Melatonin: More than a Sleep Aid

What is Melatonin?

melatonin and sleepingMelatonin is a hormone primarily released by the pineal gland at night, and has long been associated with control of the sleep–wake cycle. It is typically taken at night before bedtime as a supplement. In addition to melatonin’s application as a sleep aid, this supplement can also be used for lowering eye pressure — such as in cases of open angle glaucoma or glaucoma suspects.  Research shows melatonin may also protect the eye’s macula by supporting the functioning of the mitochondria, the tiny “batteries” in each cell. Alzheimer’s disease appears to be linked to poor quality sleep and melatonin production; therefore, melatonin may prove to be a useful supplement and research is underway. Keep reading for details plus information about supplements available on this website.

What Can Melatonin Help?


Melatonin is best known for helping us get to sleep. It is secreted by the pineal gland, acting as the body’s biochemical signal of biological darkness. In other words, our bodies biochemistry signals that you are ready for sleep. Blue light suppresses production of melatonin 1 to a surprisingly profound degree.2

If you are exposed to blue light right before bedtime (e.g. checking your email one more time), it throws off the internal rhythm that allows you to get adequate sleep. Nearly 75% of children now use some sort of electronic device in their bedroom. The use of these devices markedly impacts sleep quality, which in turn, contributes to social adjustment problems, behavioral problems in school and at home, and surprisingly, weight gain.

Similarly, it has been found that sleeping in a room that is not dark, also disrupts sleep, or makes it less effective in reducing fatigue and alleviating the accumulated stress of the day. Most studies found that exposure to light in the room, during sleep, reduces melatonin production by 50%.

While most research on the effects of smartphones on sleep and circadian rhythms have involved children and teens, adults are also adversely impacted. One Flemish study included more than 800 adults, 50% of whom owned smartphones, and 60% of whom used their smartphone during the night. Nighttime phone use and texting at night markedly increased how long it took to fall asleep and markedly decreased the quality, duration, and efficiency of sleep. In younger adults, nighttime electronic-device use was tied to more fatigue and later rising time. In older adults, it was associated with shorter sleep duration and earlier rise time.3

Recommended dosage is 1mg–3mg before bedtime.

Supports the Immune System

Melatonin plays a dual role in supporting the immune system, at least partially because it helps promote glutathione levels in the body, an essential master antioxidant.  It communicates with the immune system and influences white blood cells to fight infections and inflammation. Lowered levels of the super antioxidant glutathione4 are present in “clinical conditions like autoimmune disorders, neurological disorders, diabetes, and microbial infections”5 which are characterized by white blood cells. In other words, melatonin protects white blood cells from free radicals by supporting normal glutathione levels.

Lowers Eye Pressure

Intraocular pressure (IOP) is usually lowest at night, which is also when natural levels of melatonin are near their high in the circadian cycle. IOP is highest in the morning when melatonin is low. There seems to be a correlation between IOP and melatonin; supplementing with melatonin may lower IOP. 6 7

Protects the Macula

Melatonin also protects the macula, the center part of the retina which is responsible for your central vision needed for close-up work such as reading. Age-related macular degeneration (AMD) is the loss of central vision and is caused by deterioration of the macula. A combination of melatonin (3mg), zinc (8.7mg), and selenium (50 mcg), taken before bedtime, helps stabilize AMD with some remarkable improvement in the fundus of the eye after taking the combination for 6 months. 8 9

Supports Mitochondrial Functioning

A 2020 review proposed that melatonin protects the macula by supporting mitochondrial function. Mitochondria are the “energy-producers” of cells, and are essential for cellular health. As we age DNA repair functions, antioxidant activity, and lack of mitochondrial renewal lead to significant increase in free radicals. These changes cause inflammation and premature cell death in the retinal pigmented cells that protect the retina and macula.10

Helps Night Vision

Photosensitive retinal ganglion cells (melanopsin-expressing retinal ganglion cells “mRGC”) release melanopsin which affects pupil dilation and adaption and suppresses melatonin11 between dark and bright light (such as recovery after glare of an oncoming car headlights).

