Keratin
The protein that makes up 95% of every hair on your body — including your beard.
Keratin is a fibrous structural protein — the same material that forms hair, nails, and the outermost layer of skin. Understanding keratin explains why hair damage matters: once a hair leaves the follicle, it's dead protein. Nothing can 'repair' it — products can only coat, protect, and slow further damage.
- ›Makes up ~95% of every hair on the human body.
- ›Once out of the follicle, hair is dead protein.
- ›'Repair' products actually mean 'coat and protect.'
- ›Damaged keratin cannot be structurally rebuilt.
- ›Sulfur bonds in keratin give hair its strength.
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History & Origin
Keratin is the structural protein that makes up hair, nails, and the outer layer of skin — identified in the 19th century and characterized structurally in the 20th, when work on its alpha-helix earned attention alongside the earliest protein-structure research. Beard hair is roughly 90 percent keratin, cross-linked by disulfide bonds that give coarse hair its strength and stubbornness.
Uses & Benefits
- ›Forms the structural backbone of every beard and scalp hair
- ›Disulfide bonds determine whether hair is straight, wavy, or curly
- ›Hydrolyzed keratin in products temporarily patches damaged cuticle
- ›Heat, bleach, and mechanical stress break keratin bonds permanently
- ›Understanding it explains why split ends cannot be repaired, only removed
Safety & Sourcing
Hydrolyzed keratin in cosmetics is safe and well tolerated. Be cautious with salon 'keratin treatments,' some of which release formaldehyde during heat styling — a documented occupational exposure concern. Applying a keratin product does not rebuild hair; it deposits protein fragments that wash out over several washes.
FAQ
Can keratin repair split ends?+
No. It can temporarily smooth the damaged area, but once the cuticle splits the only permanent fix is trimming it off.
Do keratin products make hair stronger?+
They improve feel and reduce breakage in the short term by filling cuticle gaps. The effect washes out.
Why is beard hair coarser than head hair?+
Different cross-sectional shape and a higher density of disulfide cross-links in the keratin structure.
Found in Our Products
Related Comparisons
Sources
- Cruz, C. F. et al. (2016). Human hair and the impact of cosmetic procedures. Cosmetics.
- Robbins, C. R. (2012). Chemical and Physical Behavior of Human Hair, 5th Edition. Springer.
