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How to Take Kelp Powder

Kelp is a form of seaweed that is often used as an herbal remedy for obesity and hypothyroidism. Kelp supplements are available in pill, tincture and powder form. Kelp is high in iodine, which contributes to healthy thyroid function, but different brands of kelp powder can have varying levels of iodine. Additionally, too much iodine may actually hinder thyroid function. Adults should have 120 to 150 mcg, pregnant women should have 175 mcg and breastfeeding women should have 200 mcg of iodine per day.

Consult your physician before taking kelp as a supplement, especially if you have a known thyroid condition.

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Purchase kelp powder that is packaged in a container with a scoop rather than in bulk. Bulk kelp powder can have varying levels of iodine, and it is difficult to determine proper dosing. Packaged kelp powder with a pre-measured scoop allows you to have greater control over your dosing.

Add the manufacturer’s recommended amount to a liquid, such as juice or soup. You can also blend it into a smoothie. Stir well to thoroughly dissolve the kelp powder.

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Take no more than the manufacturer’s recommended amount. Kelp powder contains arsenic in addition to iodine. Too much kelp powder can cause arsenic poisoning.

Use kelp powder for no more than two weeks at a time, according to Linda B. White, M.D., author of “The Herbal Drugstore.” Allow your system to go without for at least two weeks before taking the kelp again.


Do not take kelp or other iodine supplements if you are taking medication for a thyroid condition.