Are Kelp and Seaweed The Secret to Clear Skin?


There’s a lot of confusion out there around whether or not iodine, and foods high in iodine, like seaweed and kelp, help prevent acne or cause it.  Some people claim that eating seaweed or taking a kelp supplement helped improve their overall health and their skin, while others, especially old-school dermatologists, believe that iodine actually causes acne.

Who should you believe?

Well, after digging into the latest research, the answer is clear: having enough iodine is crucial for fighting off acne and improving your health, but consuming too much iodine can cause more problems than just acne – it can lead to serious health issues like hyperthyroidism.

Basically, just like other skin-clearing nutrients, including zinc and vitamin A, you can have too much of a good thing.  Too much iodine is just going to cause more acne.

But how do you know if you need more iodine?  Why is iodine crucial for clear skin in the first place?  Is it possible to get iodine naturally through your diet?

Stay patient – we’re going to answer all those questions and more in this article.

Why Iodine, Kelp, and Seaweed Are Great For Acne

Let’s clear something up really quick – the main reason that we’re talking about kelp (which is just a certain type commonly eaten seaweed, by the way) and acne is that it’s an amazing source of iodine.

Sure, there are plenty of side benefits to eating kelp that may help improve symptoms of acne:

  • Kelp may reduce oxidative stress and inflammation – inflammatory acne is a real pain to deal with and one of the root causes of pimples1https://www.ncbi.nlm.nih.gov/pubmed/23006515
  • Kelp can help lower levels of insulin – insulin is an acne-causing hormone typically triggered after meals containing large amounts of carbohydrates.  It’s why you tend to break out after a sugary or carb-filled meal2https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815322/
  • Kelp may at as an antioxidant and help protect the skin from air pollution, UV damage, and free radicals3https://www.ncbi.nlm.nih.gov/pubmed/24897795
  • Kelp also contains a decent amount of vitamin K, an essential fat-soluble vitamin

But at the end of the day, the main benefit of kelp for your health and your skin is that it’s a natural source of iodine. If you do not have access to fresh kelp or hate the taste I suggest trying a sea moss supplement. Sea moss is anti-inflammatory and a great source of iodine. Additionally, sea moss is ultra-hydrating for the skin and does not contain any comedogenic ingredients.

So, why the heck is iodine so important for beating acne? Basically, because your thyroid needs iodine to function properly – and an unhealthy thyroid means unhealthy skin.

Why Hypothyroidism Might Be Behind Your Acne

If you’ve seen our Ultimate Guide to Thyroid-Related Acne, you know just how important a properly functioning thyroid is for your mood, energy, and skin.

There are two main types of thyroid disorders:

  • Hypothyroidism – An underactive thyroid – the thyroid doesn’t produce enough thyroid hormone
  • Hyperthyroidism – An overactive thyroid – the thyroid produces too much thyroid hormone

While both hyper and hypothyroidism are can lead to skin problems, hypothyroidism (an underactive thyroid) is really what we want to watch out for when it comes to acne.

  • Hypothyroidism leads to an imbalance of female sex hormones that can cause cystic and stubborn hormonal acne
  • 90% of people with an underactive thyroid have a specific type of hypothyroidism called Hashimoto’s Disease, which is caused by an overactive immune system.4https://www.ncbi.nlm.nih.gov/pubmed/3066320 A faulty immune system is a key component in inflammatory acne
  • Both hyper and hypothyroidism lead to dry, flakey skin that can clog and block pores.  This makes them more prone to acne bacteria and infections

Despite being widely ignored by dermatologists, thyroid health is one of the most important components in skin health.

It begs the question – what causes hypothyroidism?  It’s almost always a combination of things, but some of the most common include a diet high in refined carbohydrates, undereating, excess fluoride consumption, and iodine deficiency.

Iodine helps the thyroid regulate the number of hormones it releases – if the thyroid doesn’t have enough iodine, it can’t make sure that your body is getting all the thyroid hormone it needs to function properly.  This leads to hypothyroidism and acne.  On the flip side, too much iodine can overstimulate the thyroid and lead to hyperthyroidism along with more dry, flakey, acne-prone skin.

Yikes, you just can’t win, can you?

Let’s go over how you can tell whether or not you should consider taking an iodine or kelp supplement to help with acne.

Should You Take Kelp/Iodine for Acne?

Believe it or not, not too long ago, our ancestors used to get tons of iodine through our seafood-rich diets.  Now I’m not one to claim that the Paleo diet is perfect or that we all need to eat like a caveman, but there is something to say about our decreasing consumption of kelp, seaweed, fish, shrimp, and shellfish.

Iodine consumption has decreased by 50% since the 1970s.5https://journals.aace.com/doi/pdf/10.4158/EP14472.CO  Rates of hypothyroidism are at all-time-highs, affecting upwards of 10% of the population.6https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3970282/  For people with acne, the odds of having some sort of thyroid disorder are significantly higher.7https://www.ncbi.nlm.nih.gov/pubmed/21521376

Generally-speaking, we’re not eating enough real foods that are rich in iodine to support our thyroid. Sure, some companies have added iodine table salt, but it usually just creates more problems than its worth – many table salts contain moisture absorbents, anti-caking agents, flow agents, and other heavy metals that can cause a wide array of health issues.

That’s why many people, especially those with hypothyroidism, may want to consider supplementing with iodine. While a blood test is the easiest way to determine whether or not you have thyroid problems, for those who can’t afford a doctor’s visit there is a ton of at-home tests and symptoms to check for. Generally speaking, a cold resting body temperature, a low resting heart rate, and symptoms including acne, dry flakey skin, constantly feeling cold, hair thinning or hair loss, lack of energy, and muscle weakness.

