The pineal gland, which produces melatonin to regulate sleep, can develop calcium deposits (calcifications) over time. Researchers aren’t certain why this happens, though aging, metabolic activity, ...

Prostaglandins are hormone-like substances. Different tissues in the body can release prostaglandins, including the skin, stomach, and lungs. Having an appropriate amount of this substance is ...

Melanin is a substance present in the skin that produces pigment. Each person has a different amount of melanin in their skin. The variation of melanin is due to genetics and other factors. In this ...