Sea Moss Allergy; Can It Make You Sick?

This may sound a bit strange to those of us who have been consuming Sea Moss for a while now. However, a Sea Moss allergy, or speaking more widely, an allergic reaction to seaweed is a possible thing.

Can it make you sick? Under certain conditions, it is possible that some people can experience reactions that they aren’t ready for.

If you have an experience that you would like to share with your use of Sea Moss, good or otherwise, please let everyone know through the comments at the bottom of this article.

Sea Moss Allergy, Is there such a thing?

So where did the inspiration for this article come from?

One of our Readers left a comment on our article, the Sea Moss Ultimate Guide that read:

I ate too much of it. Which lead to projectile vomiting a later especially explosive diarrhea. I won’t be consuming as much on the future!

However after expelling everything I feel energized and surprisingly well. I like to consume everything I eat raw ( veggies garlic etc).

How do I know how much to eat? Should I weight it?

Because before I ate too much I felt pretty nice. Even now after I puked and spewed everything out I feel GREAT!

I noticed as well that I puked out stuff I didn’t recognize, and I feel like whatever it was it was toxins stored in my gut.

I would prefer to eat it raw rather than make a concoction. Is this wise if I can gauge the right amount?


I would like to say ‘Thank you for the candid comment and your question, Leroy.’ There are a few things to unpack here, so let’s take our time as we walk through the various aspects.

Let me start by saying that this content is not medical advice. Anything published here is for information purposes only and may help when discussing matters with suitably qualified professionals.

Sea Moss Allergy

An allergic reaction to seaweed, including Sea Moss, is a possible thing. But there are certain considerations to make.

Interestingly, the first reported case of a food allergy that was published in connection to seaweed was included in the Journal of Allergy and Clinical Immunology. 1

I think we can agree that food allergies, generally speaking, are on the rise. It’s reasonable to assume that we all know someone who struggles with allergic reactions peanuts, lactose, gluten, shellfish or even avocados. 2

Did you know that if someone has an allergy to avocado they are very likely to also have an allergy to latex?

Specifically looking at seaweed, however, this is a much lesser-known thing to date.

That may be attributed to the number of people who make seaweed a part of their normal diet and the volume consumed. Hence, a larger sample size and more study would be likely to provide interesting data.

Is it an Allergic Reaction or Poisoning?

Let’s not get these confused, food related allergic reactions are different to food-related poisoning. And these are also different to an intolerance to certain types of foods. 3 4 5

For quite a while it was a common belief that unless the seaweed was of a particularly poisonous nature that the chances of a person having some type of reaction were practically negligible.

For example Lyngbya majuscula, which can be found in warmer waters, is one of an estimated 200 species of seaweed that can cause some nasty effects as a result of the toxins found in them. 6 7

It is also worth noting that some species of seaweed can contain other contaminants like high levels of inorganic arsenic. This is the case with Sargassum fusiforme, also known as Hijiki, as highlighted within the Australian Food Standards. 8 9 10

This makes choosing a source of seaweed that is known from a species perspective just as important as it is free from pollutants and harmful chemicals.

Food-related poisoning, allergic reactions, and intolerance will have different consequences depending upon a range of factors, and for some people, the reactions can be serious.

The list of variables related to these is too expansive to go into specific detail here conclusively. But I’ll touch on a few common things to consider that I think could be relevant in this situation.

Considering more than just pollutants

Many people have immediate concerns about toxic substances that may be found in open ocean waters, and the presence of man-made pollutants. However, there can be naturally occurring bacteria and microorganisms that are just as harmful, if not, more harmful.

The presence of marine pathogens in seaweed can include fungi, viruses, bacteria and protozoa. All of which can have serious effects on people.

Testing for disease-producing microorganisms and their toxins is a proactive way that a responsible supplier can take steps to that exposure ensure risks are managed.

Being exposed to these through ingestion will trigger mild to severe reactions, some of which include those described in the question asked above.

Given that simply being exposed to contaminated seawater can present serious concerns, consuming seaweed that has come from contaminated waters can be dangerous too. 11

I have visited places that are Instagram-worthy where Sea Moss is grown for human consumption, only to turn down buying seaweed from them due to infrastructure concerns and water quality challenges.

