Selenium (Thyroid) Research & Evidence

SupplementScience.ai Editorial Team·Evidence-Based Supplement Research

Published Mar 11, 2026

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Evidence Level

Strong

Selenium has one of the strongest evidence bases among minerals for thyroid support. The landmark Gartner et al. (2002) RCT demonstrated a 21% reduction in TPO antibodies with 200mcg selenomethionine daily in Hashimoto's patients. The EUGOGO trial (Marcocci et al., 2011, NEJM) showed selenium improved outcomes in mild Graves' orbitopathy. Negro et al. (2007) demonstrated reduced postpartum thyroiditis in TPO-antibody-positive pregnant women. A 2010 Cochrane review acknowledged the evidence but called for larger, longer trials to confirm clinical endpoints beyond antibody reduction.

Evidence by Condition

Condition	Studied Dose	Evidence
Hashimoto's thyroiditis	200mcg selenomethionine daily	Strong
General thyroid support	100-200mcg daily	Strong
Graves' orbitopathy	200mcg daily (100mcg twice daily)	Strong
Postpartum thyroiditis prevention	200mcg daily	Moderate

Full Selenium (Thyroid) Guide

References

Gärtner R, Gasnier BC, Dietrich JW, Krebs B, Angstwurm MW (2002). Selenium supplementation in patients with autoimmune thyroiditis decreases thyroid peroxidase antibodies concentrations. Journal of Clinical Endocrinology & Metabolism. DOI PubMed
Marcocci C, Kahaly GJ, Krassas GE, Bartalena L, Prummel M, Stahl M, Altea MA, Nardi M, Pitz S, Boboridis K, Sivelli P, von Arx G, Mourits MP, Baldeschi L, Bencivelli W, Wiersinga W (2011). Selenium and the course of mild Graves' orbitopathy. New England Journal of Medicine. DOI PubMed
Negro R, Greco G, Mangieri T, Pezzarossa A, Dazzi D, Hassan H (2007). The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies. Journal of Clinical Endocrinology & Metabolism. DOI PubMed