Collagen is a protein that forms the part of our nails, bones, teeth, skin and other connective tissues such as tendons, ligaments, cartilages etc. They form strong fibers in bones, thereby giving structure and strength to the body and body parts.
70% of the skin (dry mass) is collagen! 90% of bones, 85% of tendons, 70% of cartilage – all are basically made up of collagen. Our body produces collagen, however, as we age, this becomes lesser and lesser. Along with the natural process of aging, pollution, smoking etc also facilitates collagen breakdown thereby making the skin saggy, dull and dry.
It is suggested that eating collagen-rich food or supplementing the same will help in re-assimilating them thereby improving the skin, nail, bone health etc. Collagen supplementation is also advised for people suffering from arthritis (OA & RA), as it is claimed to help the body in rebuilding the damaged connective tissues much faster.
Collagen peptide, also known as hydrolyzed collagen is a widely available supplement that is readily absorbed by our body. Animal products such as bone broth, chicken and pork skin, gelatin etc are very high in collagen, however, their absorption rate is inferior to the hydrolyzed collagen (collagen peptide)
It is unclear and not proven conclusively if eating collagen-rich food / supplementing will help in rebuilding the connective tissues of the target organ that we intend to rebuild. i.e , if a person is having arthritic knee pain, it is unclear if collagen peptide will help in improving the connective tissues of the knee itself!
Long story short – there is only inconclusive evidence in the efficacy of targeting a particular area with collagen supplements. However, they are devoid of any negative side effects – so you might as well try if it helps!