Public Health

Pieter Cohen, MD, explains dietary supplements & regulations


AMA's Moving Medicine video series amplifies physician voices and highlights developments and achievements throughout medicine.



In today’s episode of Moving Medicine, a discussion with Pieter Cohen, MD, associate professor at Harvard Medical School and an internist at Cambridge Health Alliance, about what physicians need to know about dietary supplements to help keep their patients safe.

Learn more about MedWatch, the FDA’s medical product safety reporting program for health professionals, patients and consumers.


  • Pieter Cohen, MD, associate professor, Harvard Medical School; internist, Cambridge Health Alliance

Moving Medicine video series

AMA's Moving Medicine video series amplifies physician voices and highlights developments and achievements throughout medicine.

Unger: Hello, this is the American Medical Association's Moving Medicine video and podcast. Today, we're talking to Dr. Peter Cohen, an associate professor at Harvard Medical School and an internist at Cambridge Health Alliance, about what physicians need to know about dietary supplements to help keep patients safe. He's calling in from Brookline, Massachusetts, I'm Todd Unger, AMA's chief experience officer in Chicago.

Dr. Cohen, dietary supplementation regulations been an issue for a long time way before the pandemic but how did the pandemic exacerbate the issue?

Dr. Cohen: Well, during the pandemic, Todd, there's been a bunch of changes obviously to all of our lives. And some of those have had dramatic effects on sales of supplements and the use of supplements. Of course, one is that during the earlier months of the pandemic, during the lockdown, it was hard to access care. So the approach to self-medicating—especially, one, where you could purchase something right off of Amazon, have it delivered to your house—became extremely attractive, even more so than before. The other thing was that the ability of supplements to advertise themselves as preventive or treatment or immune boosters, that sort of ability, that option in the lot, created a lot of opportunities for marketing these products for Americans who were worried about their health during these very difficult times.

Unger: Yeah. We've seen that that issue with immune boosters in relation to colds and all sorts of other stuff. I think a lot of people think that supplements are carefully regulated. Can you explain exactly how they're regulated, if at all?

Dr. Cohen: Yeah, so they certainly are regulated. The FDA is responsible for regulating dietary supplements. We might think of them because they're health products as being a subcategory of medication. But in fact, the FDA regulates them as a subcategory of food. This has huge consequences for the whole category of dietary supplements, from vitamins, minerals, probiotics and all sorts of new ingredients. And what it means is that the manufacturer can introduce anything into the market that they believe is safe. And the FDA's job is to identify the products that are causing harm after they've been on the market and remove them from store shelves.

Unger: So that sounds like a place for possible reform. Can you talk about when you look at reform, what are kind of the elements of that?

Dr. Cohen: Well, the problem that we've had recently in recent years, especially, is that there's been an explosion of new ingredients. So it's not only that we're worried about the ingredients that are legal and permitted and supplements are historically used in supplements for many, many years. So there are many of these ingredients, these are individual compounds found in botanicals or other substances that can pose health risks. But nowadays we're seeing so many new innovations or brand new ingredients being introduced to supplements. Again, because the FDA isn't vetting these products before they show up on store shelves or on the internet, what happens is that they can pose unpredictable risks. So we need to work on reform. We need to work on ways to strengthen the FDA's ability to limit what comes on to the market, to have a safety gauge, to make sure that dangerous, potentially dangerous, products don't appear in store shelves. And when they do that, they can rapidly be taken off the market. So we're really going to need to see a lot of changes in order to deal with this very actively evolving health care products.

Unger: I'm curious, because obviously you're saying there has been an increase in these things. Is there capacity to do that kind of evaluation?

Dr. Cohen: That's a big challenge right now. So right now the FDA is completely overwhelmed. We don't even know how many products are out there. The estimates are that they're greater than 75,000 different dietary supplement products on the market. There is no way the FDA can get a handle on even what's out there, much less which of those are dangerous. Unless they are given new tools and we're probably going to need to see some significant changes to the laws made to give the agency the tools they need, but they'll also, of course, need the funding to operationalize it, to enforce the law.

Engaging nutrition and lifestyle CME

High-yield education from the nonprofit Gaples Institute on AMA Ed Hub™ will make nutrition and lifestyle science come alive in your clinical practice.

