When it comes to cannabinoids, there is one universal truth to keep in mind: Everyone Is Different
There are countless variables such as weight, diet, metabolism, genetics, environment, product consistency, and more that make a universally prescribed dosage an impossibility.
CBD has very few negative side effects and it doesn’t negatively interact with the parts of the brain responsible for breathing and heart rate.
However, with that being said, it is entirely possible to take too much CBD. For some people taking too high a dose of CBD can lead to drowsiness and lethargy. Other possible negative side effects include upset stomach and diarrhea. Fortunately, these cases are rare and it’s very easy to avoid too high a dose of CBD. Just carefully read the label of the product you are using and make sure to start with a low dose and slowly increase the dose only if you need to.
“Start low and go slow.”
In general, the FDA requires that all approved medicines have an established toxicity level, or what’s known as an LD50.
The LD50 (LD stands for “lethal dose”) of any given chemical compound is the amount that it would take to kill 50% of test subjects at a certain dose. The “test subjects” are typically female rats (according to the FDA females are more sensitive to toxic effects than males), though any animal species could hypothetically be used.
For instance, if 100 rats were given 1,000 mg of ibuprofen and the dose proved to be lethal for 50 of them, we could accurately say that the LD50 for ibuprofen was 1,000 mg (this is a very loose generalization, and is not the actual LD50 for ibuprofen).
To be clear, clinical trials for an FDA-approved medicine do not have to disclose an LD50 for the drug in question. There simply has to be clear pre-existing scientific evidence that establishes some form of toxicity for the compound.
As such, the recent approval of Epidiolex did not disclose a specific LD50 or a human toxicity level for CBD oil. However, multiple previous studies have attempted to determine such a level for both cannabidiol (CBD) and 9-tetrahydrocannabinol (THC).
How Much CBD Would it Take to Kill You?
The toxicity levels for CBD (otherwise known as cannabidiol, which is the active ingredient in Epidiolex) are, in fact, listed by the federal government’s Toxicology Data Network. Three separate LD50’s have been determined from three different studies, spanning more than 70 years:
In 1946, the LD50 for cannabidiol in dogs was determined to be greater than 254 mg per kg of body weight, when administered intravenously.
In 1975, an LD50 was established in mice at 50mg per kg of body weight, when administered intravenously.
In 1981, a report in Toxicology and Applied Pharmaocology show the LD50 for CBD to be 212 mg per kg of body weight when administered intravenously in monkeys.
More recently, a 2011 article in Current Drug Safety observed toxic levels of CBD in rhesus monkeys when administered orally. Doses over 200 mg per kg of body weight proved to be fatal in some monkeys by way of respiratory arrest and cardiac failure, while 300 mg per kg of body weight resulted in “rapid death.”
For reference, consider a relatively “average sized” human at 75 kg (approx. 165 lbs). By these numbers, it would take roughly 18,750 mg (18.75 g) of CBD consumed within a very short amount of time to result in any potentially fatal effects. Most typical CBD oil users consume no more than 100 mg of the compound — and that’s throughout the course of an entire day.
In one 2018 report in Toxicology Communications, an LD50 for “crude marijuana extract” in beagles (a species of dog) could not even be determined as doses greater than 3,000 mg per kg of body weight did not result in any fatalities.
The same was true for rhesus monkeys, wherein a dose of 5,000 mg per kg of body weight “failed to elicit any sign of toxicity.” Moreover, doses of up to 9,000 mg per kg of body weight in primates had “no significant toxicity effects.”
According to these figures, the report concluded an “estimated” LD50 for marijuana extract to be larger than 10,000 mg per kg of body weight in primates.
Finally, in a 2016 report prepared for the FDA’s “8-Factor Analysis on Cannabis,” the research organization Americans for Safe Access (ASA) claimed that there is currently no known LD50 for any form of cannabis in humans – including any of its major component extracts.
The report emphasized the fact that researchers have for years been attempting to determine a consistent LD50 rating for cannabis in animals, with unsuccessful results. One statement in the report claimed that “researchers have continuously been unable to give animals enough natural Cannabis to induce a death.”
By current ASA estimations, in fact, a marijuana smoker would have to consume 20,000 to 40,000 times the amount of cannabis contained in a standard marijuana cigarette (defined by the National Institute on Drug Abuse to be 0.9 g) in order to experience any potentially fatal consequences. For reference, this would be approximately 1,500 lbs of cannabis within a 15 minute period to induce a “theoretically lethal response.”
By comparison, it’s common knowledge that the nicotine content in a single pack of tobacco cigarettes is enough to kill most humans, if ingested all at once.
Marijuana advocates point out there are zero reported cases of marijuana-induced death. For comparison, opioids, which include prescription pain relievers and heroin, killed more than 28,000 Americans in 2014. Nearly 88,000 people die from alcohol-related causes every year, which makes alcohol the fourth leading preventable cause of the death in the US.