Domestic runoff is often overlooked by people selling Sea Moss online, yet the impact of human fecal matter in the waters can be catastrophic. Left unchecked, this could make a person very sick.

Purging and Cleansing

When you ingest something that your body doesn’t like, puking and encountering explosive diarrhea, as you put it, are the primary ways the body tries to rid itself of harmful things. 12

Think of these as the body’s emergency exits. The quicker the bad stuff is ejected from the system, the quicker the body can begin working on returning to a balanced state.

A Sea Moss allergy could trigger something like this, but I’m more inclined to think that it’s likely to be some form of contaminant you may have ingested.

The degree of violence that puking as a reaction goes, through can be so intense that the stomach walls can be seriously injured in extreme cases.

The effects of stomach acid on the throat can be uncomfortable, to say the least. Working to avoid this type of bodily reaction is a default setting in my consciousness. 13

If you are looking to purge toxins from your body, there are much less invasive ways from fasting through to ion-water detoxification treatments.

EWWW! That was in my body?

You mentioned that what you saw in your puke you’d identified as what you believed to be stored toxins that had been ejected from your body. That’s completely possible.

Did you know that the colour of the vomit can signify something about what is going on in the body? 14

As anyone who has looked into what something like a parasite cleanse, water fasting, juice fasting, a gallbladder flush and the like could tell you, it’s worrying to think that that stuff was in your body. 15

One thing that I’ve found is that there is increasing evidence that people aren’t drinking enough clean water. As a way to help your body gently detox, keeping your hydration up is a good idea.

I’m not going to dwell on this much more. I’m sure that if you’re truly interested in looking deeper into the topic you’ll find information that is detailed enough.

I would suggest that consuming Sea Moss which you believe triggered the reaction you described, regardless of how good you say felt afterwards, warrants further medical advice. And, I’d probably stop taking it too.

Eating Seaweed Raw

You said that you prefer to eat your food raw, and I get that. I believe that there is enough evidence to support the nutritional and energetic value of raw foods.

We have a few raw recipes online that you might find interesting. My number one is our Raw Red Velvet cake which is completely plant-based and contains Sea Moss.

How do I know how much Seaweed is safe to eat?

I’ve been eating seaweed and adding it to various dishes for quite a long time. One thing I look forward to is being able to enjoy a fresh seaweed salad, made with the Sea Moss we sell, as taken fresh from the ocean.

Sea Moss Salad made with rehydrated seaweed, kang kong, and toeasted peanuts. The sea moss in this salad is golden white and in pieces about 2 inches long. Finely chopped kang kong (a leafy green vegetable) has been tossed through the salad for contrast in color and flavor. This has been topped with toasted peanuts. The seaweed makes up almost 90% of the salad

This seaweed salad, as made by Mr Hai’s wife on my last visit to their open ocean seaweed farm, was fresh and crisp.

The light taste of the Sea Moss which was mixed with finely shredded green papaya, toasted peanuts, kong kang and a little Vietnamese mint was something I enjoyed.

The serving I had during this meal would have been around 8 to 10 ounces of Sea Moss. Afterwards, I didn’t feel anything like what you described, thankfully. I felt like the meal sat light in my stomach and my hunger was satisfied.

Currently, I would estimate that I’m adding about 1/3 of a cup of Sea Moss Gel to various things throughout my day (I tend to go through stages where I use a lot more sometimes compared to other times). And the same thing goes here; I’m not feeling anything untoward.

As far as suggestions on how much you should consume, that’s more a point of conversation I believe you should discuss with your Dietitian.

Once you have an idea of what works for you to meet your nutritional needs, weighing it is the best option. Keep in mind that if you’re getting this in a dried form it will hold a lot of water once it is rehydrated. That water content will subsequently change the nutritional density when you look at the ratios.

I can’t offer you nutritional advice on this as I’m not in a position to, and I would suggest that if there is anything close to a Sea Moss allergy that you may have, speak to a specialist who can see you face to face.

I hope that this has been helpful.


