Melatonin is a hormone produced by the pineal gland located deep in the center of the brain. It is produced in response to darkness and its production is inhibited by bright light. Melatonin is produced from serotonin which is produced from the amino acid tryptophan. Melatonin is responsible for the sleep/wake cycle of the body. These factors come into play in the case of night workers and shift workers as well as travelers who experience jet lag.

As melatonin production peaks in adolescence and declines with age, it is one of the factors that contribute to less quantity and quality of deep sleep in aged adults. It has also been noted that melatonin is lower in patients with coronary artery disease.

Benefits of Melatonin

There are many benefits of melatonin including:

  • Improved sleep pattern
  • Improved sleep quality and less trouble going back to sleep after waking at night
  • Increased slow wave sleep with a consequent increase in growth hormone production
  • Dreams are usually vivid and many people report dreaming as a pleasure that they have not experienced since a younger age.
  • Since melatonin is brought on by darkness and decreased by light, it may reset the sleep cycle
  • Melatonin has been shown to be a potent chemotherapeutic agent in solid tumors
  • It counteracts the effects of stress 
  • Melatonin acts as a potent antioxidant, free radical scavenger, and immunostimulant 
  • May reduce elevated cholesterol
  • Melatonin is an excellent agent for the prevention of migraines (especially cluster headaches)

Dosage

There is no standard dosage for melatonin and it is generally titrated to effect. Women are more sensitive to melatonin than men and the dose is usually started at 1 to 3 mg per day. Men require higher doses of melatonin and usually are started at 3 to 9 mg per day. Dosages larger than 10 mg per day are rarely used. The maximum dosage of melatonin is considered to be 45 mg per day. Micronized melatonin has a sustained release effect with therapeutic levels sustained for six hours in comparison with the over-the-counter products which have a sustained therapeutic effect for no longer than two hours.

When discontinuing melatonin the dosage should be cut back in increments over one to two weeks to avoid rebound insomnia. Melatonin is contraindicated in pregnancy and nursing mothers. it may be contraindicated in certain instances of autoimmune disease (multiple sclerosis), immune system cancers (lymphoma or leukemia) and possibly in some forms of a metastatic disease being treated with chemotherapy

Side Effects

Other than the desired side effect of sleepiness, one of the side effects of high dose melatonin includes a possible reduction and suppression of estrogen and testosterone. Other side effects include prolonged grogginess (usually due to too high a dose) and a change in hair color (may actually be a deeper shade and more plentiful, less gray noted). As mentioned previously, vivid dreams may occur. Usually not unpleasant, nightmares for two to three days may be one of the side effects upon initiating melatonin therapy. Adverse side effects are estimated at 1%; melatonin may have no effect in 10%.

Melatonin is extremely effective in withdrawing patients from benzodiazepines (sedatives, often used as a sleep aid) without rebound insomnia. These patients are able to use melatonin as a sleep-inducing agent rather than benzodiazepines which may produce memory loss and dependence.

There are factors which increase melatonin production:
  • Supplementation
  • Sleep
  • Exercise
Factors which decrease melatonin secretion are:
  • Cardiac and blood pressure medicines such as beta blockers, calcium channel blockers, and alpha
  • Adrenergic blockers
  • Ibuprofen and aspirin
  • Tranquilizers
  • Caffeine
  • Alcohol
  • Tobacco
  • Electromagnetic fields
  • A diet high in carbohydrates inhibits melatonin secretion