• Scott Sohn, MS, RDN, LD

Melatonin: The Dark Hormone

Updated: Jul 16, 2019

The pineal gland, also called the pineal body, or Epiphysis Cerebri, is a small endocrine gland in the vertebrate brain. It produces the serotonin derivative melatonin, a hormone that affects the modulation of wake/sleep patterns and seasonal functions. The pineal gland is included among a group of specialized neuroendocrine brain structures called the circumventricular organs.1

The pineal gland has been referred to as the third eye, which came about for many reasons including its location in the center of the brain, and its sensitivity to light. The pineal gland has an interesting history from pharaonic Egypt. During that time, it was equated with the eye of Horus through various religious traditions, and was considered the seat of the soul, the third eye.1In certain dharmic spiritual traditions the third eye refers to the Ajna (or brow) chakra. The third eye refers to the gate that leads to inner realms and spaces of higher consciousness. People who are said to have the capacity to utilize their third eyes are sometimes known as seers.

Of all the endocrine organs, the pineal gland was the last to be discovered and remains the least understood. While researchers are still learning about the full purpose of the pineal gland, they believe its main function is to produce melatonin.The pineal gland produces the hormone melatonin and the substance N, N dimethyltryptamine which is known as an endogenous hallucinogen present in the brains of mammals. Recently, some have suggested that N, N-dimethyltryptamine is secreted by the pineal gland at birth, during dreaming, and at near death to produce out of body experiences.2

Melatonin maintains circadian rhythm and regulates reproductive hormones.The hormone melatonin is secreted in response to low light conditions which causes the onset of sleep. This sleep-wake cycle is called the circadian rhythm, which is a twenty-four-hour biological cycle. Light and darkness dictate the circadian rhythm. Light conditions decrease melatonin release from the pineal gland while darkness increases its release. Release of melatonin hormone by the pineal gland peaks during the nighttime, following the circadian rhythm of the body.

Melatonin is significant for its effects on our mood, immune function, circadian rhythms, and the quality and quantity of our sleep. Melatonin is known as an anti-aging and anti-stress agent because it both suppresses cortisol and is a powerful antioxidant.1

In the central nervous system melatonin plays an immunity and antioxidant role, and is also linked to neuronal development, growth, and neuronal circuit formation. Melatonin also exhibits a neuroprotective effect by acting on neural receptors to regulate levels of neurotrophic peptides which are crucial in the central nervous system for neuronal health.1Melatonin exerts its antioxidant property by increasing activity of antioxidant enzymes and increasing glutathione content. It acts via certain receptors to increase synthesis of antioxidant enzymes like glutathione peroxidase, glutathione reductase and superoxide dismutase.1Melatonin also acts as a free radical scavenger and protects against free radical-induced damage at the level of lipid membranes. Therefore, it has anti-inflammatory effects at the level of the central nervous system (CNS), by affecting the secondary injury pathway.1 Additionally, melatonin helps to preserve healthy cells while inducing cell death in cancer cells. Melatonin is observed to increase the activity of SIRT1 (sirtuin) in healthy cells, which provides a protective action. In cancer cells however, the opposite is seen, with melatonin exhibiting oncotic properties.1

Mitochondrial dysfunction and inflammation are considered primary events in the onset of neurodegenerative development. Inflammation has been seen to be a component in the pathophysiology of neurodegenerative diseases and associated depression. Neuro-inflammation is consistent across ageing, dementia, diabetes, hypertension and depression. Low-grade inflammation leads to micro vascular irregularities, less blood perfusion, loss of oligodendrocytes and increased risk of stroke.1

Neuro-inflammation is also linked with increased risk of dementia. Aging is a major factor for development of neurodegenerative diseases and is also intricately linked with inflammation. Systemic inflammatory factors increase in the body with the process of ageing and lead to chronic activation of microglia and parenchymal macrophages in the CNS, with increased number of astrocytes. This chronic pro-inflammatory state has been positively correlated with the development of neuropsychiatric disorders and neurodegenerative diseases.3

Melatonin supplementation has been shown to promote positive cognitive effects related to neurodegenerative diseases such as Multiple Sclerosis, ALS, Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Evidence shows that melatonin acts as a mitochondrial protector and helps prevent neurodegenerative diseases. The antioxidant, anti-inflammatory and neuroprotective effects of melatonin seem to aid in improving prognosis of neurodegenerative diseases and neuro-inflammatory states like traumatic brain injury.1

The many benefits and possible therapeutic applications of melatonin supplementation are very promising. Further research continues and melatonin is being combined with other molecules such as curcumin and lipoic acid to produce multi-target hybrids which act synergistically against neurodegenerative diseases.1

Most people are familiar with melatonin supplementation solely for its ability to promote and maintain sleep cycles. Melatonin is shown to shorten the time it takes to fall asleep and may improve sleep quality. Those who travel between time zones and experience “jet-lag” may benefit form melatonin supplementation to help them adjust to altered sleep patterns. Melatonin supplementation has been shown to be effective in treating the following conditions.

