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HFL Health Findings Lab™

Selenium

A potent trace mineral functioning as a critical antioxidant and an essential cofactor for the activation of thyroid hormones.

Evidence-Based
Fact-Checked
Updated: Sep 23, 2026
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Clinical Profile

Quick Reference

Scientific Rating
4.9
/ 5.0
Standardized Form
L-Selenomethionine or Selenium-Enriched Yeast

Selenium is a trace mineral that acts as a structural component of over 25 functional selenoproteins in the human body. Clinically, its two most vital roles are serving as a cofactor for glutathione peroxidase (a master cellular antioxidant enzyme) and for iodothyronine deiodinases (the enzymes responsible for converting the inactive thyroid hormone T4 into the metabolically active T3). Supplementation is widely utilized to support systemic immune defense and protect thyroid tissue from oxidative stress and auto-antibodies.

Clinical Summary

Strongly supported by clinical trials for reducing thyroid auto-antibodies in Hashimoto's thyroiditis and supporting healthy immune and metabolic function.

Dosage Guidelines

55mcg daily for baseline health; 100mcg to 200mcg daily is often used in clinical protocols for autoimmune thyroid support.

Safety & Side Effects

Has a narrow therapeutic window. Chronic excessive intake (selenosis) can cause hair loss, brittle nails, a garlic odor on the breath, and neurological damage.

Known Interactions

No major drug interactions at standard doses, but should be balanced carefully with iodine intake for optimal thyroid function.

Scientific References

Medical Disclaimer

The information provided in this clinical review is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.

*These statements have not been evaluated by the Food and Drug Administration (FDA). This product or ingredient is not intended to diagnose, treat, cure, or prevent any disease.

Always consult your physician or other qualified health provider with any questions you may have regarding a medical condition, or before beginning any new diet, fitness, supplement, or treatment regimen, especially if you have pre-existing medical conditions or are taking prescribed medications.

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