Keratin is a protein produced within the body to support the structure of skin, hair and nails. Poor diet and stressful lifestyles can lead to lower levels of keratin, resulting in a supplement being needed. Low levels of keratin show in dry wrinkled skin, brittle nails and thinning hair. You can lose keratin from the hair easily, from dyeing and processing hair colourants, sun damage and chemical treatments. The more keratin found within the hair follicles, the healthier and thicker the hair will look.

Keratin is also largely responsible for making skin strong, waterproof, supple, and flexible. Skin strength and resistance to tearing and penetration come from an abundance of tough, but flexible fibres of keratin in the epidermis, the outer layer of the skin. Keratin cells and fibres also maintain the moisture content of the skin by providing a waterproof yet water-retaining barrier.

Keratin has been added to health and beauty products for many years, while supplements are new to the industry. Years of research has led to a process that makes keratin absorbable within food supplements. This form of keratin, called Cynatine is now found within many beauty formulas and has been shown to improve the health and appearance of skin, hair and nails.


A 2014 randomized controlled trial found that the same keratin formulation was effective for decreasing the rate and amount of hair loss and improving the strength and appearance of nails in adult women.10

Subjects were women between 40 and 71 years old who had clinical signs of damaged hair and nails. They took two capsules of solubilized keratin or a placebo daily for 90 days. By day 90, the researchers observed the following improvements:

  • 1% subjective improvement in hair appearance
  • 9% improvement in hair strength
  • 2% increase in hair follicles in the growth phase (the placebo group had no significant increase)
  • 47% reduction in the number of hairs that could be removed from the scalp in a hair-pull test, an evaluation in which 20 to 60 hairs are grasped between the fingers and firmly tugged away from the scalp to see how many can be removed

At the structural level, the amino acid composition of hair protein changed favourably in the supplemented group.10 By day 90, all four amino acids tested had a statistically significant increase showing the bioavailability of solubilized keratin.

Nail parameters were also significantly improved in the test group.10 Supplemented subjects showed an 87.5%improvement in the tendency of their nails to break, compared with 28.5% in the placebo group.

Five additional nail health parameters showed significant improvements for the supplemented group compared with baseline:

  • Hardness improved 50%
  • Resistance to bending and breaking increased 54.2%
  • Maintenance of overall nail integrity improved 33.2%
  • Nail smoothness increased 37.5%
  • The white, or natural, appearance of the nail improved 20.8%