  1. “Seaweed allergy” – I. Thomas, L. Q.C. Siew, T. J. Watts, R. Haque, 21 November 2018 [Journal of Allergy and Clinical Immunology] [Archive] ↩︎
  2. “Dealing with an Avocado Allergy” – E. Carey, G. Whitworth, 8 March 2019 [healthline] [Archive] ↩︎
  3. “Food allergy” – Mayo Clinic Staff, 2 November 2019 [Mayo Clinic] [Archive] ↩︎
  4. “Food Poisoning” – C. Stephens, M. Selner, 7 March 2019 [healthline] [Archive] ↩︎
  5. “Food Intolerance” – ASCIA Staff, 4 May 2019 [ASCIA] [Archive] ↩︎
  6. “Lyngbya majuscula Harvey ex Gomont, 1892” – World Register of Marine Species, 5 September 2012 [WoRMS] [Archive] ↩︎
  7. “Handbook of Marine Microalgae – Chapter 34 – An Overview of Harmful Algal Blooms on Marine Organisms” – P. Manivasagan, S. K. Kim, 8 May 2015 [Science Direct] [Archive] ↩︎
  8. “Arsenic” – CDC, November 2009 [CDC] [Archive] ↩︎
  9. “Sargassum fusiforme (Harvey) Setchell 1931” – M.D. Guiry, 7 May 1999 [AlgaeBase] [Archive] ↩︎
  10. “Imported food risk statement Hijiki seaweed and inorganic arsenic” – FSANZ Staff, June 2016 [Food Standards Australia & New Zealand] [Archive] ↩︎
  11. “Marine pathogens” – M. Lepesteur, G. Rooney, 13 September 2016 [Australian Online Costal Information] [Archive] ↩︎
  12. “Food poisoning: An alphabetical guide to the bugs that cause it and how you can avoid it” – J. Lowinger, 11 July 2016 [ABC] [Archive] ↩︎
  13. “5 Reasons Why Your Throat May Be Burning” – S. Gillson, J. Carew, 12 October 2021 [VeryWell Health] [Archive] ↩︎
  14. “Green, Yellow, Brown, and More: What Does the Color of My Vomit Mean?” – S. Sethi, A. Marcin, 12 March 2018 [healthline] [Archive] ↩︎
  15. “Liver Flukes” – Centers for Disease Control and Prevention, 14 January 2019 [CDC] [Archive] ↩︎

Last Updated on 4 months by D&C Editorial Team

10 thoughts on “Sea Moss Allergy; Can It Make You Sick?”

  1. After taking Sea Moss for nearly a month I began to experience stomach pain, increasing heart rate, dry mouth, dehydration and became very weak. I wasn’t sure what the problem was, while in the bathtub I started saying to myself what is wrong, my diet hadn’t changed, I was wondering why ami I feeling this way, that’s when it hit me the “Sea Moss”, I was taking a teaspoon every other day in my tea, I was so thirsty I had to ask someone to bring me a glass of Alkaline water, I drank the first cup and another and another til I drank 1/2 a gallon of the Alkaline water and instantly felt better. Sea Moss is something my body couldn’t handle.

    • Hi Rene,

      We’re sorry to hear you haven’t had a good experience with Sea Moss.

      My first thought is around the quality of the Sea Moss you are using. Without knowing if your Sea Moss was past its best use date or if it was not stored properly, it is hard to determine the exact reason it would make you feel unwell.

      If you purchased it as a pre-made gel, it could also be anything that the manufacturer has added during the soaking and blending process that could potentially be causing these symptoms.

      However, if your health is being negatively affected by consuming Sea Moss then it simply may be that Sea Moss is not suitable for you. As stated in this article, seaweed allergies do exist but are quite rare. It may just be that you fall into this rare allergy group.

      Hope this helps!

  2. Why when I eat purple sea moss it makes my stomach hurts and I feel nauseated and I only take one tablespoon a day

    • Hello Maiesha,

      That doesn’t sound good to me. If I were you, I would stop taking it and find out more from the Seller about their product and anything that might be in it (various impurities, etc.) and speak with your Doctor.

      It’s well worth getting advice from your Dietitian or trusted Doctor before making changes to your diet, particularly if there is something you are seeking to address.

  3. Hi
    I recently just started using sea moss
    Because i have IBS and am looking for anything that will help ease the discomfort and symptoms,I am however noticing a fine rash on my arms and hands and it’s itchy .Does this mean i am allergic to sea moss? I am not feeling any better from my condition either but maybe it’s still early to notice anything. It’s been a week since I started.

