Melatonin is a hormone found naturally in the body. Melatonin used as medicine is usually made synthetically in a laboratory. It is most commonly available in pill form, but melatonin is also available in forms that can be placed in the cheek or under the tongue. This allows the melatonin to be absorbed directly into the body. Some people take melatonin by mouth to adjust the body’s internal clock. Melatonin is most commonly used for insomnia and improving sleep in different conditions. For example, it is used for jet lag, for adjusting sleep-wake cycles in people whose daily work schedule changes (shift-work disorder), and for helping people establish a day and night cycle.
Melatonin’s main job in the body is to regulate night and day cycles or sleep-wake cycles. Darkness causes the body to produce more melatonin, which signals the body to prepare for sleep. Light decreases melatonin production and signals the body to prepare for being awake. Some people who have trouble sleeping have low levels of melatonin. It is thought that adding melatonin from supplements might help them sleep.
There are actually two things going on that make sleep such a potent antioxidant:
Melatonin is essentially the mitochondrial antioxidant, and ancient one at that.
“Melatonin may be considered as a mitochondrial antioxidant because it not only directly scavenges and indirectly neutralizes free radicals, but it also reduces radical generation in mitochondria, via a phenomenon known as radical avoidance. To achieve radical avoidance, melatonin accelerates the electron flow through the [electron transport chain] and slightly activates the [mitochondrial permeability transition pore]. This may explain why melatonin is more protective of mitochondria against oxidative stress than other antioxidants. Studies have documented that melatonin restores the mitochondrial functions in aged animals and in animals with different pathological conditions.”
Melatonin is quite possibly nature’s most versatile biological signal. It has been found in all major types of organisms — not just animals, but also plants, algae, fungi, and even bacteria. In fact, melatonin is believed to have appeared over 3 billion years ago in photosynthetic bacteria, where it protected against oxidative stress.