Human hair is made up of 95% keratin, a fibrous, helix shaped protein that also forms skin and nails. In one study, healthy women were given 500mg keratin, plus vitamins and minerals, and saw improvement in hair quality. Compared to placebo, study participants experienced a significant improvement (46%) in hair fallout compared to baseline, 5.9% increase in hair strength, and a 47% improvement in appearance after 90 days. Overall, the combination supplement, including keratin, showed a 12.5% reduction in hair loss over placebo at Day 30 and a 34.5% and 34.4% reduction at Days 60 and 90, respectively (1).

Like hair, nails are made up primarily of hard and soft keratin proteins. A study that supplements healthy women with 500mg keratin, vitamins and minerals, found that women taking keratin, vitamins and minerals showed statistically significant improvement in nail strength and appearance at 90 days (1).

Skin is made up of three layers: epidermis, dermis and hypodermis. The epidermis is the top layer of the skin that can be seen and touched. Keratin is found inside of the skin cells that make up the epidermis. A study done on healthy women found that supplementing with 500mg keratin, vitamins and minerals could improve skin appearance. Study participants were evaluated on skin parameters including moisture, elasticity, wrinkles, protein content and appearance. Results showed significant improvements in skin moisture, skin elasticity, wrinkle reduction, skin compactness and skin appearance compared to placebo after 90 days. After 90 days, skin moisture was significantly increased by 11% with almost 80% of subjects taking keratin showing an increase in skin moisture. Skin elasticity also significantly increased after 90 days of supplementation, with participants showing a 7.2% improvement and 87% overall saw an increase in skin elasticity. Appearance of wrinkles were measured quantitatively and also qualitatively by a certified Dermatologist. Using a quantitative measure, wrinkle depth decreased by about 12% from baseline after 90 days, and the dermatologist evaluation showed a 58% improvement in the appearance of wrinkles after 90s of supplementation (1).