD groups, exhibited reduced anxiety. The clonazepam showed a more sedative effect than CBD in 300 or 900 milligram doses, and led to a smaller increase in systolic and diastolic blood pressure than CBD in the 300 milligram dosage. 

Pain and inflammation reduction is another area of interest for researchers and the general public. Arthritis sufferers are among the many groups keeping a watchful eye on the potential benefits of CBD oil for pain. 

Arthritis sufferers are among the many groups keeping a watchful eye on the potential benefits of CBD oil for pain.
Photo by: Gina Coleman/Weedmaps

In one study published in October 2015 in the “European Journal of Pain,” researchers from the University of Kentucky College of Pharmacy found that topical CBD could potentially provide relief of arthritis pain, by examining pain-related behaviors and inflammation in rats. 

Another study, published in “BMC Complementary and Alternative Medicine”in January 2019, looked at the effectiveness of self-care techniques in pain reduction for Australian women with endometriosis. Survey participants self-reported that cannabis and hemp/CBD oil were the most highly rated in pain reduction, along with heat and dietary changes. 

Licensed herbalist and acupuncturist Katie Stem, who is CEO of Peak Extracts, an extraction company and edibles producer in Oregon, says “There is a large amount of scientific evidence that CBD is both neuroprotective and anti-inflammatory, meaning that it could be useful for treating a vast range of conditions involving pain, neurological disease, autoimmune disease and anything involving inflammation.” Indeed, a 2018 review of existing research published in “Surgical Neurology International” found that CBD appeared to reduce brain damage and improve the formation of new neurons in the brains of animal models as well as preserving circulation in the brain during so-called mini-strokes and reducing brain inflammation in humans. The review also pointed to CBD's low toxicity and lower chances of adverse side effects in humans. 

“Because the endocannabinoid system regulates a large number of physiological processes, and CBD both stimulates and modulates ECS activity, there are a huge number of avenues to explore in research for its possible therapeutic impact,” Stem concluded. 

What are the risks?

According to Epidiolex's prescribing information, the risks for patients using Epidiolex include elevated liver enzymes, which may mean liver damage, especially for those taking certain anti-seizure medications and higher doses of Epidiolex. Dosing adjustments are recommended for those with moderate or severe liver impairment. Other potential adverse reactions include drowsiness, decreased appetite, diarrhea, fatigue, weakness, rash, insomnia, and infections. 

Potential adverse reactions include drowsiness, decreased appetite, diarrhea, fatigue, weakness, rash, insomnia, and infections. 
Photo by: Gina Coleman/Weedmaps

Drug interactions are another possibility. According to an article in Harvard Medical School's “Harvard Health Publishing” by Dr. Peter Grinspoon, “CBD can increase the level in your blood of the blood thinner Coumadin, and it can raise levels of certain other medications in your blood.” 

Dr. Joe Goldstrich, a retired cardiologist who is now on the board of the Society of Cannabis Clinicians, said, “The most medically significant potential for adverse reactions from cannabidiol use comes from its ability to block various enzymes in the liver's cytochrome P450 system.”

Stem said that though “there is a possibility of drug interactions, there just isn't enough data yet to make a definitive statement about the particulars. If you are taking any medications, it's important to discuss CBD with your physician before experimentation.”

Another issue when it comes to possible risks of CBD oil is quality control. The FDA has been posting its warning letters to companies since 2015 for marketing unapproved new drugs purportedly containing CBD. 

“As part of these actions, FDA has tested the chemical content of cannabinoid compounds in some of the products, and many were found to not contain the levels of CBD they claimed to contain,” according to the FDA website. 

Pesticide contamination is another potential problem. 

“Pesticide, heavy metal, and potency lab testing are a must for any product, as there are many out on the market that are contaminated or underdosed,” Stem said. “I believe it to be safer than many supplements on the market, but since there is a risk of pesticide contamination, I believe that it should be tested aggressively and purchased from a reputable source.”

So, is CBD oil safe?

Some physicians and experts believe it is. There is clinical evidence of its low toxicity and low incidences of side effects. Its non-intoxicating nature limits its potential for abuse. However, due to its effects on the liver, anyone on prescription medication should consult a physician before beginning a CBD regimen. 

Major contributions from Dr. Adie Rae.

Was this article helpful? Give Feedback

has been subscribed!

The information contained in this site is provided for informational purposes only, and should not be construed as medical or legal advice. This page was last updated on June 20, 2022.