MADDIE SOFIA, HOST:
You're listening to SHORT WAVE from NPR.
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SOFIA: Maddie Sofia here with NPR health correspondent Allison Aubrey. Hey, Allison.
ALLISON AUBREY, BYLINE: Hey, Maddie.
SOFIA: So today we're talking about a topic that a lot of people have questions about - CBD.
AUBREY: Yes. Cannabidiol - or CBD, as you say - it is compound found in the cannabis plant, so you find it in marijuana and hemp. And it has exploded in popularity. It is touted as an elixir that can do everything from relieve anxiety to help ease your aches and pains. You've heard about it. Right, Maddie?
SOFIA: Oh, yeah.
AUBREY: So there are a lot of companies, from big operations to mom and pop shops, selling it. I can tell you, having been in truck stops in rural Pennsylvania and on the freeway in Silicon Valley, no matter where you are in the country right now, you are likely seeing ads for CBD.
SOFIA: But here's the thing. Last week, the Food and Drug Administration came out with some fairly strong warnings.
AUBREY: Yes. Basically, they came out and they issued warning letters to 15 companies selling CBD products. And they're basically saying you are violating FDA policy. They say you are not allowed to market CBD products as a treatment for any condition or disease, you cannot sell it as a dietary supplement, and you may not put it in any foods that are fed to people or animals. Now, just because the FDA has - says this is not allowed does not mean that you'll stop seeing products marketed this way. And we'll get to that in a little bit.
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SOFIA: And the same day that they warned all those companies, the FDA also updated their consumer guidance for CBD, their what-you-need-to-know-about-CBD page, citing some pretty serious safety concerns.
AUBREY: It's a lot of warnings.
SOFIA: So today on the show, we're going to break down what the FDA says about CBD and how some of those warnings might be more valid than others.
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SOFIA: So Allison, give me the CBD 101.
AUBREY: Sure. Cannabidiol, or CBD for short, is a component of cannabis. That means it is extracted from the plant - pulled out of the plant. It does not contain the psychoactive component THC that we all know about that makes you high, but it still works on your brain in ways that scientists don't completely understand yet.
I have reported on studies that are currently evaluating CBD's potential role in curbing anxiety. There are federal grants, I should say, to evaluate whether CBD could be used as an alternative to opioids. But so far, there's only one FDA-approved CBD drug on the market. It's approved to treat very specific childhood epilepsy disorders.
SOFIA: So we have this weird situation. On one hand, everybody's using CBD; there's all this research going on. And then the FDA is saying, we can't conclude that CBD is safe.
AUBREY: Yes, you're right. It seems paradoxical. So let's step back a moment to give some context, make sense of this. Basically, CBD has been in what I would call regulatory limbo - I mean, big time. For a long time, the production of hemp was restricted. It was considered a controlled substance. Hemp and marijuana are varieties of the same plant - cannabis. Then last year, under pressure from Congress and hemp farmers, these restrictions were lifted as part of the 2018 Farm Bill. And the hemp industry said, alleluia - this is great.
But the FDA quickly stepped in and said, hey, wait a second here. We have regulatory authority over CBD, and there's a lot we still don't know. Remember - this compound kind of came out of nowhere. I mean - right? Had you heard of CBD three years ago?
SOFIA: Not really.
AUBREY: I mean, this year I wouldn't be surprised if it's one of the more popular items in Christmas stockings around the country.
SOFIA: So is it fair to say the FDA might have been a little bit caught off guard by this...
AUBREY: Yes.
SOFIA: ...By this boom of CBD?
AUBREY: That's right. And it's well within their purview to regulate it when it's used in foods or as a drug. But they say they just don't have a lot of data to go on yet. Right now the agency is in the midst of writing some specific rules to regulate. But before they do, they want to know that it's safe.
SOFIA: We should also point out that even though the FDA just said we can't say CBD is safe, the World Health Organization, another giant public health organization, put out a report last year saying CBD is generally well-tolerated and has a good, quote, "safety profile."
AUBREY: That's right. From what they've seen so far, the WHO is saying there can be some adverse effects from drug interactions. But there's no evidence of any public health-related problem associated with it is what they say. They point to the fact that several countries have modified their regulations to allow the use of CBD as a medicinal product. But again, the FDA - playing it safe, saying it needs more data. Now, one area where they say they need more is on the potential for liver damage from using CBD. And you've been looking into that, right?
SOFIA: Yeah. So that is actually one of the things the FDA warns people about in the What You Need to Know page.
AUBREY: OK.
SOFIA: I looked into it a bit, and some of this data came from when the FDA was reviewing the epilepsy medication that we've talked about. Basically, they found that taking CBD has the potential for damaging the liver. And that was very dose dependent, meaning most of the troubling results happened at higher doses.
AUBREY: And that makes sense.
SOFIA: Right. There's a good bit of data out there supporting this. And a lot of the serious damage was seen when people were taking other drugs that also impacted the liver.
AUBREY: And that brings us to another warning, which is potential drug interactions. Does CBD increase or decrease the effects of other medications you might be taking? Does it increase side effects? Basically, the FDA is saying they are concerned about the potential safety of taking other medications at the same time you're taking CBD when you're not being monitored by a health care professional.
SOFIA: And the most interesting warning they put out - to me, at least - was their mention of this potential for male reproductive toxicity.