In our Guide to Thyroid-Related Acne, we go over more of the details on how to tell if you have hypothyroidism.

As a whole, unless you’re eating a large amount of seaweed on a regular basis, or very large amounts of cod, tuna, shrimp, or eggs, there is a pretty decent chance that you could use some more iodine in your diet.

But what’s the best way to add iodine to your diet? Do iodine supplements really work?

Best Iodine and Kelp Supplements for Acne

First things first – I am a huge advocate for getting your nutrients through whole foods whenever possible.  With that being said, there are a lot of nutrients that are necessary for clear skin, like zinc and vitamin D that can be difficult to get through food alone.

Iodine is another one of those nutrients – there are good food-based sources, but for those of us who don’t have access to wild-caught seafood, it can be tricky to get enough iodine in our diet:

  • Seaweed/Kelp has upwards of 66 mcg of iodine per gram (44% daily value) – a gram is an extremely tiny amount of seaweed, by the way 8https://www.ncbi.nlm.nih.gov/pubmed/15588380
  • Cod has 63mcg of iodine per 3-ounce serving (42% daily value)
  • Tuna has 17 mcg of iodine per 3-ounce serving (11% daily value)
  • Shrimp has 35 mcg of iodine per 3-ounce serving (23% daily value).  By the way, make sure you get wild-caught shrimp.  Most farmed seafood, including shrimp, is a nightmare for acne.

Dairy is also high in iodine, but posses a ton of problems for acne-prone skin, from spiking hormones to damaging the digestive system.  Same goes for some legumes high in iodine – they contain antinutrients and compounds that just make acne worse.

Because iodine is so tricky to get through food alone, a lot of people may want to consider taking a natural kelp supplement to help with this – I did this when I was struggling with hypothyroidism and saw considerable improvements in my symptoms, including acne, after about a month of supplementation.

I recommend Bulletproof’s Iodine Supplement for a few reasons:

  • It contains the perfect amount of iodine at 150mcg per serving (100% daily value).  Many kelp supplements contain too much iodine, which can lead to hyperthyroidism if you use it for too long
  • The main ingredient is real, whole kelp from Iceland – this means the iodine will be bioavailable and safe to consume
  • 100% non-GMO and gluten-free

If you have thyroid-related acne, and you aren’t getting enough iodine through your diet alone, you may want to seriously consider taking a kelp supplement to help get your thyroid back in check.  After my hypothyroidism symptoms got better, I still supplemented with kelp, just on a less frequent basis – remember, too much iodine can just lead to an overactive thyroid, which can cause just as many problems like an underactive thyroid.

Before you consider buying an iodine supplement, we have one more really important area to cover when it comes to kelp, seaweed, and iodine for acne – and that’s fluoride.  If you want your iodine supplements to be effective at treating thyroid disorders, you need to decrease your fluoride consumption – here’s why.

Fluoride, Iodine, and Acne

You know a little bit about fluoride, right?

It’s a mineral found in toothpaste, tea, produce, and (unfortunately) tap water.

What you probably don’t know is that excess fluoride consumption can be a nightmare for your thyroid and acne.

Believe it or not, the fact that fluoride triggers inflammation (which leads to acne and pimples) and depletes the body of certain acne-fighting nutrients and antioxidants is the least of your worries.9https://www.ncbi.nlm.nih.gov/pubmed/20399260  The worst part about fluoride is that it competes with iodine to fill certain receptors in the body specifically designed for halogens (iodine, fluoride chlorine, bromine).

When you consume fluoride, you’re basically filling up receptors where your body could store iodine.  This makes it harder to absorb iodine through our diet and supplements and increases our risk for iodine deficiency.

What does iodine deficiency lead to?  Hypothyroidism.  What does hypothyroidism lead to?  Acne.

Long story short, if you’re consuming too much fluoride, iodine supplements might not even be much help – you need to cut back on fluoride and increase iodine consumption to straighten out your thyroid.

I’ll be writing a full article on how to limit fluoride exposure soon, but for now, here are a few tips:

Closing thoughts

Okay, okay, I’m done lecturing.  Hopefully, by now you understand why kelp, an iodine powerhouse, may be effective at treating thyroid-driven acne.

Still, if you’re someone who is dealing with non-thyroid acne, like hormonal acne, inflammatory acne, or acne caused by another autoimmune condition, you’ll want to proceed with caution when it comes to kelp and iodine supplements, as they may lead to more problems than their worth.

Have you tried taking an iodine or kelp supplement for clear skin?  Do you have a question about the link between diet, acne, and your thyroid? Drop it in the comments below!

Originally Published: April 22, 2019

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sam wood is GoodGlow's Chief Editor
Analyzed by Sam Wood

Hi, I’m Sam Wood, the chief editor, lead acne expert, and health coach at GoodGlow, as well as a best-selling author for one of the top acne books on Amazon. I struggled with acne for over 10 years, and began studying the effects of diet on skin quality while pursuing a degree in Nutrition Sciences at the University of Missouri. After shifting from mainstream skincare trends to in-depth research in medical journals, I experienced significant personal success in managing my acne. This inspired me to start GoodGlow, where I simplify complex scientific findings into easy-to-understand advice. With over 10 years in the field, I’ve helped more than 2,500 people achieve clearer skin through natural, holistic methods, and I’m dedicated to personally assisting those seeking guidance on their acne journey.

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