So even though melatonin is commonly known as a sleep aid, it has many attributes that can help restore and preserve your health. There’s growing evidence that this natural hormone fights bacteria, inhibits viral infections, improves symptoms of depression, enhances cognitive function, has cardio-protective effects, supports liver health, and may improve menopausal symptoms.

Melatonin is best known for the way it supports healthy sleep cycles. Natural melatonin production is considerably reduced when light strikes the retina of the eye. If you stay up late watching television or using smartphones, tablets, or computers, you’re interrupting your body’s own melatonin production. Melatonin helps regulate your circadian rhythms, which regulate your sleep and wake schedule. It impacts REM (rapid eye movement) and stage 4 sleep. That’s the stage of rejuvenating sleep you need to think clearly, stay focused, repair muscle tissue, relieve pain, and recharge your immune system. Stage 4 sleep is critical to good health! In our modern world, we have a lot of threats to melatonin: light pollution, aging, shift work, screen time, and late nights. Over time, it adds up. Just two hours of continuous screen time deplete melatonin levels by 22 percent. After a while, these factors take a toll. Younger people typically have about 8-10 times more naturally circulating melatonin at night than they do during the day. That makes sense because sunlight depletes melatonin levels as part of our natural circadian rhythms. But older individuals may only have twice as much natural melatonin at night compared to daytime hours.

Melatonin is present in every cell in the body and affects virtually every aspect of well-being. But melatonin levels decline with age, under stress, or with coexisting health conditions. That’s why getting a supplemental source can make an incredibly positive impact on your health. Melatonin is, in many ways, like vitamin D—a critical component of health that has been here all along but is finally becoming recognized for its incredible value.

Over the years I have spoken extensively about melatonin supplementation. It’s my conclusion, based on a review of current medical/nutritional literature, personal experience, and clinical experience that standard or “quick release” forms of melatonin are problematic in terms of dosing and occurrence of side effects.  I have found that some people can use sublingual, rapid-release melatonin on a regular basis and experience 5-7 hours of restful sleep, however, most people that I have spoken with report that it may work well for a few days or weeks and then stops working or causes disrupted sleep.  Many people experience initial sleepiness only to wake up in the middle of the night and not be able to return to sleep. This is because melatonin is quickly metabolized by the body, so some supplemental forms can be completely cycled through in as little as two hours. To get the most benefit from melatonin and avoid any side effects I recommend using a sustained-release form (5-10 mg) that slowly administers itself into your bloodstream over time as it breaks down in the digestive tract. This is the same form that is used in clinical research because it helps reestablish circadian rhythms more efficiently and effectively.  The sustained-release form does not produce side effects and keeps you in a deeper state of sleep for a longer period of time.  It should also be noted that for most people this form of melatonin will not produce active nightmares.

Here are some of the many health benefits associated with melatonin supplementation:

Immune System

Melatonin provides a baseline of protection all the time against the usual germs, bacteria, and viruses that we are likely to encounter on a regular basis. It has a moderating effect on the immune system, keeping it strong and organized.  In Europe, researchers are using it to treat and modulate dangerous viruses, including COVID-19.

Depression

Our state of mind is directly related to circadian rhythms. Clinical work has found that by synchronizing those rhythms through treatment with melatonin, people can feel some relief from the symptoms of depression. Melatonin can help change the way the brain is structured and how it learns new habits and emotional responses. In scientific terms, this is known as neuroplasticity—the ability of the brain to change, grow and develop.

Cognition

The boost in neuroplasticity from melatonin also makes it a compelling option for individuals with cognitive and neurological disorders like Alzheimer’s disease (AD) or Parkinson’s. Melatonin can also inhibit the buildup of beta-amyloid plaque in the brain, associated with Alzheimer’s. And there is a relationship between lack of sleep and neurodegeneration. It’s not just about whether you feel groggy in the morning —your brain needs restorative sleep in order to function. It’s been estimated that 63 percent of adults with mild cognitive impairment (MCI) and about 44 percent of those with Alzheimer’s have significantly interrupted or disturbed sleep.

Cardiovascular

Cardio health, including blood pressure, lipid levels, heart muscle strength, and vascular integrity are all tied to melatonin levels. In fact, continual light is a major risk factor for heart disease because of the way it depletes melatonin. So, while it’s healthy to get outside in the summertime for plenty of exercise and fresh air, it’s equally important to reclaim your nighttime and keep lights to a minimum in the evening. We need darkness to stay healthy! Studies have found that melatonin lowers blood pressure levels, reduces LDL cholesterol, and restores the health of blood vessels, in part, by normalizing nitric oxide levels and decreasing the reactivity and oxidative stress in arteries and veins.

Liver

When it comes to liver protection, melatonin also plays an important role. In a clinical study of individuals with NAFLD, 10 mg of melatonin (5 mg, twice daily) significantly reduced triglyceride and LDL cholesterol, improved fat metabolism in the liver, and lowered inflammatory cytokine levels. Melatonin also fights cirrhosis by preventing or inhibiting liver cell death and stopping liver inflammation. Melatonin inhibits macrophage, mast cell, and leucocyte activity implicated in cases of liver fibrosis.

Menopause

In one clinical study, postmenopausal women who had experienced weight gain also had lower levels of melatonin. Since melatonin tends to help slow weight gain, researchers believe it’s because of its inhibition of appetite-stimulating digestive enzymes and acids. And, while low levels of estrogen can be a factor in weight, melatonin levels appear to be just as important. Melatonin supplementation could be an effective alternative for women who have difficulty tolerating hormone therapy. For those in perimenopause, a clinical study of women ages 45-54 found that melatonin can improve symptoms, reduce menstrual cycling, and lengthen the time between menstrual cycles. Plus, melatonin helps prevent bone loss, a common occurrence— especially for women—as they get older.

Michael Chase, MS, NTP

Nutrition Science and Dietetics