Keratin
Description
Keratin is a family of structural proteins, renowned for its tough, insoluble nature. It is the principal component of the outermost layer of human skin, hair, and nails, as well as the feathers, hooves, and horns of animals. Its unique composition, rich in sulfur-containing amino acids like cysteine, allows for the formation of strong disulfide bonds, which contribute significantly to its stability and resistance to degradation. This essential protein plays a crucial role in maintaining the integrity and protective barrier function of various tissues. In the skin, keratinocytes produce keratin that forms a robust shield against environmental damage, pathogens, and water loss. For hair, keratin provides its strength, elasticity, and shape, while in nails, it forms the hard plate that protects the fingertips and toes. Keratin supplements, often derived from animal sources, are used to support the body's natural keratin production, aiming to improve the health, appearance, and strength of hair, skin, and nails. It is frequently hydrolyzed into smaller peptides for better absorption and bioavailability when taken orally, or applied topically to enhance external structures.
Sources
Human hair, skin, and nails (endogenous production)Animal sources: Feathers, wool, hooves, horns (used for supplements after processing)Foods rich in protein and sulfur-containing amino acids (e.g., eggs, fish, poultry, legumes) which support the body's natural keratin production.
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Safety & Toxicity
Goals
Hair Health
Impact
High effect
Typical dose:250–500 mg
Since hair is composed of about 95% keratin, supplementing with a bioavailable form (e.g., solubilized keratin) provides the body with the exact material needed for hair structure. Clinical studies on specific forms have demonstrated a significant reduction in hair shedding and an improvement in hair brightness and strength.
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Nail Health
Impact
High effect
Typical dose:250–1000 mg
Supplementing with solubilized keratin provides the complete profile of amino acids, including the sulfur-containing ones like cysteine, in the exact form used by the body to build nails. This can help improve nail hardness, smoothness, and reduce breakage.
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Interactions
Positive Interactions
Biotin
Biotin is essential for the body's keratin infrastructure and promotes healthy hair and nail growth, working synergistically with keratin.
Cysteine
Cysteine is a crucial sulfur-containing amino acid and a primary building block of keratin, directly supporting its synthesis and structure.
METHIONINE
Methionine is another essential sulfur-containing amino acid vital for keratin synthesis and overall hair health.
Silicon
Silicon contributes to the structural integrity of hair, skin, and nails, enhancing the benefits of keratin for strength and resilience.
Vitamin C
Vitamin C is essential for collagen synthesis, which supports the dermal layer and hair follicles where keratin is produced.
Zinc
Zinc plays a vital role in protein synthesis and cell division, which are crucial for the growth and repair of keratin-rich tissues.
Copper
Copper is involved in collagen formation and hair pigmentation, supporting healthy hair structure alongside keratin.
Collagen
Collagen provides structural support to skin and connective tissues, working synergistically with keratin for overall skin, hair, and nail health.
Horsetail
Horsetail is a natural source of silicon, which can enhance keratin's benefits for hair and nails by improving their strength.
Glutathione
Glutathione, a powerful antioxidant, can protect cells, including keratinocytes, from oxidative stress, supporting overall tissue health and keratin integrity.
Vitamin A
Vitamin A supports cell growth and differentiation, important for healthy skin and hair follicle function where keratin is produced.
Vitamin E
Vitamin E is an antioxidant that can help protect cells from damage, supporting the health of keratin-producing cells and the scalp.
Folate
Folate is involved in cell division and tissue growth, contributing to healthy hair and skin, and thus supporting keratin-rich tissues.
Iron
Iron is essential for oxygen transport to hair follicles, supporting their healthy function and efficient keratin production.
Proline
Proline, an amino acid, is a major component of collagen, which supports the dermal layers where keratin structures are formed.
Glycine
Glycine, another amino acid crucial for collagen structure, indirectly supports the environment for keratin production.
Lysine
Lysine is an essential amino acid involved in protein synthesis and collagen formation, which supports tissues containing keratin.
Vitamin B6
Vitamin B6 acts as a cofactor in amino acid metabolism, including those essential for keratin synthesis.
Vitamin B5
Vitamin B5 (Pantothenic Acid) is known to support hair strength and elasticity, complementing keratin's role.
Hyaluronic Acid
Hyaluronic Acid hydrates and provides structural support to the skin, complementing keratin's barrier function and promoting skin health.
