NutriStack
Methimazole and Selenium, a synergy.
Selenium has been studied as an add-on to methimazole in Graves' disease. Some smaller trials suggest improved antibody or early biochemical measures, while larger and selenium-sufficient cohorts show little or no benefit for remission or quality of life. This is a possible adjunctive effect, not a replacement for antithyroid medication.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Methimazole and Selenium
- Pair type
- Synergy
- Evidence (highest tier)
- Moderate
- Source citations
- 4 sources
- Stack Score effect
- +2 to your Stack Score (per scored synergy row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Synergy · Moderate evidence
Synergy
What is happening. Selenium has been studied as an add-on to methimazole in Graves' disease. Some smaller trials suggest improved antibody or early biochemical measures, while larger and selenium-sufficient cohorts show little or no benefit for remission or quality of life. This is a possible adjunctive effect, not a replacement for antithyroid medication.
Mechanism. Selenium is required for selenoproteins such as glutathione peroxidases and deiodinases, which participate in thyroid redox balance and thyroid hormone metabolism. Its potential benefit during methimazole therapy appears related to oxidative stress and autoimmune activity rather than methimazole pharmacokinetics.
Recommendation. Do not use selenium instead of methimazole. If your clinician recommends selenium, keep the dose in a standard supplemental range and avoid high-dose long-term use unless specifically monitored.
Sources (4)
- Leo M, Bartalena L, Rotondo Dottore G, Piantanida E, Premoli P, Ionni I, Di Cera M, Masiello E, Sassi L, Tanda ML, Latrofa F, Vitti P, Marcocci C, Marino M. Effects of selenium on short-term control of hyperthyroidism due to Graves' disease treated with methimazole: results of a randomized clinical trial. J Endocrinol Invest. 2017;40(3):281-287. PMID 27734319
- Kahaly GJ, Riedl M, Konig J, Diana T, Schomburg L. Double-Blind, Placebo-Controlled, Randomized Trial of Selenium in Graves Hyperthyroidism. J Clin Endocrinol Metab. 2017;102(11):4333-4341. PMID 29092078
- Xu B, Wu D, Ying H, Zhang Y. A pilot study on the beneficial effects of additional selenium supplementation to methimazole for treating patients with Graves' disease. Turk J Med Sci. 2019;49(3):715-722. PMID 31023005
- Cramon PK, Winther KH, Boesen VB, Larsen CB, Bonnema SJ, Bjorner JB, et al. Selenium supplementation in individuals with newly diagnosed Graves' hyperthyroidism: a double-blind, multi-centre RCT. Eur Thyroid J. 2026;15(1). PMID 41384622
Stack Score
How this pair moves the number.
Effect on the composite score
If both Methimazole and Selenium are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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