Is it safe to drive on CBD? Scientists are worried about 1 side effect
The FDA cautions weary travelers about driving on CBD.
The world of CBD is expanding. Now that it comes in special edition Carls Jr. Burgers, gummies, seltzers, and sports products, evangelists behind the now-famous cannabinoid are finding uses for it in almost any situation: from post-workout relaxation to a mid-afternoon productivity jolt. Meanwhile, the Food and Drug Administration (FDA) has hinted that there are some places that CBD’s effects may not translate well вЂ” starting with behind the wheel of your car, even if it can’t even get you high.
Tetrahydrocannabinol (THC) is the chemical that’s responsible for marijuana’s characteristic high. Though cannabidiol (CBD) is also an active ingredient of cannabis, its effects on the brain and body are far different, raging from anti-epileptic qualities to potential anti-anxiety effects.
It’s increasingly obvious that THC and driving don’t mix: A 2018 research letter published in Jama Internal Medicine revealed that “holiday” 4/20 was linked to a 12 percent increase in fatal car crashes (though that study wasn’t able to control for potential alcohol use). But even among sober drivers, a January 2020 study linked chronic THC use to impaired driving skills вЂ” especially in teens who started smoking weed before the age of 16.
How CBD affects driving though, is more of an open question, going by a press release issued by the FDA in December 2019, aimed at weary holiday travelers. The agency cautioned that drivers should “use caution if planning on operating a motor vehicle after consuming any CBD products.” That warning was based on the assertion that CBD can cause drowsiness, sedation, or lethargy, the release states.
There are, for now, very few studies investigating how CBD may impact driving. However, Thomas Arkwell, a Ph.D. candidate at the University of Sydney, did investigate the relationship between CBD, THC, and driving in a 2019 paper published in the journal Psychopharmacology. He tells Inverse that CBD use is unlikely to impair driving, but scientists are still examining its effects, because “we don’t know for sure.”
“There is some evidence to suggests that CBD may cause mild sedation at high doses, and this could translate into subtle driving impairment,” Arkell says.
The science of drowsy driving
The concern over CBD’s effects on driving performance has little to do with its status as a cannabinoid. Instead, the concern links back to the extract’s proposed mild sedative effect. That effect has anecdotal backing (about 10 percent of Americans who reported trying CBD used it to try to improve sleep, a 2019 Consumer Reports survey notes). That sedative effect is also noted in several previous studies вЂ” but, Arkell notes, those were only documented when it was taken in high doses.
In contrast to the sparse research on CBD and driving, the research on well-known drowsy drugs, like sleep aids, and their effects on driving performance are clear. Take one 2015 review published in The American Journal of Public Health. That study analyzed the collision records of 404,171 adults who reported using trazodone (an anti-depressant), temazepam (a prescription sleep-aid) and zolpidem (usually sold as Ambien). The use of any of those three drugs increased the chances of a car accident, but the results were particularly striking for Ambien users.
Ambien-users risk of accident doubled compared to people who didn’t use the drug. The authors likened the impairment to having a blood alcohol level of between .06% and .11% percent вЂ” close to or over the legal limit to drive.
That said, there are big differences between a drug like Ambien, which is intended to knock you out at night and CBD, where the sedative effects, if seen at all, are often described as mild. Still, even non-drug induced drowsy driving is a major concern for regulatory agencies like the CDC.
The National Highway Traffic Association notes that 795 people died as a result of drowsy driving during 2017, and the CDC estimates that lack of sleep and driving alone was responsible for 72,000 injuries in 2013.
“We will have the answer to this very soon!”
Even a minor connection between CBD and drowsiness, says Arkell, is enough to justify looking into whether CBD might be on thing that makes you just a little bit less alert while on the road. That’s the direction his research is currently taking, though there’s not a clear answer yet.
“We are also nearing the end of an on-road driving study which is looking at the effects of THC and CBD, both alone and in combination, on real-world driving performance,” Arkell says. “So we will have the answer to this very soon!”
Myths about CBD and driving
If they exist, CBD’s effects on driving are likely subtle. Still, Arkell explains that one major myth about CBD and driving endures: the idea that CBD can actually counteract THC’s known negative effects. It’s true that research suggests that CBD can help offset the anxiety-inducing effects of THC. But Arkell is concerned that this research may be being mistranslated.
“There is a lot of misinformation on the internet about how CBD can modulate the effects of THC, and I worry that this information might be passed on to unsuspecting medical cannabis patients and consumers,” he says.
“There is a lot of misinformation on the internet about how CBD can modulate the effects of THC.”
Luckily, Arkell’s research, which involved a simulated driving test and some THC and CBD-laced vapes, provides some clarification.
In his study, 14 participants vaped 125 milligrams of liquid that was either THC-heavy or equal parts CBD and THC. Then, each participant played a simulated driving game where they had to follow GPS instructions on highway or rural roads. When participants vaped both THC and CBD in equal concentrations, they tended to swerve more during their driving tests and reported feeling impaired up to four hours later.
