Dr MB’s Melatonin
The Sleep Hormone
What Is Melatonin?
Melatonin (N-acetyl-5-methoxytryptamine) is a hormone secreted by the pineal gland in the brain, which is located just above the “middle brain” and is about the size of a pea.
This hormone is responsible for setting your “sleep-wake cycle” and for maintaining your body’s circadian rhythm, so long as you take the proper melatonin dosage. Its synthesis and release are stimulated by darkness and suppressed by light.
Your circadian rhythm is the fancier term for your own person internal clock, which runs on a 24-hour schedule, just like the day. This internal clock plays a critical role in when you fall asleep and wake up, so regulating it is critical for dealing with sleep disorders.
When it’s dark, your body produces more melatonin, but when it’s light, the production of melatonin goes down. This is why people who are blind or work night hours can have problems with maintaining normal levels.
For anyone, a lack of light exposure during the day, or exposure to bright lights in the evening, can disrupt the body’s normal melatonin cycles.
Melatonin is also crucial to female reproductive health as it plays a role in controlling the timing and release of female reproductive hormones. It helps decide when a woman starts to menstruate, the frequency and length of menstrual cycles, as well as when a woman stops menstruating completely (menopause).
Researchers believe that melatonin decreases as we age and that young children have the highest levels (particularly at night, which is why they typically sleep longer and more deeply than adults). If this is true, then it can help explain why older people don’t tend to sleep as well as they did when they were younger.
How It Works
When you’re exposed to light, it stimulates a nerve pathway from the retina in the eye to an area in the brain called the hypothalamus. This is where the suprachiasmatic nucleus (SCN) is located, and the SCN initiates the turning on of the pineal gland.
Once the SCN turns on the pineal gland, it starts making melatonin, which is then released into your bloodstream.
The precursor to melatonin is serotonin, a neurotransmitter that’s derived from the amino acid tryptophan. A naturally occurring chemical called acetylserotonin acts as the intermediary.
Serotonin produces acetylserotonin, which is then converted into melatonin.
Besides its role as a precursor in the synthesis of melatonin, acetylserotonin is also known to have antidepressant, anti-aging and cognitive-enhancing benefits.
Many of the health benefits that are thought to be due to increasing serotonin levels may actually come from serotonin’s ability to make melatonin production possible.
In most adults, the body starts producing melatonin around 9 p.m. Levels then increase sharply, and you begin to feel more sleepy.
If your body is running as it should, your level remains elevated while you sleep, for a total of approximately 12 hours. It then drops, and by around 9 a.m., the level is back to a barely detectable level, where it remains during the day.
What is melatonin used for when taken as a supplement? By far, its best known usage is as a natural sleep aid.
But did you know that it also serves many other functions too, such as supporting your immune system, cardiovascular function and reproductive health?
Recent studies indicate that some of the many uses/functions of melatonin include:
- Fighting free radicals and having antioxidant actions
- Facilitating bone formation and protection
- Assisting in reproduction
- Supporting detoxification
- Regulating body mass
- Providing gastrointestinal protection
- Protecting against psychiatric disorders, mood disorders and cardiovascular diseases
- and more
14 top Melatonin benefits and uses:
1. Natural Sleep Aid
Research suggests that supplementing with melatonin may help people with disrupted circadian rhythms, such as people who work the night shift and people who have jet lag. Supplementation may also help individuals sleep better who have chronically low levels, like people with schizophrenia, who have poor sleep quality.
One randomised, double-blind trial found that two milligrams of melatonin prolonged release (PR) given one to two hours before bedtime was associated with significant improvements compared to a placebo in sleep quality and length, morning alertness, and health-related quality of life. The study also found that whether the melatonin dosage (two milligrams PR) was short- or long-term, there was no dependence, tolerance, rebound insomnia or withdrawal symptoms.
Studies have uncovered evidence that melatonin is effective in advancing sleep-wake rhythms in people with delayed sleep phase disorder. Delayed sleep phases are experienced by those who struggle with waking up later in the morning than is considered normal/socially acceptable.
Taking melatonin can help people with this sleep problem fall asleep a bit sooner, although it can take some trial and error to determine the best timing and dose.
Recent research indicates that to be most effective in treating delayed sleep, it’s best to take small doses four to eight hours before desired sleep time. In some cases, it may make only a small difference in terms of time to fall asleep, such as by helping people drift off about 10 minutes earlier.
2. Potentially Helps Treat Cancer
Several studies suggest that low melatonin levels may be associated with risk for certain types of cancers. A 2017 study published in Oncotarget states, “Melatonin could be an excellent candidate for the prevention and treatment of several cancers, such as breast cancer, prostate cancer, gastric cancer and colorectal cancer.”
