Collagen is the body’s main structural protein. Collagen makes up 70% of skin and gives skin both strength and elasticity. Collagen forms 30% of bone and gives bones the flexibility they need to withstand impact. The collagen fibers in bone are the binding sites for calcium as well as all bone minerals. Collagen is the major component of fascia, cartilage, ligaments, and tendons. Collagen production begins decreasing at age 18. By the age of 40, the decrease is about 1% per year. For women, the decline equates to a loss of 7% of skin thickness every 10 years. Rejuvenate activates your body’s natural collagen-producing cells.