AUBREY: (Laughter) OK.
SOFIA: Yeah. So the FDA warns that CBD led to decreased testicular size, messed with the growth of sperm and development and decreased circulating testosterone. But the thing is, Allison, all of this data came from animal studies, including a delightful study on sea urchins.
AUBREY: Sea urchins?
SOFIA: Yep.
AUBREY: OK.
SOFIA: And in one of those studies, they weren't even testing on actual animals - just cells isolated from animals.
AUBREY: OK.
SOFIA: And even the FDA acknowledges that stuff that happens in animals does not necessarily happen in humans. Right? And I asked the FDA for more information about this, and they sent me about 12 studies, and I looked at a good bit of them. And some of them used really high doses of CBD.
AUBREY: Like, how high?
SOFIA: Like, 10 times the maximum recommended dose for the FDA-approved CBD drug that we've already been talking about.
AUBREY: Whoa - which is already a high dose.
SOFIA: Right. And to be fair, doses researchers use in animals are sometimes more than they use in humans, but I saw some real variability in the studies. Some found differences in sperm and how they're moving around, how much there is. But another didn't. And it seems to depend maybe on the type of animals that were studied.
AUBREY: So a lot of inconsistencies here.
SOFIA: A little bit, yeah. And in one of the studies, they did show that CBD treatment led to a decrease in testosterone, but it was still within the normal physiological range.
AUBREY: So you think these studies might be a little weak?
SOFIA: More like the conclusions that the FDA is drawing from this group of studies - there weren't that many of them. And I find it odd that the FDA put out this kind of scary fertility warning based solely on animal studies.
AUBREY: Mmm. So those are the specific warnings...
SOFIA: Mmm hmm.
AUBREY: ...The FDA has mentioned here.
SOFIA: Right.
AUBREY: But they also say that they have some concerns about special populations...
SOFIA: Mmm hmm.
AUBREY: ...Like the elderly, children, pregnant women and also a very special population - our pets - our dogs, our cats. You see all kind of marketing around doggie CBD for your anxious pup. But the FDA says that they can't say whether this is safe or effective. They also want to look into the cumulative effects, meaning what happens if you are using multiple CBD products at one time.
SOFIA: This was my favorite government warning section.
AUBREY: OK. Why? Why?
SOFIA: They say - literally said, what happens if you eat food with CBD in it, use CBD-infused skin cream and take other CBD products on the same day?
AUBREY: I am sure there are people out there doing that, Maddie.
SOFIA: I mean, I know where they're going with it. But it read to me like, what could happen if you put it in your eyes, in your ears, in your mouth - and you rubbed it on your butt in the same day?
AUBREY: (Laughter).
SOFIA: What could happen, Allison? We don't know.
AUBREY: (Laughter) Ay ay ay (ph).
SOFIA: But - OK, real talk - Allison...
AUBREY: Yes.
SOFIA: ...You have been reporting on the FDA and FDA-related things for years. What are your feelings about all this?
AUBREY: You know, I think the FDA is in a tough spot here. I mean, these are fair warnings if you consider what they know and don't know. The agency is just trying to communicate that the CBD products haven't all been evaluated for safety or efficacy, meaning whether they work or not. And you know, the CBD you buy online or over the counter, depending on who made it, might not have the amount of CBD in it it says on the bottle.
SOFIA: Right.
AUBREY: It might not actually contain CBD. I mean, given the current state of regulation, you just can't be sure.
SOFIA: Or you know, there could be other stuff in there that you don't want. Right?
AUBREY: Well, this is the perennial problem with supplements. Right? I mean, the FDA has this dividing line between how it regulates prescription drugs and how it regulates supplements. When something's a prescription drug, there is a rigorous amount of testing that goes into it. Right? When something is regulated as a supplement - hmm, it's kind of a wait-and-watch situation. If something goes wrong, the FDA certainly has the power to take it off the market. But you often don't know what's in the products or if there might be contaminants in there. So there's always a buyer beware message when you're talking about things that you're buying off the shelf, like dietary supplements.
SOFIA: And so what do you think about, you know, from, like, the safety perspective?
AUBREY: You know, I really do think - it's interesting what the World Health Organization has said. I mean, they're basically saying, from what we've seen so far, the safety profile looks to us pretty good. I think one possible resolution to all of this, as the FDA weighs exactly how to regulate CBD - I mean, let's face it; CBD is not going away...
SOFIA: Right.
AUBREY: ...But I think there could be some tiered system. That's certainly something you hear the industry talking about. There could be high-dose products, which would be restricted and require a prescription, then low-dose products, like supplements or foods, which would be more widely available.
SOFIA: Makes sense. So the PR person that I talked to said the FDA will have more to say about CBD in the coming weeks. So we will be looking forward to another CBD update soon.
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SOFIA: NPR health correspondent Allison Aubrey, thanks for the chat.
AUBREY: All right. Thanks, Maddie.
SOFIA: Before we go, a reminder that if you're enjoying the show, do us a favor and rate and review it on Apple Podcasts or your podcast app of choice. That helps new people find the show. And if you've already left a review, thank you. You are a nice person. We appreciate you.
This episode was produced by Brent Baughman and edited by Viet Le. I'm Maddie Sofia, and we're back tomorrow with more SHORT WAVE from NPR.
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