The Claim

In adults with Hashimoto's thyroiditis who are not selenium deficient, selenium supplementation has no effect on reducing thyroid-stimulating hormone (TSH) levels or preventing progression to overt hypothyroidism, and may lead to an increase in TSH levels over time.

Source: Clinical Outcomes of Selenium Supplementation in Hashimoto's Thyroiditis Without Selenium Deficiency: A Large‐Scale Retrospective Cohort Study

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
59score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

For adults with Hashimoto's thyroiditis who have normal selenium levels, taking selenium supplements does not lower thyroid-stimulating hormone (TSH) or stop the condition from worsening to overt hypothyroidism, and may cause TSH levels to rise over time.

See the scientific wording

In adults with Hashimoto's thyroiditis not deficient in selenium, selenium supplementation does not reduce thyroid-stimulating hormone (TSH) levels or prevent progression to overt hypothyroidism, and may even elevate TSH over time, contradicting the hypothesis that selenium improves thyroid function.

What the research says

1 study
  1. Study: Clinical Outcomes of Selenium Supplementation in Hashimoto's Thyroiditis Without Selenium Deficiency: A Large‐Scale Retrospective Cohort Study

    In people with Hashimoto's who aren't low in selenium, taking selenium supplements didn't help their thyroid—it actually made their thyroid markers worse and raised their risk of other autoimmune problems.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

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