Melanopsin’s presence in retinal nerve cells is linked to reduced levels of melatonin and the relationship may be involved in poor night vision. At night, melatonin is secreted by rod and cone photoreceptors, functioning as a dark adaptive signal and it, in turn, modulates these photoreceptors.12

Aids Alzheimer’s Disease Issues

Melatonin may be a useful agent in preventing and treating Alzheimer’s disease (AD).  Classic markers of AD include the build-up of beta amyloid plaque, as well as excessive tau protein resulting in neurofibrillary fiber build-up.13

The production of melatonin runs parallel to AD progression. Quality of sleep is dependent upon melatonin, and it appears to be a safe and effective treatment for AD patients with sleep dysfunction.14 Melatonin stimulates non amyloidogenic processing and inhibits beta amyloid precursor protein processing which culminates in amyloid aggregates – a neuroprotective function in AD pathology.15 It decreases AD-like tau hyperphosphorylation, protects the cholinergic system and is anti-inflammatory. It may be a useful agent in preventing and treating AD.16 Weak melatonin signaling (melatonin receptor type 1A gene) appears to contribute to the cascade of AD pathology.17

Recommended Products

NEWDr. Grossman’s REM Sleep Support (sublingual) Formula – great sublingual night-time formula with melatonin, and a range of other nutrients to promote a good night’s sleep.

ACG Glutathione EXTRA STRENGTH Spray 2oz. – 6-12 sprays by mouth 2 times per day.

Melatonin (50) MZS 60 x 3mg Tabs, Dr. Pierpaoli –  50 3mg tabs with zinc and selenium

  1. Gooley JJ, Chamberlain K, Smith KA, Khalsa SB, Rajaratnam SM, et al. (2011). Exposure to Room Light before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans. J Clin Endocrinol Metab. Mar;96(3):E463-72.
  2. Vartanian GV, Li BY, Chervenak AP, Walch OJ, Pack W, et al. (2015). Melatonin Suppression by Light in Humans Is More Sensitive Than Previously Reported. J Biol Rhythms. Aug;30(4):351-4.
  3. Exelmans L, Van den Bulck J. (2016). Bedtime mobile phone use and sleep in adults. Soc Sci Med. Jan;148:93-101.
  4. Glutathione is actually the antioxidant found in greatest quantity in the brain and found to be deficient in the brains of Alzheimer’s and Parkinson’s patients.
  5. NaveenKumar SK, Hemshekhar M, Jagadish S, Manikanta K, Vishalakshi GJ, et al. (2020). Melatonin restores neutrophil functions and prevents apoptosis amid dysfunctional glutathione redox system. J Pineal Res. Oct;69(3):e12676.
  6. Samples, J.R., Krause, G., Lewy, A.J. (1988). Effect of melatonin on intraocular pressure. Curr Eye Res. Jul;7(7):649-53.
  7. Alkozi HA, Navarro G, Franco R, Pintor J. (2020). Melatonin and the control of intraocular pressure. Prog Rentin Eye Res. Mar;75:100798.
  8. Stefanova NA, ZHdankina AA, Fursova AZ, Kolosova NG. (2013). Potential of melatonin for prevention of age-related macular degeneration: experimental study (in Russian). Adv Gerontol. 2013;26(1):122-9.
  9. Yi C, Pan X, Yan H, Guo M, Pierpaoli W. (2005). Effects of melatonin in age-related macular degeneration. Ann N Y Acad Sci. Dec;1057:384-92.
  10. Mehrzadi S, Kemati K, Reiter RJ, Hosseinzadeh A. (2020). Mitochondrial dysfunction in age-related macular degeneration: melatonin as a potential treatment. Expert Opin Ther Targets. Apr;24(4):359-378.
  11. Bonmati-Carrion MA, Arguelles-Prieto R, Martinez-Madrid MJ, Reiter R, Hardeland R, et al. (2014). Protecting the melatonin rhythm through circadian healthy light exposure. In J Mol Sci. Dec 17;15(12):23448-500.
  12. Pack, W., Hill, D.D., Wong, K.Y., (2015). Melatonin modulates M4-type ganglion-cell photoreceptors. Neuroscience, Sep 10;303:178-88.
  13. This is discussed in detail, along with other underlying factors and causes including natural treatment strategies, in my book Natural Brain Support: Your Guide to Preventing and Treating Alzheimer’s, Dementia and Other Related Diseases Naturally.
  14. Wang YY, Zheng W, Ng CH, Ungvari GS, Wei W, et al. (2017). Meta-analysis of randomized, double-blind, placebo-controlled trials of melatonin in Alzheimer’s disease. Int J Geriatr Psychiatry. Jan;32(1):50-57.
  15. Shukla M, Govitrapong P, Boontem P, Reiter RJ, Satayavivad J. (2017). Mechanisms of Melatonin in Alleviating Alzheimer’s Disease. Curr Neuropharmacol. 2017;15(7):1010-1031.
  16. Lin L, Huang QX, Yang SS, Chu J, Wang JZ, et al. (2013). Melatonin in Alzheimer’s disease. Int J Mol Sci. Jul 12;14(7):14575-93.
  17. Sulkaya S, Muggalla P, Sulkava R, Ollila HM, Peuralinna T, et al. (2018). Melatonin receptor type 1A gene linked to Alzheimer’s disease in old age. Sleep. Jul;41(7):zsy103.