Recently, an FDA study raised concerns about the safety and efficacy of CBD oils, capsules, gummies and edibles. These products are ubiquitous in the United States, as well as many other nations. Bonni Goldstein MD warns that patients and doctors should not overstate the results of the FDA study published in JAMA Internal Medicine. Here is the summary of trial results, followed by Dr. Goldstein’s comments. The CEO and founder of GoldsteinWellness.comA free platform of medical cannabis education for licensed health care clinicians. Medical Director, Canna-Centers California.
Last year, scientists from the FDA’s Division of Applied Regulatory Science carried out a randomized double-blind placebo-controlled trial to assess how “low-dose CBD” affects liver function in a group of healthy middle-aged men and women. JAMA Internal Medicine published the results of this trial.
Over the course four weeks, 201 participants received oral CBD isolate at a dose of 5 mg/kg (approximately 2 mg/pound, which is the equivalent to 350 mg in a 154 lb individual), or a comparison placebo. In the report, CBD dosage administered to participants was described as “a typical dose that consumers might use.”
Although the majority of participants in the study were not affected, 5% showed elevated levels of aminotransferase (a liver enzyme), a marker for liver damage or inflammation. Women seemed to be at greater risk than men. The most severe liver disorders were also accompanied by signs of eosinophilia. This is an immune disorder that occurs when an excessive amount of a white blood cell known as eosinophils are produced in the body. All liver enzymes returned to normal levels within a week or two of ceasing CBD.
The elevated levels of liver enzymes was one of the main reasons for young patients with epilepsy to withdraw from clinical trials that used high doses Epidiolex (a pharmaceutical CBD isolate). In 14% of the participants who took anti-epileptic drugs concurrently, liver enzymes increased. This could be what caused adverse effects on liver.
In the absence of any other drug, the FDA has published the latest findings that “low-dose CBD” may still pose a threat to the liver. The FDA’s findings could have a significant impact on the health of many individuals who consume CBD supplements over-the-counter. According to various surveys in recent years, the majority of people in the U.S. have heard of CBD, and around 20% reported using CBD products in the past 12 months.
Dr. Bonni Goldstein replies:
I do not consider 350 mg CBD a low dose. I would like to know how researchers came up with this dose, because it is not representative of what the majority of adult CBD patients/consumers use, based on my personal experience. Most people who ask me for advice on CBD underdose. Additionally, the cost of 350 mg of CBD per day ranges from about $7 – $40 per day, so we are talking about $210 per month up to $1200 per month. This amount may not be too expensive for moderately to seriously ill children and adults, but it could prove prohibitive for those who use CBD for pain, sleep, or anxiety.
The drug used in this study was an isolator (which requires a much higher dosage than full-spectrum CBD products). The purified CBD studies (Epidiolex), as well as a few reports, have documented elevated liver enzymes.
My practice has thousands of full spectrum CBD users. Less than 10 of them have elevated liver enzymes. All of these patients were also taking either valproic or chemotherapy. Labs returned to normal in all cases after CBD doses were reduced or discontinued. No liver damage caused by CBD has been irreversible in my knowledge.
This study shows that clinicians should ask about the use of cannabinoids during appointments with patients, assess dosing levels and check liver function tests when indicated. Most clinicians are not familiar with cannabinoid-based pharmacology. If they read or hear this study, they may generalize, telling patients that CBD is harmful to the liver. They will miss the important nuances between full spectrum and isolate CBD, as well as the benefits of entourage effects, which allow for lower dosage.
Bonni Goldstein MD is CEO and cofounder of GoldsteinWellness.comThe Medical Director of Canna-Centers, and a platform that provides free educational materials on medical cannabis for healthcare professionals in the U.S.