In patients with mild, active Graves' orbitopathy lasting less than seven months, selenium supplementation may be linked to better quality of life and fewer eye symptoms, but these findings are based on one study and have not been confirmed by others.

Taking selenium supplements does not lead to better quality of life for people with Graves' hyperthyroidism who do not have eye symptoms, as studies show no meaningful difference in mood or self-reported symptoms compared to taking a placebo.

There is no clear evidence that taking selenium supplements improves key outcomes for people with Graves' disease, such as reducing relapses, improving quality of life, or easing eye symptoms.

Taking selenium supplements does not keep thyroid hormone levels improved in people with Graves' disease beyond six months; after nine months, these levels return to what they were before treatment, even if supplementation continues.

Taking selenium supplements daily at 100–300 micrograms for six months may lower levels of antibodies targeting the thyroid-stimulating hormone receptor in adults with Graves' disease who are on antithyroid drugs, but this reduction does not last beyond nine months.

It is unclear whether selenium supplements help treat Graves' disease because studies have varied widely in how they gave selenium, did not measure patients' initial selenium levels, and used lab tests instead of actual health outcomes like disease remission.