Your Go-To Guide To The Best Iodine Supplements For Thyroid Support

Iodine Supplements

As a functional medicine expert, I understand the important role iodine plays in maintaining optimal health - especially when it comes to your thyroid. However, it is one of the most common nutrient deficiencies, affecting 35-45% (1) of the world’s population. But seeing as iodine intake is severely lacking in most people’s diets, supplementation is often necessary to correct deficiencies and support thyroid function.

Instead of leaving you to search Dr. Google hours on end, I’ve put together a list of the best iodine supplements on the market. From capsules to liquid drops, read on to learn more about iodine and find which of the best iodine supplements is right for you.


Make Your Life a Cleanse



Get FREE access to these + giveaways, recipes, & discount codes in personal emails from Dr. Will Cole.

What is iodine?

Iodine is a trace mineral that’s found naturally on earth and in certain foods. It is considered an essential nutrient because your body doesn’t produce it on its own which means that you have to get it through food or supplementation. 

But the problem with iodine is that it is not found in many common foods. For example, the foods highest in iodine are sea vegetables like dulse and seaweed. And since most people don’t eat enough iodine-rich foods, deficiencies are common that can have a variety of health consequences - specifically when it comes to your thyroid health.

The connection between iodine and your thyroid hormones

​​Iodine isn’t just important to the thyroid — it’s a part of thyroid hormones themselves. You may have heard of “T3” and “T4” thyroid hormones; well, “3” and “4” stand for the number of iodine atoms it takes to produce each of these hormones. When you don’t get enough iodine, it can influence your thyroid hormone synthesis, which is a problem because the thyroid is largely in control of your metabolic activity. Iodine deficiency is often an underlying cause of thyroid issues and is something I always look at in my patients with existing or suspected thyroid problems.

The best iodine supplements

With countless iodine supplements on the market, it can be overwhelming to sift through what’s out there. That’s why I want to help cut the confusion and give you my top recommendations for the best iodine supplements.

1. MaryRuth Organics Liquid Iodine supplement

MaryRuth Organics is a brand that I trust completely as all of their products are vegan, gluten-free, non-GMO, GMP facility made, and B Corp certified. One of the best liquid forms of iodine on the market, these drops make it extremely easy to get in your daily iodine, especially if you aren’t a fan of taking capsules.

Price: $21.95

Dosage: 250 mcg / 167% DV

2. NOW Supplements Kelp

Derived from pure organic kelp, NOW kelp capsules are a great affordable option if you are not ready or don’t have a lot of money to invest in an iodine supplement. NOW prides itself on its extensive ingredient testing and all of their manufacturing facilities are FDA-approved so you don’t have to sacrifice quality in exchange for budget.

Price: $12.99

Dosage: 150 mcg / 100% DV

3. Pure Encapsulations Iodine

Another budget friendly option that can be purchased on Amazon for quick shipping, Pure Encapsulations Iodine is free from GMOs, allergens like wheat, dairy, soy, eggs, and tree nuts, artificial colors, preservatives, and sweeteners, and unnecessary coatings, binders, and fillers. Plus, all of their supplements are third-party tested and manufactured locally in Massachusetts.

Price: $18.90

Dosage: 225 mcg / 150% DV

4. Thorne Iodine & Tyrosine

If you are struggling with your thyroid health, this iodine supplement from Thorne is a game-changer because it also contains tyrosine - an amino acid that plays a role in thyroid hormone production. Coming in at $20, this supplement is an affordable option that is free from common allergens and is tested for both purity and potency. The serving size is also just one capsule which is nice if you take multiple different supplements.

Price: $20

Dosage: 225 mcg / 150% DV

5. Life Extension Sea Iodine

Unlike most other iodine supplements, Life Extension’s Sea Iodine provides a higher dose of iodine in each serving from kelp and potassium iodine. All Life Extension supplements come with a Certificate of Analysis for complete transparency so you never have to second guess what’s inside the supplement you are taking. Just remember, this amount of iodine isn’t for everyone so talk with your doctor before taking this type of high-dose iodine to make sure it is right for your health case.

Price: $6.00

Dosage: 1,000 mcg / 667% DV

What to know before taking iodine supplements with thyroid problems

It’s important to note that correcting an iodine deficiency is not as simple as getting more iodine, especially if you struggle with thyroid problems. As we mentioned earlier, iodine is an essential component of thyroid hormones, and maintaining an appropriate balance of iodine intake is crucial for thyroid health. However, the relationship between iodine supplementation and thyroid disorders such as Hashimoto's disease, hyperthyroidism, and hypothyroidism is far from straightforward. 

