When Supplements Trend Faster Than the Evidence: Lessons from Sea Moss

When a patient pulls out a trending supplement like sea moss and asks, “Does this actually work?”—what do you say…especially when the evidence is limited?

In this episode, NatMed editors Jeff Langford, Andrea Stafford, and Kelly Daniels use sea moss as a case study to walk through a practical, evidence-based approach to high-hype supplements. 

Questions we answer:

• What is sea moss—and why is it suddenly everywhere?
• What does the evidence actually show (and where does it fall short)?
• How should clinicians respond when patients ask about supplements with weak or uncertain evidence?

We also cover:

• Why dietary supplements are often harder to evaluate than Rx or OTC medications
• Key safety considerations—including iodine exposure and thyroid risks
• How product variability and lack of standardization impact clinical decisions
• A simple framework for counseling patients without over- or under-endorsing trends

🏷️ Our listeners can get 10% off a new or upgraded subscription with code natmed1026 at checkout. 

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NatMed / TRC Healthcare Editor Hosts: 

• Jeff Langford PharmD, BCPS, BCCP (Managing Clinical Editor)
• Andrea Stafford, PharmD (Assistant Editor)
• Kelly Daniels, BA (News Editor & Associate Content Manager)

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CE Information:

This podcast is sourced from the NatMed May 2026 Newsletter. To claim CE credit, subscribers should read the newsletter and click “Take the CE Quiz” link to take the quiz. 

Claim Credit

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The clinical resources mentioned during the podcast are part of a subscription to NatMed: 

• 🌱 NatMed Pro
• 💊 TRC Healthcare
• Newsletter
• Infographic
• Monograph: Sea Moss
• Monograph: Carrageenan

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The content of this podcast is not intended to be a substitute for professional medical advice, diagnosis, or treatment.

Natural Medicines: Evidence in Practice is a production of TRC Healthcare.

Transcript

Introduction

Kelly Daniels 0:03

Picture this. It's a super busy day in your pharmacy or clinic. And as you start your next patient visit, they pull out a container of sea moss powder. Like it's the answer they've finally found. And they ask, My friend swears by this stuff. Does it really help?

Jeff Langford 0:19

And you've got what, a minute or two to respond at best.

Andrea Stafford 0:23

Exactly. And in that moment, you have to juggle several things at once.

Jeff Langford 0:27

Yeah, you're trying to figure out what is this product? What does the patient think it's going to do for them? Are there any red flags I need to consider before responding?

Kelly Daniels 0:35

And how you answer matters, because if the first thing a patient hears is there's no evidence, that could just sound like generic clinicians speak. And patients are likely to tune out from there.

Andrea Stafford 0:46

And that's the tricky part, Kelly, because the truth is almost always more nuanced than that. Weak evidence doesn't mean nothing, it just changes how confident we should be and what we focus the conversation on.

Why Trending Supplements Are Hard in Practice

Kelly Daniels 1:00

So today we're using sea moss as a case study because it's trending in social media. Celebrities swear by it. And when something gets that kind of hype, clinicians start getting questions.

Jeff Langford 1:10

Welcome back to Natural Medicines Evidence in Practice. I'm Jeff Langford, Managing Clinical Editor at Natural Medicines.

Andrea Stafford 1:16

And I'm Andrea Stafford, pharmacist and assistant editor. And I'm Kelly Daniels, news editor and associate content manager.

Jeff Langford 1:23

And if you work with dietary supplements or you're fielding the I saw this online question, this show is going to help you think through a practical approach.

Andrea Stafford 1:32

And we focus on what the evidence does and doesn't tell us and how that plays out in practice.

Kelly Daniels 1:37

Quick reminder before we jump in CE Credit is available through our monthly NatMed newsletter. We'll link everything you need in the show notes.

Jeff Langford 1:46

So back to sea moss. Great example of a trending supplement. The name alone, I think, is enough to capture attention or interest from a lot of people. But before we dive into that, let's zoom out a little bit and answer the question: why is it often so challenging to tackle these clinical questions around trending supplements?

Andrea Stafford 2:07

Yes. And Jeff, it's because they live kind of in a regulatory gray zone. Dietary supplements do not require FDA pre-market approval for safety and efficacy.

Jeff Langford 2:19

And that's really different, Andrea, from the process for prescription and over-the-counter medications, of course. So with prescription meds, FDA has full oversight authority. The company has to prove that safety and efficacy up front before something comes to our pharmacy shelves. But with supplements, oversight is lighter and the products can show up in the marketplace until someone demonstrates they shouldn't be there. So any action and oversight is after the fact instead of prospectively.

