Independent reviews · Updated weekly Editorial & affiliate disclosures
HFL Health Findings Lab™

Keratin

A highly durable structural protein that forms the primary matrix of the epidermis, hair, and nails.

Evidence-Based
Fact-Checked
Updated: Sep 16, 2026
Share this ingredient:
Clinical Profile

Quick Reference

Scientific Rating
4.4
/ 5.0
Standardized Form
Solubilized Keratin (e.g., Cynatine HNS)

Keratin is incredibly rich in sulfur-containing amino acids, particularly cysteine. These sulfur atoms form robust disulfide bridges, granting hair and nails their mechanical strength and resistance to breakage. Because native, intact keratin is completely indigestible to humans, clinical dietary supplements utilize solubilized or hydrolyzed keratin to deliver a highly bioavailable amino acid profile tailored specifically to epidermal appendages.

Clinical Summary

Clinically supported for significantly reducing hair shedding, enhancing hair tensile strength, and improving the structural integrity of brittle nails when consumed orally in its solubilized form.

Dosage Guidelines

Typically dosed at 500mg daily of patented solubilized keratin.

Safety & Side Effects

Generally well tolerated. Rare reports of mild gastrointestinal fullness or discomfort.

Known Interactions

No known interactions.

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.

Share this ingredient:

Get new reviews in your inbox — weekly, never spammy.

Join our community of readers who use Health Findings Lab to cut through supplement marketing noise.