Melatonin is a hormone which is secreted by the pineal gland at the base of your brain. Maximum secretion is around 2AM & stops at sunrise. Since melatonin is only secreted while you are sleeping, yet melatonin is needed for sleep, you can see how insomnia begets more insomnia. Normal nighttime production is 5-25 mcg. Secretion of melatonin declines with aging & is thought to be decreased by up to 75% by age 70. This decline is one of the many changes & depletions furthering the aging process.
Most people only think of melatonin in relation to sleep, but its effects & benefits are far-reaching. One of melatonin’s most important effects on other hormones is to enhance the production of youth promoting growth hormone (GH). The aging process is associated with declining growth hormone. A study showed melatonin administration doubled (GH) production in men. With a decline in growth hormone we start to lose muscle mass, strength, energy, skin tone, hair, hearing, etc. & disease risk increases.
Melatonin has wide-spectrum antioxidant, anti-inflammatory, immune boosting, hypotensive, cell communication enhancing, cancer suppressing, brown fat-activating, and blood-lipid-lowering effects, and thereby protects tissues from a variety of insults. Melatonin is so important to your immune system that depleted levels cause atrophy of the thymus gland, an important part of your immune system.