“Our research suggests that CBD does not reduce the impairing effects of THC, at least with respect to driving, so itвЂ™s important that people are aware of this and can make their own decisions accordingly,” Arkell adds.
Importantly, this study didn’t include a CBD-only condition, which the authors say was because vaping CBD alone is “uncommon in the real world” (though this is likely changing). However, the team did find that when CBD and THC were administered in equal doses there were higher traces of THC in the participant’s blood compared to when they got THC alone, suggesting that the interplay between CBD, THC, and driving could be of concern going forward.
Still, the kind of CBD that we might ingest and think nothing about вЂ” like seltzer or a gummy вЂ” probably doesn’t help your performance on the road (especially if you’re already impaired). As far as the consequences of CBD use and driving go, if they’re out there, ongoing work is looking to illuminate them.
In the meantime, if you’re worried about being drowsy on the road, a good night’s sleep is probably the best place to start.
The FDA cautions weary travelers about driving on CBD.
CBD Products May Not Be as Intoxicant-Free As Drivers Think, DOT Warns
The feds warn commercial drivers that it could show up on drug tests, saying many CBD products do contain some THC, the psychoactive part of marijuana, even if it’s not supposed to be there.
- While CBD is legal, the U.S. Department of Transportation has warned commercial drivers that it can show up in a drug test.
- CBD products are popular and only getting more so, but even though they are labeled as containing no THC, some may actually contain a little of the psychoactive ingredient.
- “Innocent ingestion or false labeling is not a valid medical excuse for a [positive] urine drug test,” the DOT said.
Driving while intoxicated is obviously illegal and dangerous. We’re not here to debate that. But there are legal limits (different in different jurisdictions) for how much alcohol someone can have in their system and still be considered okay to drive. When it comes to THC, the main psychoactive part of marijuana, it’s a big new world out there if you’re a federal regulator.
Some drivers should be paying attention to what the Department of Transportation is doing to figure this all out. Spoiler alert: commercial drivers might want to lay off the CBD.
You’ve probably seen cannabidiol (CBD) oils, or other CBD products, being sold at gas stations and grocery stores, because they are pretty much everywhere these days. The claim is that these products can relieve pains and other issues, like anxiety. The Brightfield Group, a research firm focused on the CBD and cannabis industries, said last year that the CBD market is on track to grow to $23.7 billion through 2023. And that means more people are taking CBD products, and so more people are driving after they’ve done so.
Of course, CBD products are not supposed to get you high in any way, but that doesn’t mean that a drug test won’t pick up CBD artifacts. And, as of right now, the DOT is taking a zero-tolerance approach toward drivers of commercial motor vehicles (CMVs) who test positive. Actually, it’s more like a 0.3 percent tolerance. That’s because CBD products are required to use cannabis that contains less than 0.3 percent of THC on a dry-weight basis (in other words, the kind that will get you as high as smoking, say, oak leaves) based on the 2018 Farm Bill. That bill changed the definition of hemp so that it was not classified as marijuana, THC, and it also legalized cannabinoids (CBD) if they were non-psychotropic. That’s why, today, CBD companies highlight this low number as a way to make you feel safe about taking it.
AnandaHemp, which sells CBD oils, warns that taking their CBD oils may make you sleepy, but claims that “you should be able to drive after taking CBD Oil or Hemp Oil. Our CBD Oils contain less than 0.3 percent of THC and will have no psychoactive effects on your body.”
But during a virtual meeting of the DOT’s Motor Carrier Safety Advisory Committee on July 13, Office of Drug and Alcohol Policy and Compliance policy advisor Sue Lenhard updated the public on the agency’s rules, and they are full of warnings for commercial drivers. “Some CBD products are being marketed with unproven medical claims and are of unknown quality and CBD & THC quantity,” she wrote. The DOT also maintains that “innocent ingestion or false labeling is not a valid medical excuse for a urine drug test at THCA confirmatory levels of 15ng/mL.” The trade publication Transport Topics reported on the meeting in a story titled, “Truck Drivers Should Beware of CBD.”
The Food and Drug Administration does not currently certify the levels of THC in CBD products, so the labels on CBD products could be misleading. In fact, the government tested 84 CBD products from 31 companies in 2017 and found that 21 of them were mislabeled and that a higher-than-advertised THC content was found in 18 samples.
Testing positive for THC in this case does not mean that a driver would be considered intoxicated—rather that they have, at some point in the recent past, ingested enough THC for it to show up on the test. And, if you’re considered a “safety-sensitive employee,” which includes school bus drivers, truck drivers, and transit vehicle operators, then a positive result could harm your employment status, with the DOT warning that the information will be sent to the DOT’s Drug and Alcohol Clearninghouse and remain on file for five years and that an employee may have to go through a Substance Abuse Professional program, as well as other return-to-duty drug tests and observations. Just a heads up.
Studies show many CBD products not so labeled actually contain THC, the psychoactive part of marijuana, and it could show up on commercial drivers' drug tests.