Unger: That's interesting because I'm very into fitness and health, obviously. And I do see a lot of this stuff show up in my Instagram feed. There's almost like a template that supplements like this will follow with a little video explaining kind of what the problem is and here's this new solution. Do you think that the marketers of these products are getting increasingly sophisticated in the digital age?

Dr. Cohen: Absolutely. And that's become another big problem nowadays with the internet and with social media is that even the very lax rules around promoting a supplement are being really pushed the limit to the point where their supplements are not ... Let me give you one example, a supplement is not supposed to be able to advertise as if it will help treat an illness or a disease. Unfortunately, because of the way social media is, it's very easy to link testimonials or little posts or tweets with things that will suggest to consumers and also micro target consumers who have diabetes, for example. And that this supplement might be useful to maintain healthy sugar levels. So if you're targeting an audience, a specific audience that the marketer knows very well likely has diabetes, then you're sending them these messages on social media or advertisements on social media that suggests that this supplement will maintain normal sugar levels. You can see that, that has all the appearance, a hundred percent of the appearance for the consumer, that this product will be able to treat their diabetes.

So basically the social media environment, it really permits the companies and manufacturers and others to promote these products as if they're treatments for disease. And that is particularly an insidious problem for patients.

Unger: Do you think that there's been an increase in, I'll call them just fountain-of-youth type approaches, kind of different supplements to keep people, quote, young?

Dr. Cohen: Oh, absolutely. Supplements are being promoted for just about everything today, but absolutely. If you look at any sphere you'll just be amazed whether or not it's preventing aging to improving cognitive function, be able to think better and also to a lot of things that are related to illnesses. So helping people deal with opioid addiction or how to relax with CBD without the effects of THC. These kinds of things are going on and each of these markets is just exploded. So it's really remarkable what's happening today in the supplement world—

Unger: So a question for you, what is a physician to do? I don't think this is something they cover necessarily in medical school, but I'm sure that physicians are probably fielding questions all the time from their patients about perspective effects of this. How do you advise physicians in this realm? What should they be watching for? What should they be telling their patients?

Dr. Cohen: Well, I think it's really important to just keep in mind that most of our patients are taking supplements. Whether or not they have told us about it or not, more than 50% of the U.S. adults are taking supplements. So it's important for us to recognize that most of our patients are using supplements. So we need to ask about it. Now, I think one perception that I had, because I also didn't learn about supplements when I was in medical school, was that these must be expensive placebos. Things that if a patient's taking it, fine, I don't need to worry about it because it's not going to affect their health, it's not going to affect their medications. What we've come to realize is that because the supplements are so often formulated much more closer to drugs, that it's incredibly important for us to pay attention to what our patients are taking. And to recognize that they might be causing direct, immediate effects on our patients.

So it's really important to have an open mind with our patients and being nonjudgmental and talking about supplements because we come in kind of like, "Oh, you're not taking any weight supplements, are you?" Where they're going to clam up and not share with us what's going on. So I really encourage docs to say, "A lot of my patients are struggling with weight, have chosen to try some weight loss supplements. Have you tried any?" So I really liked to, to try and encourage open conversation, find out what people are taking. Because once you find out about that and you learn about what the patient's taking, it might be affecting their immediate health. It might be contributing to palpitations or panic attacks, or more seriously something a serious as hepatitis or even a stroke. So it's these open minded conversations, taking a look at the labels together with our patients, reading up on it. Which is really what I recommend.

Unger: It's interesting because when you think about, say the last doctor visit I had, they're very particular about going through all the medications you're on. I don't think there's really a question in the HR, talk about your supplements that might not come up. But you are suggesting physician kind of check into that in a nonjudgmental way. Are there any kind of areas, you mentioned supplements about weight, I'm sure sleep disorders, things like that. Are there any other kind of particular areas that you would probe on?