On one hand, for individuals with Hashimoto's disease, there is concern that excess iodine intake can perpetuate inflammation and thyroid dysfunction. For example, one recent study published in 2022 indicated (2) that excessive iodine intake may trigger or worsen hypothyroidism and thyroid autoimmunity in susceptible individuals. That same study also noted that a transient hyperthyroid condition can also increase your body’s uptake of iodine that can further exacerbate your thyroid problems.

But with that said, another study published in the journal Immunologic Research (3) also noted that we can’t necessarily conclude that iodine intake is the sole perpetuator of thyroid autoimmunity, as the mechanisms behind iodine consumption and its relationship to each person’s individual thyroid biochemistry are still being observed. It also doesn’t take into account the many other factors that play a role in developing thyroid problems including genetics, diet, and environmental toxins that can vary drastically between individuals. 

Ultimately, it all comes down to your individual biochemistry. After all, we can’t argue the fact that studies have concluded (4) that iodine deficiency does also contribute to thyroid problems just as much as excess iodine does. Therefore, when it comes to iodine and iodine supplements, we must follow the goldilocks principle. It’s important to work with a functional medicine expert who can take a whole-body approach to your health. By looking at your current iodine levels in relationship to your genetics, thyroid labs, diet, toxin exposure, and whether or not you are experiencing a flare, they can determine the best course of action moving forward - including whether or not iodine supplements are best for your case and at what dose - while monitoring your progress.

Do you have low iodine?

Since low iodine levels can lead to various health issues, it's important to be aware of the signs and symptoms of iodine deficiency. Here are some common symptoms that often coincide with low iodine and thyroid problems:

  • Fatigue 
  • Weight Gain / weight loss resistance
  • Sensitivity to cold
  • Dry Skin
  • Brittle nails
  • Hair loss
  • Brain fog
  • Swelling
  • Mood swings
  • Depression
  • Anxiety

One of the biggest signs of iodine deficiency is the presence of a goiter. This happens when your thyroid gland becomes enlarged and is characterized by swelling or lump in the front of your neck, just below your Adam’s apple. Although not everyone with a goiter has low iodine levels, it is an important indicator that something is off.

If you are experiencing any of these symptoms and suspect that iodine deficiency is the cause, your doctor can recommend lab work to determine your current iodine levels. I also recommend running a full thyroid panel to assess your thyroid function to determine if you have any underlying thyroid problems as a result of prolonged iodine deficiency.

In functional medicine, we run a more in-depth range of tests and look at a narrower range of optimal results. 

Read my article here to learn more about thyroid labs.

Choosing the right iodine supplement for you

Choosing from the best iodine supplements goes far beyond buying whatever is available at your local grocery store. Here are some steps to consider when selecting an iodine supplement:

1. Consider your baseline and dosage

The first step before purchasing an iodine supplement is to determine your level of deficiency through lab work. Once that has been established, your doctor will be able to recommend the appropriate dosage depending on your individual health case.

2. Determine supplement delivery method

Iodine supplements are available in various forms from capsules to liquid tinctures. Choose a form that is convenient for you to take and suits your personal preferences.

3. Vet quality and purity

It’s essential to ensure that the iodine supplement you choose is of high quality and purity. Look for supplements from reputable brands that are transparent about their ingredients, sourcing, and manufacturing practices, and have been independently tested for purity and potency. Some brands even provide clinical studies to support the effectiveness of their individual products. 

4. Check for allergens and additives

If you have allergies or sensitivities to certain ingredients, check the supplement's label for potential allergens, fillers, or additives that could negate some of the positive benefits of taking iodine in the first place.

5. Take your diet into account

If you are increasing your intake of iodine-rich foods be sure to take that into account when factoring supplementation so that you don’t go overboard and turn iodine deficiency into iodine excess.

READ NEXT: The Superfood Benefits of Sea Moss + Risks Debunked

Additional thyroid support tips

There are going to be many different tools you can use to support your thyroid depending on your individual health case and underlying cause of your thyroid problems. However, these are some of my top ways to facilitate healthy thyroid hormones.

