Kelp is a natural source of Iodine and other rich minerals. We use the thickest part of the plant, the base known as the "fronds" or root of the plant which is the most nutrient dense part of the plant. The root is the most fibrous containing 20x more nutrients than the leaves. Our kelp is harvested in regenerative ocean farms off the coast of Hokkaido, Japan and is done seasonally to protect the natural ecosystem of the ocean and naturally allow for regrowth. Kelp extract has been shown to naturally aid in regulating thyroid function and hormonal balance, supports healthy immune function. Iodine: 1500MCG Magnesium: 4MG Fucoidan: 29MG If you are taking any thyroid medications, please consult your doctor before consuming this supplement. Learn more about Iodine, recommended daily amounts and health effects from NIH here.