Evidenced based research for specific conditions include:

1. Circadian rhythm sleep disorders in the blind

2. Delayed sleep-wake phase sleep disorder

3. Insomnia

4. Jet Lag

5. Shift-work disorder

A majority of melatonin supplements are synthetically produced but chemically identical to the melatonin produced in the body (endogenous).4 Supplement manufacturers are required to list the source of the melatonin in supplements if not synthetically produced. While most melatonin supplements are man-made, there are some that are extracted from the glands of animals and are therefore not considered vegetarian.4

The amount of melatonin in products ranges from 0.3 milligrams to 10 milligrams per dose with suggested daily dosages covering a wide range as well. Melatonin comes in many forms and strengths including liquids, lozenges, tablets, capsules, softgels and time-released versions. Standard melatonin formulas work quickly, within 30 to 60 minutes, while time released versions may help extend sleep time.4

Sometimes additional ingredients are added to melatonin to increase its effectiveness in promoting sleep. Valerian is added for its calming effect while vitamin B6 is added due to its role in the synthesis of serotonin, a precursor to melatonin. The amino acid theanine is also added to some melatonin supplements for its presumed ability to reduce stress and increase mental alertness.

For those wanting to try melatonin for the first time, it is suggested to start at a very low dose of 1mg or less to see if it helps.

Uses and Dosage:

· For trouble falling asleep: 0.3 to 5 mg at bedtime.

· For insomnia: Primary insomnia 2 to 3 mg at bedtime. Secondary insomnia 2 to 12 mg.

· For sleep disorders in blind people: 0.5 to 5 mg at bedtime.

· For jet-lag: 0.5 to 8 mg at bedtime.

· For reducing anxiety before surgery: 3 to 10 mg 60-90 minutes prior.

· For sleeping problems in people with sleep-wake cycle disturbance. 2 to 12 mg bedtime.

· For insomnia in children chronic sleep onset insomnia: 5 mg at 6 PM daily.

· For insomnia in children with developmental disorders: 5 mg at 8 PM daily.

· For prevention of cluster headache: 10 mg before bedtime daily.

· Adjunct in cancer chemotherapy: 10 to 50 mg daily.

· For Irritable bowel syndrome: 3 mg at bedtime.

· For insomnia associated with the use of beta blockers: 2.5 mg one hour prior to bed.

· For delayed weekend sleep pattern: 6 mg five hours before desired Sunday bedtime.4,6

Does melatonin supplementation interfere with the body’s natural melatonin production?

Supplementing with small to moderate doses of melatonin does not appear to decrease the body’s own production of melatonin.4 Exposure to light at night, benzodiazepine drugs and caffeine have all been shown to decrease endogenous production of melatonin.4

Adverse effects:

· Drowsiness

· Headache

· Dizziness

· Nausea

The so called “hangover” effect does not appear to be shown after supplementing with regular-release products. Conversely, higher-dose, time-released products may cause next-day drowsiness as melatonin remains longer in the system.

Melatonin with prescription sedatives and sleep medications:

The current evidence on the effectiveness of taking melatonin in conjunction with sedatives or sleep medications is mixed. One study reported a number of participants using benzodiazepine medications to treat insomnia were able to discontinue those medications after six weeks of melatonin supplementation. Still, other study results have not revealed conclusive evidence that show adding melatonin to benzodiazepines has a positive outcome on sleep.4

*Always consult your physician before using melatonin in conjunction with prescription medications.

Possible Drug interactions:

  • Anticoagulants and anti-platelet drugs, herbs and supplements. These types of herbs, drugs, and supplements reduce blood clotting. Combining with melatonin may increase bleeding.

  • Anticonvulsants.

  • Blood pressure drugs. Melatonin might worsen blood pressure in those taking blood pressure medication.

  • CNS depressants. Melatonin may cause additive sedative effects.

  • Diabetes medications. Melatonin may affect sugar levels.

  • Contraceptive drugs. May cause increased melatonin effects. Cytochrome P450 1A2 (CYP1A2) and cytochrome P450 2C19 (CPY2C19) substrates. Use melatonin cautiously if you take drugs such as diazepam (Valium) and others that are affected by these enzymes.

  • Fluvoxamine (Luvox). This selective serotonin reuptake inhibitor can increase melatonin levels, causing unwanted excessive drowsiness.

  • Immunosuppressants. Melatonin can stimulate immune function and interfere with immunosuppressive therapy.

  • Seizure threshold lowering drugs. Taking melatonin with these drugs might increase the risk of seizures.5

*Melatonin is generally considered safe for most adults when taken orally, injected or applied topically on a short-term basis.

*Melatonin is possibly considered safe when used on a long-term basis.6

If you are experiencing sleep onset difficulties or any of the sleep conditions listed above, melatonin supplementation may help. Some people use melatonin as a nightly supplement to aid with sleep, and to simultaneously act as an antioxidant and neuroprotectant. Ongoing research studies continue to examine melatonin for its many metabolic benefits as well as its potential in the prevention and treatment of neuro-degenerative diseases.

  • Consult your doctor before using melatonin if you take any of the prescription medications listed above or have a neurological condition.

  • The safety of melatonin in young children, pregnant or nursing women, or people with severe liver or kidney disease has not been established.

1. Beriwal, Nitya et al. (2019). Role of immune-pineal axis in neurodegenerative diseases, unraveling novel hybrid dark hormone therapies. j. heliyon. 5,1, 1190.

2. Nichols DE. (2018).N, N-dimethyltryptamine and the pineal gland: Separating fact from myth. J Psychopharmacology. 32(1), 30-36.

3. W. ChenW, X.I.A. Zhang, W.-J. Huang. (2016). Role of neuroinflammation in neurodegenerative diseases. Mol. Med. Rep. 13 (4), 3391–3396.

4.Consumer Labs. (2019, March 19). Melatonin Supplement Review. Retrieved From http://www.consumerlab.com

5. Bauer, B. (2017, October 10). Is melatonin a helpful sleep aid?. Retrieved Fromhttp://www.mayoclinic.org

6. WebMD. (2019, July 12). Melatonin. Retrieved From http://www.webmd.com

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