    • Hello Acwengile,

      Thank you for your question. I would suggest you speak with your Dietitian or your trusted Doctor about this. A rash can typically an indication that something isn’t agreeing with you. If I were in your shoes, I would stop taking anything that was recently introduced until I’m sure of what is going on.

      As much as I can’t give you medical advice, I hope this helps you and that you are able to arrange a consultation with someone qualified face to face.

  4. I am a retired RN. My granddaughter sent me Sea Moss gel. What l want to know are there any heavy metals in it that would effect my kidney function.

    • Hello Denise,

      That is a very good question, and one that you know all too well is important. unfortunately, I can’t speak about other places that sell Sea Moss as I don’t know what steps they have taken in quality control and laboratory testing.

      Many people interested in this believe that the seaweed takes up the minerals through the roots that it has, which is incorrect. The minerals are absorbed through the rest of the algae, which means that the waters the seaweed is growing in need consideration too.

      We have searched extensively for the right place to source our Sea Moss. Some of the checks that couldn’t be passed by places we love include domestic and industrial water runoff. For us, this was a shame, as the unseen pollution was a big ‘no’ and it continues to be.

      Seaweed can easily pick up heavy metals and if these are not checked for they can become a problem quite quickly. Some even have a tendency to be high in certain toxic elements, like arsenic in the case of Hijiki. So it is worth asking the specific retailer about their product, and also seeking advice from your Dietitian before making changes as a precaution.

      I hope this helps you.

  5. I took sea moss powder and about 30 minutes after BOTH times I tried it I was projectile vomiting for an hour. First time I didn’t know what caused it. But the second time I realized both times I had just made a shake with the powder. Any idea why?

    • Hello Daniel,

      Thank you for sharing your experiences with us, and adding value to the conversation.

      First, to get the compliance aspects covered, I would like to say that anything shared on our website is not to be considered as medical advice, and if you have a specific concern to see a trusted professional.

      Given the reaction you had, and how you have honed in on what you believe is the cause, if I were in your shoes, I’d stop taking the sea moss powder.

      We don’t sell sea moss powder for a number of reasons. Primarily because of how it is treated to get it to the form that most businesses sell it in. A part of the process can commonly involve irradiation.

      Irradiation might not sound like a big deal as it is commonly used across food manufacturing and water treating to kill bacteria. However, the RSPCA along with other interested parties have called for the banning irradiation of pet food being imported into Australia.

      One strong voice in this space is Phivo, who is known as The Dog Health Guy. He is a good friend of the Detox & Cure Team, and researches everything to within an inch of it’s life. Like us, he’s not prepared to expose his animals, or himself, to these risks.

      The challenge with non-irradiated sea moss powder is that the bacteria and microorganism count can be so high that it is effectively unsafe to consume. That, and there’s no telling what else is in the powder too. It may be packed with all kinds of other things that could trigger various reactions.

      From my experience, choosing to work with the whole leaf raw Sea Moss as a whole food offers you a very different opportunity. Right from the beginning, you can see exactly what it is you’re working with as you prepare your Sea Moss for making a gel from scratch. Anything that looks like it doesn’t belong can be removed, and not indiscriminately ground up into a powder form.

      In summary, without knowing your specific circumstances from a health perspective (to reiterate, this is not medical advice, and I’m not a Doctor) I would guess that you may have either had a reaction to something in the powder as either the Sea Moss itself, or something that night have been a contaminant, or possibly a reaction to how it was processed.

      Something else to consider is what you were mixing it with. Could you have had a reaction to the ingredients in the shake? Or did you have a straight Sea Moss Powder shake?

      Either way, your body knows what is good for it, and an automatic expulsion of something harmful through vomiting is a defense mechanism and helps to reduce your exposure to further harm.

      I hope this has been helpful.

Comments are closed.


About the Author

Matthew has been on an active journey towards living a healthy life from a young age. Influenced by his Grandmother, a practicing Naturopath who served her community from the 1940's to the 1980's, his views on living holistically were shaped from a young age. Growing up in different parts of Australia, his connection with the Ocean and a passion for sustainability comes through in everything he does and shares.

"I'm not a Doctor, and I don't play one on the Internet." - me

Item added to cart.
0 items - $0.00