Collagen

Collagen is a naturally-produced protein found in connective tissues of the body. Essentially the glue that holds the body together, its strong, flexible fibres weave throughout the body for strength and support. It is mostly found in fibrous tissues like tendons, ligaments and skin, and is also abundant in the cornea, bones, blood vessels, cartilage, intervertebral disc and the digestive tract.
The body’s natural collagen production slows after the age of 25. After this, most people see a 1.5 percent reduction in their natural collagen levels each year, resulting in tell-tale signs like wrinkly skin, thin hair, brittle nails, joint swelling and discomfort, muscle ache, toothache and headaches.

When the body receives collagen, it distributes it to where it's needed. Among many other benefits, collagen supplements support:
Improved tendon and joint flexibility and strength
Strong teeth, hair and nails
Recovery from injuries and muscle repair
Skin texture, firmness and hydration