Top 7 Iodine Supplements for Thyroid Health in the USA - 2026

Life Extension Sea-Iodine delivers a sea-derived 1000 mcg dose positioned for consumers who want a reliable mid-to-high iodine maintenance product; it stands out for consistent dosing and brand recognition in thyroid-support formulations. Compared with very high-dose therapeutic tablets like Optimox Iodoral, Sea-Iodine is more suitable for routine supplementation, and it typically costs less per dose than specialized professional formulas while offering a higher single-dose iodine content than many kelp products.

NOW Foods Kelp is a budget-friendly, whole-seaweed option providing a lower 325 mcg iodine dose that appeals to price-conscious consumers seeking natural kelp sources. Technically simpler than multi-nutrient or pharmaceutical-style products on this list, it offers flexible dosing at a low cost per capsule but supplies less iodine per unit than Life Extension, Nature's Way, or the high-dose Iodoral, making it a maintenance-oriented choice.

Thorne Iodine & Tyrosine is a cutting-edge supplement that combines iodine with the amino acid tyrosine to support thyroid health and overall energy levels. What distinguishes this product is its well-researched formulation that addresses both iodine deficiency and its role in hormone synthesis. Thorne prides itself on using clean, high-quality ingredients, and their products are often trusted by healthcare professionals. This dedication to quality and efficacy makes it a leader in the health supplement industry.

Terry Naturally Thyroid Care Plus differentiates itself as a targeted combination formula that pairs iodine with supportive cofactors (selenium, zinc and other nutrients) to address thyroid-support needs holistically rather than as a single-ingredient iodine supplement. While it is usually pricier per mg of iodine than standalone kelp or iodide products, its technical advantage is the complementary nutrient profile that can reduce the need to buy separate supplements compared with single-ingredient options like NOW or Life Extension.

Optimox Iodoral is the market leader for high-dose iodine therapy, offering a 12.5 mg tablet intended for repletion strategies where higher, consistent iodide/iodine intake is required; its technical strength is pharmaceutical-style dosing and tablet stability. Financially, it is cost-effective for short-term therapeutic courses because fewer tablets are needed per dose compared with lower-strength products, but its potency and intended use set it apart from milder maintenance formulas like Life Extension or kelp-based supplements.

Nature's Way Kelp provides a mid-range 600 mcg natural iodine option, balancing the whole-food appeal of kelp with a higher per-capsule iodine level than many budget kelp products. It sits between NOW Foods (lower dose) and Life Extension (higher sea-iodine dose) on potency and typically offers competitive pricing and sustainable-harvest marketing, making it a pragmatic choice for those wanting a stronger kelp-based supplement without moving to synthetic high-dose tablets.