Dr. Cohen: Well, I think it depends on what your patients seeing you for. So I think if someone's struggling with something for a while, I'd ask, "Have you tried anything over the counter for that?" Oftentimes when our patients respond to that, they'll just be thinking about over-the-counter medications, of course like ibuprofen or acetaminophen. So you really have to ask the next question, "Oh yeah, have you tried anything else?" Things are sold as supplements rather than their health products for that. So that's one thing to realize if you've asked patients what they have tried for it that might not cover it, they might be thinking over-the-counter medications is what you're asking about. Because oftentimes sort of in their mind, they're placing supplements in something that is not important for us to know about, doctors to know about. It's just something that I'm taking on my own. So it's important to let your patients know that we want to know about that, it is important and these can all interact.

I would say if I had a healthy person though, who didn't have any concerns, I guess my number one in terms of area to ask about would be in terms of sports supplements. That's because a lot of really healthy patients who are exercising, the highest risk category supplements they would be likely to try would be sports supplements. So I might say, "Oh yeah, with my patients who exercise regularly, they often are trying to take some pills or powder to enhance their workouts. Have you tried any or are you taking any?" And that conversation might some interesting opportunities to learn about what our patients are taking and discuss with them some of the health issues.

There is one thing, Todd, I do want to mention that it's very important once we do start these conversations with our patients and we believe that the supplement might've harmed our individual patients. So let's say it turns out that a patient developed a hyperthyroidism, only after starting a supplement and you stop the supplement and went away. Well, those reports really should be reported to the FDA. And the reason is that the FDA is relying on physicians to just spontaneously report what they're seeing in clinic in the hospital, in ED. So I can't emphasize enough how important it is to go to the FDA, go to MedWatch and for us to submit those reports.

Unger: Is that where a physician would do that? That site? Or how would they report that?

Dr. Cohen: Right. So it's the same process that we would have report for prescription medications. The thing is, most of us don't spend our time going to MedWatch and reporting side effects to prescription medications because these are side effects or adverse events that are well known and well documented ledger. And we don't feel obliged to because the FDA knows that aspirin can cause bleeding. So we're not going to be reporting that. With dietary supplements, it's different. If you have a product and a patient started taking your product and develop a stroke, heart attack, it may or may not have been related. Go to the FDA's website, MedWatch and report that. You're just giving the FDA the heads up, hey, there was this association I saw between starting a medication and a serious event, give it a heart attack or stroke. Report those, because the FDA has no other way of tracking safety of supplements. And like we talked about before the FDA is responsible for moving dangerous supplements off the market. So it's really important that we, as physicians, are doing everything we can to get that information to the FDA. When we see it in clinic, hospital, ED.

Unger: We talked a little bit about reform a few minutes ago. The AMA updated and modernized its dietary supplement policy at our meeting last November—which calls for exactly what you're talking about, which is more stringent federal regulation of dietary supplements, including increased oversight of manufacturing, marketing product, labeling, and what you just talked about, which is adverse event reporting. What do you want to see leaders in medicine and public policy, what role do you want to see them playing and achieving this type of reform?

Dr. Cohen: Well, I would love us to be out there in front. I think the AMA's new policy is fantastic and I strongly support it. I think that we need to recognize as physicians that we need supplements to be both very high quality, because we often will need them to treat our patients. Often our patients with iron deficiency, vitamin deficiencies, they're going to need to rely on supplements. It's essential. And we should be assured that when our patients go and purchase their supplements at whatever local store or on the internet, that they're high quality products. So we need to be real advocates for high quality and safety. Because of what's happened in the market, the poor manufacturing, the challenges of manufacturing issues and the challenges with new ingredients being put into supplements—we're dealing with, currently, unsafe marketplace. So the question is how do we ensure that we can both have access to high quality products, but ensure that the access is to safe products too. And that's really going to take a lot of us to get involved. And the AMA's new policy's terrific in advocating for that, and making sure that if there are any proposals or any changes in the laws being proposed, that they are adequate to solve some of these problems we're talking about and not just window dressing.

Unger: Well Dr. Cohen this has been really interesting. Thanks so much for joining us today and sharing your perspective. For more great content on AMA, please subscribe to our Moving Medicine podcast and videocast. We'll be back soon with another segment. In the meantime thanks for joining us and please take care.

Disclaimer: The viewpoints expressed in this video are those of the participants and/or do not necessarily reflect the views and policies of the AMA.