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11/20/2018

Soy Can Affect Thyroid

Daily intake of soy isoflavones (as found in soy protein and soy isoflavone supplements) can affect thyroid hormone levels — even in people with normal thyroid function, according to a recent study. For details, see the "Concerns and Cautions" section of the Menopause Supplements Review and the Protein Supplements Review.
1/12/2020

Concern With Ashwagandha

Ashwagandha can increase thyroid hormone levels, resulting in thyroid toxicity, even in people without a history of thyroid disease. Read about a recent case and learn symptoms to look for in the Concerns and Cautions section of the Ashwagandha Supplements Review. Also see our Top Pick among ashwagandha supplements.
6/20/2017

Warning: Biotin Can Affect Thyroid Tests

Vitamins that contain megadoses of biotin (vitamin B7) can affect thyroid tests, according to recent studies. This can lead to an incorrect diagnosis of hyperthyroidism and improper treatment. See the "Biotin" section of the B Vitamin Supplements Review >>
9/02/2017

Ashwagandha & Thyroid Function

Ashwagandha extract improved thyroid hormone levels in men and women with subclinical hypothyroidism in a new study. See the details in the "What It Does" section of our Ashwagandha Supplements Review -- which includes our Top Pick among ashwagandha supplements.
10/29/2018

Don't Take Calcium With Thyroid Hormone

A study showed negative effects of taking calcium too soon after taking levothyroxine (Synthroid). For details on how to safely take this combination, see the update in the Concerns and Cautions section of the Calcium Supplements Review. (Also see our Top Picks for calcium.)
4/21/2013

Does Ginkgo Cause Cancer?

According to a new study from the government, animals given an extract of Ginkgo biloba for two years developed cancers of the thyroid and liver. Should you be concerned? See the "Concerns and Cautions" section of the Ginkgo Biloba Supplements Review for more information, as well our assessment of ginkgo's usefulness, and our tests of ginkgo supplements
10/24/2020

How Good Is Generic Thyroid Medication?

How well do people with hypothyroidism do on generic versions of levothyroxine (Synthroid)? We've added new information about this to our article about levothyroxine and dietary supplements.
11/05/2021

Fluoride and Hypothyroidism?

Can fluoride in toothpaste affect thyroid function? Find out what research suggests in our updated article about what to look for, or avoid, in toothpaste.