People mainly take Selenium for energy, hormones, skin & hair. Based on 105 first-hand reports and 105 meta-analyses & systematic reviews in the medical literature. Ranked #458 of 1,974 overall.
Of reports that state an outcome, 64% are positive.
Of the people who reported each effect, the share who said it got better.
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: Conclusions: In people with HT without THRT, selenium was effective and safe in lowering TSH, TPOAb, and MDA levels. Indications for lowering TPOAb were found independent of THRT.
PubMed 38243784 ↗Conclusion: Selenium is effective in reducing CAS and improving the palpebral aperture and GO-QOL in patients with GO. Additionally, it is safe and has promising therapeutic implications. However, further research is needed to validate its long-term efficacy and safety.
PubMed 39138905 ↗Conclusion: The use of high-dose selenium might be associated with a beneficial effect on 28-day mortality in critically ill patients. Nevertheless, the use of selenium as adjuvant therapy needs further evaluations.
PubMed 24135013 ↗Conclusion: Supplementation with selenium significantly reduces the incidence of preeclampsia. However, more prospective clinical trials are required to assess the association between selenium supplementation and preeclampsia and to determine the dose, beginning time, and duration of selenium supplementation.
PubMed 26516080 ↗As stated by users — not a recommendation. Follow the label or your doctor.
How often each side effect came up across all reports.
Verbatim quotes, shortened only — each links to the original discussion.
“Can we take zinc and seleniumn together or not? I heard once that they are antagonists”
“Been taking 10-30mg Iodine with 200ug selenium, 1-3g magnesium and 1g C vit for months.”
“Selenium for the liver/heart”
“some fish oil, vitamin e, zinc, and selenium”
“I'd be cautious with larger doses of selenium. Even 200mcg/day is associated with increased incidence of type 2 diabetes”
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 2, 2026. How we rate