Kelly Daniels 2:48

And most patients really don't understand that. So when they're asking about these products, they're not asking, is this proven in a randomized, placebo-controlled trial? They're asking, is it safe? Am I missing out on something that can really provide some benefit? So just a flat there's no evidence can really feel like a brush off, especially if they've already been taking it or they know someone who swears by it.

Jeff Langford 3:11

Right, Kelly. And often it's a difference, or it may be due to how patients first became interested in a particular supplement. They may not be starting with the problem and working algorithmically through all of the different treatment options to find the best one for them. They may just be interested in this because of a friend's recommendation, a really cool ad or a viral social media post that got their attention. And sea moss is really a good example of what can happen when nutrient content, traditional use, and the social media momentum kind of collide, and then clinicians are left to sort it all out on the front line.

Andrea Stafford 3:47

Yes. And

What Is Sea Moss (Irish Moss)?

Andrea Stafford 3:48

kind of before we get into evidence for sea moss, it helps to kind of clear up on what sea moss actually is. So sea moss usually refers to Chondrus crispus, a type of red seaweed commonly found in the northern Atlantic, also called Irish moss. And not to get too far into the weeds on this, if you kind of picked up what I did there with words, sea moss shouldn't be confused with other types of seaweed like dulce.

Jeff Langford 4:18

Yes, Andrea, we see you there. Trust me. Sea moss is mostly water, but it's a natural source of macronutrients like carbs, protein, fat, and small amounts of vitamins and minerals. Iodine is notably one of those uh micronutrients that's found there. And historically, sea moss has been used as a food or medicine, like medicinal teas for cough, for example. And it's also a source of carrageenan, the food additive that helps to thicken and emulsify foods.

Andrea Stafford 4:48

But the modern claims around sea moss, like energy, immune support, or gut and skin health, are much newer than those traditional uses that you just mentioned, Jeff, such as cough.

Kelly Daniels 5:00

Right. And those claims really are everywhere. I hear that people are blending it into their morning smoothies as a daily wellness habit. Others are taking it as a supplement in capsule form. So that gap between its traditional uses and how it's being really pushed and marketed now is very different. And that can lead to a lot of questions.

Jeff Langford 5:17

So,

What the Evidence Actually Shows

Jeff Langford 5:18

Andrea, what does the evidence actually show for sea moss and where does it fall short? I think this space may be where clinicians sometimes feel uncomfortable because patients assume there must be studies.

Andrea Stafford 5:29

Yes. And Jeff, honestly, for sea moss, the evidence is limited, at least when it comes to the kind of high-quality human data we want to lean on clinically. We do have some lab and animal studies with sea moss, but most of our clinical data hinges on one small observational study in a heterogeneous population looking at chronic pain, fatigue, and quality of life. Now, patients did report improvements in these areas, but the study lacks an appropriate comparator group and has several other limitations that we can take into consideration.

Jeff Langford 6:03

Okay, Andrea, I'd like to just kind of pause here for a minute and think about the kind of data you just described, because that type of study is really similar to what we run across in a lot of different natural medicine studies where the data may be particularly limited. And those kinds of limitations really are important to think about when we're trying to decide what to do or what to recommend. So just to drill down on two things that you mentioned, you talked about a very heterogeneous population in this study. And that really can make it quite hard to pluck out what is the real effect of an intervention. It can make it difficult to drill down onto the patients that did or did not benefit. So we'd like ideally in a well-designed study to have different groups represented, but then be super balanced between those comparison arms. Also not having that placebo group, as you mentioned, that leaves us really uncertain what drove the difference. Was it the intervention itself, like the sea moss? Or is it due to people just expecting a benefit, perhaps natural fluctuation in their disease state, or something else? So it leaves us with a lot of questions.

Kelly Daniels 7:12

Okay, but if I'm a patient and I hear you'll feel less tired if you take sea moss, for example, that still sounds pretty compelling, even if evidence is pretty murky, as you say, Jeff.

Andrea Stafford 7:24

It does. And that's the challenge. Feeling better is important to patients, and it's not something to be ignored. But in cases like this, we're often not certain if it's the supplement that helped. Plus, it's also important to remember or know, for example, if it improves other outcomes like pain med use.

Jeff Langford 7:45

Yeah, those are really fair points. And I think we can figure out perhaps a better way to phrase what we know about something so that patients here can better understand why they think it might be helpful for them while also really sticking to an evidence-based approach. And so we could, for example, it might be better to spin this as we don't have strong, reliable human trials for those claims yet. That means we can't count on a benefit, but we can help them understand what the evidence suggests. We just want to frame that correctly without over-promising or overstating the outcomes.

Andrea Stafford 8:19

Exactly, because this observational study hints at a signal, but this isn't data that we would necessarily want to hang our hat on.