1. Manage stress levels

Chronic stress has been linked (5) to the onset of thyroid problems due to the fact that cortisol can affect the conversion of thyroid hormones.

2. Heal your gut

Approximately 20 percent of your T4 is converted to T3 in the gut, and an imbalanced, unhealthy microbiome can inhibit this process. Some of my favorite tools to facilitate a healthy gut include bone broth and a daily probiotic supplement, but you can check out my complete guide to healing your gut here.

3. Limit toxin exposure

Between the food we eat and the products we use, we are exposed to an onslaught of toxins on a daily basis. Everything from heavy metals to pesticides to xenoestrogens can lead to an autoimmune response (6) against your thyroid.

4. Up your selenium intake

Selenium is essential for your body to convert T4 to T3. Without this conversion, your body will overproduce the unusable form of your thyroid hormone that can end up blocking thyroid function. I recommend eating 2-4 Brazil nuts a day as they contain enough selenium to meet your daily requirements without supplementation.

While this is not a complete list of how to support your thyroid, these tips can act as a starting point and are foundational for both thyroid and overall health. You can learn more about ways to support your thyroid health along with other triggers for thyroid problems, here.

Find the root cause of your thyroid issues

Identifying the root cause behind your thyroid issues is the first step in overcoming your symptoms. A functional medicine practitioner will be able to work with you in uncovering the driving force behind your symptoms - whether that is iodine deficiency, something else entirely, or a combination of factors - and come up with a plan of action. 

From finding the best iodine supplements for your health case, labwork, or offering additional dietary and lifestyle recommendations, my team and I specialize in offering personalized functional medicine care no matter where you are in the world.

If you are struggling with an iodine deficiency or underlying thyroid problem, schedule a telehealth consultation today to learn more about how we can help you with functional medicine.

As one of the first functional medicine telehealth clinics in the world, we provide webcam health consultations for people around the globe.


Start Your Health Journey Today


  1. Hatch-McChesney, Adrienne, and Harris R Lieberman. “Iodine and Iodine Deficiency: A Comprehensive Review of a Re-Emerging Issue.” Nutrients vol. 14,17 3474. 24 Aug. 2022, doi:10.3390/nu14173474
  2. Kalarani, Iyshwarya Bhaskar, and Ramakrishnan Veerabathiran. “Impact of iodine intake on the pathogenesis of autoimmune thyroid disease in children and adults.” Annals of pediatric endocrinology & metabolism vol. 27,4 (2022): 256-264. doi:10.6065/apem.2244186.093
  3. Teti, Claudia et al. “Iodoprophylaxis and thyroid autoimmunity: an update.” Immunologic research vol. 69,2 (2021): 129-138. doi:10.1007/s12026-021-09192-6
  4. Zimmermann, Michael B, and Kristien Boelaert. “Iodine deficiency and thyroid disorders.” The lancet. Diabetes & endocrinology vol. 3,4 (2015): 286-95. doi:10.1016/S2213-8587(14)70225-6
  5. Matos-Santos, A., Nobre, E.L., Costa, J.G.E., Nogueira, P.J., Macedo, A., Galvão-Teles, A. and De Castro, J.J. (2001), Relationship between the number and impact of stressful life events and the onset of Graves' disease and toxic nodular goitre★. Clinical Endocrinology, 55: 15-19.
  6. Langer, Pavel et al. “Fish from industrially polluted freshwater as the main source of organochlorinated pollutants and increased frequency of thyroid disorders and dysglycemia.” Chemosphere vol. 67,9 (2007): S379-85. doi:10.1016/j.chemosphere.2006.05.132

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.

Our content may include products that have been independently chosen and recommended by Dr. Will Cole and our editors. If you purchase something mentioned in this article, we may earn a small commission.



Evidence-based reviewed article

Dr. Will Cole, DNM, IFMCP, DC is a leading functional medicine expert who consults people around the globe, starting one of the first functional medicine telehealth centers in the world. Named one of the top 50 functional and integrative doctors in the nation, Dr. Will Cole provides a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. He is also the host of the popular The Art of Being Well podcast and the New York Times bestselling author of Intuitive Fasting, Ketotarian, Gut Feelings, and The Inflammation Spectrum.

Gut Feelings Dr. Will Cole 6

Gut Feelings

Healing The Shame-Fueled Relationship
Between What You Eat And How You Feel