explainers

Your Questions About CBD, Answered

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CBD is in everything now: skin care, food, and regrettably, even leggings. People have lauded its effectiveness for treating a whole host of issues, from helping anxiety to managing pain.

But is CBD an all-powerful, magical healing ingredient, or is it just a placebo? Or something in the middle? There is still plenty of research left to be done. “The enthusiasm for CBD has clearly outpaced the hard-core scientific evidence for what it actually does,” says Peter Grinspoon, instructor at Harvard Medical School and a board member for Doctors for Cannabis Regulation. “A lot of the studies we have are based on animal studies, and many fewer are based on human studies.”

Still, there’s plenty that we do know about CBD. Here’s the be-all, end-all guide to all of your questions about CBD, answered by Grinspoon.

What exactly is CBD?

CBD, or cannabidiol, is one of the cannabinoids found in cannabis. Grinspoon explains that THC and CBD are both cannabinoids. CBD can come from marijuana or hemp, or it can be isolated in a laboratory. Research has been slow on CBD, since it’s still under Schedule One of the Controlled Substance Act. “Even though CBD has no addictive or abuse liability — you couldn’t get high from it or have any fun with it if you wanted to — it’s still very hard to do research on it,” says Grinspoon.

What’s the difference between CBD and THC?

On a molecular level, the two cannabinoids are pretty similar. But when it comes to how they work, they couldn’t be more different. “THC causes a euphoria and a high,” says Grinspoon. “CBD works more indirectly. CBD does not cause the high, it’s nonintoxicating.”

Is there a difference between hemp and marijuana?

“There’s one simple difference,” explains Grinspoon. “Hemp is defined as having less than .3 percent of THC. Literally, that’s the only difference.”

What are the effects of CBD?

“In animal studies and some human studies, there is evidence that THC helps with chronic pain, anxiety, insomnia, and addiction, it’s an antimicrobial, and it helps with childhood epilepsy. The most definitive research is for childhood epilepsy,” says Grinspoon. In a placebo-controlled study in humans, CBD was also found to be an effective tool to ease performance anxiety for public speaking.

Grinspoon cautions that just because something works in an animal study doesn’t mean it will work for humans. And it’s often hard to tell why human subjects report things working. “Anecdotally, there’s an extraordinary amount of evidence for CBD helping with anxiety, but you don’t know how much of that’s placebo and how much is actually the CBD,” says Grinspoon. “It’s very hard to tell, but it’s hard to imagine that all of this could be placebo.”

Is it a good option for anxiety or pain management?

Grinspoon thinks it’s worth a try. There are a few things to consider when buying CBD. First of all, it can get expensive. The doses also tend to be low compared to what the animal studies have found to be effective. The biggest concern when buying CBD, though, is that it’s not a regulated substance. “You have to do your due diligence and make sure that you know the place you get it from has outside independent laboratory testing, so you’re actually getting CBD, and only CBD, and the right amount of CBD.”

Are there any potential side effects?

Grinspoon says that CBD could potentially cause GI upset and diarrhea. Make sure that your doctor knows you’re taking CBD if you’re on a blood thinner or any other medication, because CBD interacts with medications the same way that grapefruit juice does. A study also found that young mice given high amounts of CBD showed liver toxicity.

In general, Grinspoon thinks CBD is a low-risk, safe option for things like anxiety and pain management. And again, do your research beforehand to make sure that you’re taking pure CBD, with no THC or added contaminants in it. “The last thing you want is THC when you’re not expecting it, Grinspoon says. “You could drive home, that could be a disaster.” And don’t take too much — Healthline.com suggests that therapeutic CBD doses range from 0.5 mg/kg per day to 20 mg/kg per day.

Does CBD show up on a drug test?

Unfortunately, maybe. It all depends on how sensitive the drug test is. Remember, hemp has .3 percent or less THC in it, but that doesn’t mean it’s not there. And marijuana-derived CBD has slightly more THC in it. “Depending on how concentrated your urine is, how much you’ve used, it could show up on a drug test as positive for THC.” If testing for THC would be detrimental to your job, CBD might not be your best bet.

Can you take CBD if you’re pregnant or breastfeeding?

No. The FDA recently warned against this. There is a potential for CBD to be contaminated with THC. CBD can also be transferred via breast milk. They also point to a study which alleges that high amounts of CBD in pregnant test animals have caused issues in the reproductive system of “developing male fetuses.”

What’s the best method to take CBD?

“Certainly not the CBD bra or the CBD pillowcase,” says Grinspoon. He recommends pills, gummies, tinctures, or capsules. And if recent news hasn’t already convinced you, you should definitely skip CBD vape pens.

What about Instagram-worthy methods, like CBD lattes?

Save the $10 you’d spend. Not only will it probably be a very low dose of CBD, but you also have no way of knowing what you’re getting. “I know it’s kind of fun, ‘Hey, let’s get some CBD,’ but who knows what’s actually in it,” warns Grinspoon. “If it’s actually CBD, that doesn’t seem like the most consistent, reliable way to get CBD.”

Has the FDA approved any CBD products?

None, except one prescription medicine (Epidiolex) used to treat seizures in children. In general, the FDA’s standpoint is that there needs to be more testing about the efficacy of CBD, and there are lots of unanswered questions about its science and safety.

Is CBD legal?

It’s complicated. “Legality of CBD is improving, but it’s still kind of confusing and people have to be careful and check the legality before they sell it, travel with it, stuff like that,” says Grinspoon. “It’s not legal completely, unrestrictedly in all the states. You just have to be careful and check the legality so you don’t get in trouble.”

Is CBD useful in skin care?

Sort of. The body has two CBD receptors, conveniently named CB1 and CB2. When applied topically, CBD interacts with these receptors to create an anti-inflammatory response. This is promising for inflammatory skin conditions like psoriasis or eczema. Early studies (which are small in size), suggest CBD can help with decreasing itchiness and general quality of life for those skin types.

Your Questions About CBD, Answered