Safety: Iodine and Thyroid Risk

Jeff Langford 8:28

And we always want to balance those conversations about benefit with safety, answering the question, you know, what could go wrong? And of course, the benefit efficacy is only one side of the coin. A lot of times these studies provide very little data on safety outcomes.

Andrea Stafford 8:44

And from a safety standpoint, like Jeff brought up, sea moss is likely safe for most people when used in common food amounts. So if someone's blending a little in their morning smoothie, that doesn't sound like a big deal, right? Right. And for many people, it probably isn't.

Jeff Langford 9:01

But where we need to pause and really evaluate is when that very small food-level type use turns into a supplement-level use.

Andrea Stafford 9:11

Yes. And with sea moss, one key concern is iodine. It naturally contains iodine, roughly four to seven micrograms per gram. And that matters because iodine intake directly affects thyroid function. And total daily intake of iodine needs to be below the tolerable upper intake level of 1,100 micrograms.

Kelly Daniels 9:35

But if someone's just casually taking sea moss every day, is that really enough iodine to cause a problem?

Andrea Stafford 9:41

On its own, in a healthy patient staying underneath that tolerable upper intake level, probably not. But patients aren't usually tracking iodine across supplements. And for people with thyroid dysfunction or those taking thyroid medications like levothyroxine, extra iodine can become a problem.

Jeff Langford 10:01

And of course, Andrea, that's the basis for drug interactions that we have in our NatMed database for sea moss. We flag potential interactions with antithyroid meds, with thyroid hormone replacements, as well as substances that contain iodine, like the drug amiodarone. And it goes back to really what you mentioned. We know that iodine is required to produce the thyroid hormone, but excess iodine really is unpredictable in its effects, and it depends on patient-specific factors. So, for example, if a patient has underlying thyroid disease, excess iodine, depending on their underlying disease state, can either cause the hyperthyroidism or low thyroid levels or hypothyroidism. So it can go in either direction depending on what kind of problem, underlying condition they have.

Kelly Daniels 10:53

So the clinical concern here isn't exactly sea moss itself and that it's dangerous on its own. It's really the potential cumulative exposure if someone's taking multiple products like multivitamins that also contain iodine in addition to the sea moss every day.

Andrea Stafford 11:08

Yes. And

Product Variability and Contamination Risks

Andrea Stafford 11:10

that risk, Heli, is compounded by the fact that sea moss lacks product standardization. Its iodine and nutrient content can vary based on sourcing, processing, and storage.

Jeff Langford 11:22

Plus, depending on where sea moss is grown, there can be some concerns for things like heavy metal accumulation, substances like lead, arsenic, or mercury, again, with variability depending on where that sea moss is grown or sourced.

Kelly Daniels 11:35

Which means two products, both labeled sea moss, might not really be comparable. Right.

Andrea Stafford 11:40

And when benefit is uncertain, that kind of variability and unknown exposure is often enough to recommend caution, particularly in patients of higher risk.

Jeff Langford 11:51

Okay, Andrew.

Sea Moss Bottom Line

Jeff Langford 11:52

So we asked at the top of this conversation, like, tell us about the evidence for sea moss. And I think that I heard is that there's a lot of claims for sea moss across a wide range of areas, but we really don't have solid clinical evidence yet supporting any of those specific uses. We think it's generally safe and food amounts, uh, but we do need to be alert for patients with thyroid conditions because the effects in those patients might be variable due to the iodine content.

Andrea Stafford 12:21

Yes, exactly.

Andrea Stafford 12:22

Patient Case and Framework for Conversations

Jeff Langford 12:23

So I think we want to turn a little bit and think about how do we navigate the balance of these conversations, validating the patient's interest without over-endorsing. And I think that's where we really we can benefit from a framework for these conversations in practice.

Kelly Daniels 12:40

Okay, so let's make it real. Imagine a patient comes up to the counter and says, I've been adding sea moss powder to my smoothies. I keep hearing it's great for energy, immune function. I'm tired all the time and I already take a multivitamin. Is this going to help? Should I keep taking it?

Andrea Stafford 12:56

And those are all great kind of questions that a patient could bring to the clinic or the pharmacy. And the first thing I'm thinking about isn't necessarily what to recommend. It's what do I need to know first. And I start with kind of three targeted questions. Are you using food amounts or are you taking it as a concentrated supplement? And this is where if the patient has the product in hand, I would actually take a look at it and kind of verify the amount and what other ingredients are in it. I'd also want to know with pertaining to sea moss, do you have a thyroid condition or are you on any thyroid-related medications? And I'd also want to clarify what other supplements or natural products are they using? Because oftentimes when you ask a patient, what else are you taking, they aren't considering maybe other medications over the counter or supplements.