Product stats
Price per product
Average$27.96
Median$25.31
Price per serving
Average$0.80
Median$0.75
Price per 100 mg
Average$0.26
Median$0.23
Price distribution
Price per serving distribution
Price per 100 mg
Reference amount: 100 mg
Forms
Paired ingredients
Ingredient forms
Keratin (3) 65
Keratin is a highly robust and insoluble protein that serves as the fundamental building block for hair, skin, and nails in humans and animals. It forms a protective barrier and imparts structural integrity, elasticity, and resistance to damage. In its natural, unprocessed form, it is largely impermeable and difficult for the body to absorb or utilize directly when applied topically.
Pros
- Fundamental component of hair and nails
- Provides natural strength and protection
Cons
- Limited direct bioavailability in its intact form
- Often requires processing for effective cosmetic application
Per product
Avg$25.95
Med$26.19
Per serving
Avg$0.86
Med$0.87
Per 100 mg
Avg$0.14
Med$0.13
Price distribution
Sheep's Wool (2) 15
Sheep's wool is a widely recognized natural fiber that is rich in keratin protein. While it is an abundant and common industrial source for extracting keratin that is subsequently processed into forms suitable for human use (e.g., hydrolyzed keratin), the raw wool itself is not directly used as an ingredient for hair or nail health supplements or topical applications due to its physical structure and insolubility.
Pros
- Abundant and renewable natural source of keratin
Cons
- Not bioavailable for direct human use (ingestion or topical)
- Requires extensive chemical processing to extract usable keratin
Per product
Avg$49.64
Med$49.64
Per serving
Avg$1.09
Med$1.09
Per 100 mg
Avg$0.17
Med$0.17
Price distribution
Soluble Keratin (2) 75
Soluble keratin is produced by selectively breaking some of the disulfide bonds within the keratin protein structure, typically through mild oxidation, without fully fragmenting the protein into small peptides. This modification allows it to dissolve in water, making it suitable for use in shampoos, conditioners, and nail treatments. It works primarily by adhering to the surface of hair strands and nail plates, forming a protective film that enhances shine, smoothness, and strengthens the outer layer.
Pros
- Water-soluble, easy to formulate into products
- Adheres to hair and nail surfaces, improving appearance
- Enhances shine and manageability of hair
- Provides a protective layer for nails
Cons
- Does not deeply penetrate hair or nail structures as effectively as hydrolyzed forms
- Benefits are often temporary and require continuous application
Per product
Avg$36.89
Med$36.89
Per serving
Avg$1.02
Med$1.02
Per 100 mg
Avg$0.95
Med$0.95
Price distribution
Keratin, Hydrolyzed (1) 85
Hydrolyzed keratin undergoes a chemical process (hydrolysis) that uses water and enzymes or acids to break down large keratin proteins into smaller, more bioavailable fragments (peptides) and individual amino acids. This reduced molecular size allows for greater penetration into the hair shaft and nail plate, providing deeper conditioning, repair, and strengthening from within. It is widely used in high-performance hair care products, nail treatments, and occasionally in oral supplements to support structural integrity.
Pros
- Improved penetration into hair and nails due to smaller molecular size
- Strengthens hair from within, reducing breakage and improving elasticity
- Repairs damaged hair cuticles and brittle nails
- Increases moisture retention in hair and nails
- Versatile for topical and some oral applications
Cons
- Can lead to product buildup if overused, especially in fine hair
- Typically sourced from animal byproducts (e.g., wool, feathers), which may be a concern for some users
Per product
Avg$21.36
Med$21.36
Per serving
Avg$0.35
Med$0.35
Per 100 mg
Avg$0.07
Med$0.07
Price distribution
Tibetan Wool (1) 15
Tibetan wool is a distinct type of sheep's wool known for its strong, coarse, and durable fibers, traditionally used in textiles. Like other wools, it is primarily composed of keratin protein. However, similar to general sheep's wool, in its raw fibrous state, Tibetan wool is not directly utilized for human hair or nail health benefits. Its value lies in being a specific, high-quality natural source from which keratin can be extracted and processed into more bioavailable and functional forms for cosmetic and health products.
Pros
- Specific and high-quality natural source of keratin
Cons
- Not bioavailable for direct human use (ingestion or topical)
- Requires extensive processing to extract usable keratin
Per product
Avg$6.99
Med$6.99
Per serving
Avg$0.11
Med$0.11
Per 10 mg
Avg$0.02
Med$0.02
Price distribution