How to Choose the Best Iodine Supplement for Thyroid Support

Written by: Tennant Products Editorial Team
Reviewed by: Patsy Scott, CHN (Certified Holistic Nutritionist)
Last Updated: February 2026

TL;DR

• Iodine is required for normal thyroid hormone production and overall metabolic health.
• Many modern diets provide inconsistent iodine intake, especially if iodized salt and seafood are limited.
• The best iodine supplements provide both iodine and potassium iodide.
• Some formulas include supportive nutrients such as selenium and zinc.
• Lugol’s iodine supplements are a traditional option that provide both iodine and iodide.
• Always consult a qualified healthcare professional before supplementing, especially if you have a thyroid condition or are pregnant.

Why Iodine Matters for Thyroid Function

Iodine is an essential trace mineral. The body cannot produce it, so it must come from food or supplementation.

The thyroid gland uses iodine to produce the hormones T3 and T4. These hormones regulate metabolism, energy production, temperature regulation, and many other processes. Without adequate iodine intake, normal thyroid hormone production cannot occur.

Beyond thyroid function, iodine is present in other tissues, including breast tissue, reproductive organs, and parts of the digestive system. For this reason, iodine supplements are often discussed in broader metabolic and endocrine health conversations.

Why Some People Consider Iodine Supplements

Certain lifestyle and dietary patterns may reduce iodine intake, including:

• Limited seafood consumption
• Use of non-iodized sea salt
• Plant-based diets with minimal iodine-rich foods
• Reduced dairy intake
• Living in regions with lower iodine soil content

In addition, some environmental compounds such as fluoride and bromide can compete with iodine in the body. This does not mean everyone is deficient, but it explains why some practitioners discuss iodine intake more frequently.

If someone suspects low iodine intake, testing and professional evaluation are recommended before beginning supplementation.

What to Look for in Good Iodine Supplements

Not all iodine supplements are formulated the same way. Understanding the differences can help you choose more confidently.

1. Iodine and Potassium Iodide

The body utilizes iodine in more than one form. Traditional Lugol’s iodine contains both elemental iodine and potassium iodide. Many practitioners prefer formulas that include both forms because different tissues may utilize iodine differently.

When comparing good iodine supplements, check whether the label lists both iodine and potassium iodide.

2. Appropriate Dosage

The RDA for iodine is 150 microgram per day for most adults but this is the absolute minimum your body needs. In fact every cell in you body needs Iodine. 

Experts like David Brownstein, M.D. author of Iodine: Why You Need It, Why You Can't Live Without it, suggest higher amounts are necessary for optimal health, sometimes up to 50mg/day for specific conditions.  Many well know practitioners and health experts like Dr. Andrew Huberman, and Lynne Farrow, author of The Iodine Crises are recommending supplement with higher doses of Iodine than the RDA states. Dr. Tennant's Lugol's Iodine offers a higher dose of Lugol's Iodine solution (5mg Iodine and 7.5mg Potassium Iodide) that aligns with current experts in Iodine supplementation suggestions. 

Look for clear labeling and transparent dosage information. Avoid products that make broad claims without context. If unsure, consult a qualified provider before choosing a dose.

3. Supportive Nutrients

Some iodine supplements include co-factors such as:

• Selenium
• Zinc
• Vitamin C
• B vitamins
• Magnesium

Selenium in particular plays a role in thyroid hormone metabolism. While not everyone requires a combined formula, some people prefer a comprehensive approach.

Lugol’s iodine supplements are available in both liquid and capsule formats. Some capsule versions include supportive nutrients alongside iodine and iodide.

4. Delivery Method: Capsules vs Iodine Drops

Iodine drops provide flexibility in dosing and are commonly referred to as Lugol’s iodine liquid. They allow adjustable intake but typically do not include additional nutrients.

Capsules offer convenience and consistent dosing. When comparing best iodine supplements, consider which format aligns with your routine and comfort level.

Both formats can be effective when used appropriately.

It’s like your daily nutrient toolkit in one easy step.

A Quick Summary

How to Take Lugol's Iodine

• Take it in the morning with food and a full glass of filtered water.
  

• Avoid chlorinated water since it blocks iodine.
  

• Separate it from probiotics by 2 to 3 hours.
  

• Check with your provider if you have thyroid autoimmunity or are pregnant.
  

How to Identify the Best Iodine Supplements for Your Needs

When evaluating the best iodine supplements, consider:

• Transparent labeling
• Clear dosage information
• Inclusion of both iodine and iodide
• Third-party testing or quality assurance
• Professional guidance or clinical backing

Avoid exaggerated marketing language such as “cure,” “guaranteed,” or “detox.” High-quality iodine supplements focus on supporting normal physiology, not promising dramatic outcomes.

About Lugol’s Iodine Supplements

Lugol’s iodine is a traditional formulation that combines elemental iodine and potassium iodide in water. It has been used historically in clinical settings and remains a common choice among practitioners.

Modern Lugol’s iodine supplements are available in liquid iodine drops and capsule forms. Some capsule formulations include other nutrients that support thyroid hormone metabolism.

As with all supplements, individual suitability depends on health status, diet, and medical history.

How to Take Iodine Supplements Safely

General considerations include:

• Take with food unless otherwise directed
• Use filtered water if possible
• Separate from probiotics if advised by your provider
• Consult a healthcare professional if you have autoimmune thyroid disease, are pregnant, or are breastfeeding

Iodine supplementation is not appropriate for everyone. Personalized guidance is recommended for anyone with thyroid disorders.