Jeff Langford 13:44

Yeah, Andrea, I think those are good. And some other things that come to my mind that are important things to kind of tease out and practice or figuring out what else a patient has tried for a given condition. Yes. Like in this case, we said we don't have a ton of evidence, but if they tried 15 things that didn't work, we might be moving further down on that list of things that become realistic options. Also thinking about and identifying the answer to why they're interested in this specific option. Maybe it came up, as we mentioned earlier, just because of a social media post, and we can help give a broader view of information about this product as well as other things. And also thinking through what are the patient's specific goals for their treatment, again, understanding where they want to go can help us tailor recommendations in in conjunction with the patient.

Kelly Daniels 14:34

Right. Yes. And depending on the answers to those questions, you might have an entirely different conversation.

Andrea Stafford 14:40

Exactly. And if the patient is using a small amount in food form and has no thyroid history, then my guidance would be while the benefit is uncertain, this amount is likely safe and think of it as optional, not necessary. But Jeff, what if they're taking sea moss as a supplement, stacking products, or have a thyroid disease? Where could where would this conversation go?

Jeff Langford 15:04

Yeah, I think that kind of spins things in a different direction. And that's really where I would start to pump the brakes and think twice about what we're going to suggest a patient would do. We'd already said evidence for benefit is sparse. We do have this potential risk. So if we've got, for example, a patient with hypothyroidism taking like levothyroxine as thyroid replacement. The management of that alone requires pretty close oversight and some fine-tuning often to get the dose just right for some patients. So in that case, to me, that would be enough of a reason to lean away from sea moss in that particular circumstance, especially for someone that had had frequent dose adjustments or difficulty identifying the right dose of their thyroid hormone replacement. I wouldn't want to introduce anything to make that more complicated.

Kelly Daniels 15:53

So the goal isn't always just a flat yes or no. It's really to help the patient understand where the unknowns are and help guide them in the right direction.

Jeff Langford 16:01

Right. We're working toward really that shared decision making. It doesn't mean and certainly does not mean endorsing a product we don't prefer to use. At the same time, we don't want to dismiss the patient or the things that they may be interested in or have a preference for.

Andrea Stafford 16:16

Yes. And sea moss might be trending now, but this framework that we talked through, kind of asking key questions to better understand the patient's goals, their relevant medication history, and sharing that risk-benefit consideration to arrive at a shared decision can apply to whatever supplement is trending.

NatMed Tools and Resources

Jeff Langford 16:40

And if you're thinking, I get the framework, but I don't want to rely on memory for every detail of these supplements. That is exactly where NatMed fits into practice.

Andrea Stafford 16:50

Yes. And in a situation like this, you can pull up the sea moss monograph or the newsletter article right at the point of care to confirm what the evidence says, what the safety considerations are, and answer maybe questions that aren't clear.

Kelly Daniels 17:05

Right. And that makes it a lot easier to show patients here's what we actually know and here's where the uncertainty is, instead of just feeling like you're giving your personal opinion about something.

Jeff Langford 17:15

Exactly, Kelly. It really supports that conversation and not just the conclusion.

Andrea Stafford 17:20

Plus, NatMed includes CE options and our monthly newsletter for ongoing updates and practical clinical pearls.

Kelly Daniels 17:28

And listeners can save 10% with code NatMed1026 at checkout. Links are in the show notes.

Final Takeaways

Andrea Stafford 17:40

So the bottom line, the evidence for sea moss is limited, but the framework we walked through today that can be applied every time a patient brings in the next trending supplement.

Jeff Langford 17:52

Yeah, when the benefit is uncertain, the goal is really to ask the right questions, to recognize who is at higher risk and help to evaluate that benefit versus risk in a very patient-specific manner.

Kelly Daniels 18:04

And from the patient side, this can feel like a collaborative partnership where they feel like their needs are heard and they can get objective evidence to inform their decisions.

A Few More Things…

Andrea Stafford 18:15

To claim CE, follow the instructions linked in our show notes. We've also included links to the sea moss newsletter article, the monograph, and other tools we discussed so you can bring these tips straight to practice.

Kelly Daniels 18:27

And if you want to keep going, the main newsletter covers several other timely topics, including helping parents navigate supplement safety in kids and teens, breaking down black kohosh and soy for menopause, and in our most recently published June newsletter, we dive into creatine for mental health as well as weight loss alternatives.

Jeff Langford 18:48

And if you know a colleague who keeps getting asked about trendy supplements, we'll share this episode in our show with them.

Andrea Stafford 18:55

Thanks for listening to Natural Medicines, evidence in practice. Evidence, not hype.

Jeff Langford 19:00

See you next month.