To determine this hormone’s effectiveness at stopping tumour growth, in 2014 one group of researchers evaluated its actions on the growth of breast tumours in vitro (using human cancer cells) and in vivo (using mice). The researchers found that melatonin may inhibit tumour growth and cell production, as well as block the formation of new blood vessels in estrogen receptor-negative breast cancer models.
Another study looked at women who were taking the chemotherapy drug tamoxifen for breast cancer but not seeing any improvement. With the addition of melatonin to their treatment regimens, researchers found that tumours “modestly” shrank in more than 28 percent of the women.
Studies also show that men with prostate cancer have lower melatonin levels than men without the disease.
One study published in Oncology Reports aimed to verify whether melatonin might modulate the growth of androgen-dependent prostate cancer cells. The results demonstrated that it can significantly inhibit the proliferation of prostate cancer cells.
Combined, these studies and others show melatonin’s great promise as a potential natural treatment for cancer. However, if you have cancer, you should always speak with your doctor before taking any supplements/over-the-counter treatments.
3. Decreases Negative Menopause Symptoms
Melatonin supplements have been shown to improve sleep problems experienced during menopause. In a study of perimenopausal and menopausal women ages 42 to 62, within six months of daily supplementation, most of the women reported a general improvement of mood and a significant mitigation of depression.
The findings of this study appear to demonstrate that supplementation among perimenopausal and menopausal women can lead to recovery of pituitary and thyroid functions that is more in the direction of a youthful pattern of regulation. This is great news because it shows that this hormone can help to decrease common negative perimenopause symptoms and menopause symptoms, like sleeping problems.
4. Heart Disease Helper
Multiple studies suggest that melatonin has heart-protective properties. Specifically, research shows that when it comes to cardiovascular health, it has certain anti-inflammatory and antioxidant effects.
It also may help lower blood pressure and cholesterol. Its cardioprotective properties seem to come from its “direct free radical scavenger activity,” according to studies.
5. Fibromyalgia and Chronic Pain Relief
Fibromyalgia symptoms include long-term and widespread pain in muscles and connective tissues, without any specific cause.
A randomised, placebo-controlled study of 101 patients with fibromyalgia syndrome evaluated melatonin’s effectiveness at reducing symptoms. The study found that patients experienced a significant reduction in their fibromyalgia symptoms when they supplemented either alone or in conjunction with the antidepressant fluoxetine (Prozac).
The group who took only melatonin was given a daily dosage of five milligrams while the other group took three milligrams and 2o milligrams of the antidepressant.
Other studies suggest that melatonin might be able to help with other chronic painful conditions, like migraine headaches. A 2019 systematic review found that in a number of studies, melatonin reduced headache frequency (attack frequency or number of headache days), duration and intensity significantly.
Headache frequency decreased by 33 percent to 83 percent, averaging 51 percent. The reduction of headache duration was 32 percent to 56 percent (average 46 percent), and headache intensity was 33 percent to 78 percent (average 53 percent) among adults involved in the studies that were reviewed.
6. Immune System Strengthener
Research shows that melatonin has strong antioxidant effects and may help strengthen the immune system. A 2013 scientific review called melatonin an “immune buffer” because it appears to act as a stimulant in an immunosuppressive condition — plus it also behaves as an anti-inflammatory compound when there’s an intensified immune response, like in the case of acute inflammation.
7. Eases Jet Lag
Supplementing with melatonin may be able to help “reset” your sleep and wake cycle when you experience dreaded jet lag.
A scientific review of a large number of trials and studies all involving melatonin and treatment of jet lag found evidence that melatonin is “remarkably effective in preventing or reducing jet-lag, and occasional short-term use appears to be safe.” The researchers found that in nine out of 10 trials, when it was taken close to the target bedtime at the destination (10 p.m. to 12 a.m.), there was a decrease in jet lag from crossing five or more time zones.
The researchers also observed that daily doses between 0.5 and five milligrams worked similarly well, but subjects did fall asleep faster and sleep better after taking five milligrams compared to 0.5 milligrams.
When a dosage above five milligrams was given, it did not produce any better results. Another key conclusion is that the timing is key because if it’s taken too early then it can delay adaptation to the new time zone.
The incidence of other side effects from melatonin dosage was found to be low.
8. Better Outcomes for Autism in Children
Research has shown that melatonin can help children with developmental issues like autism.
A 2011 scientific review published in Developmental Medicine and Child Neurology evaluated 35 studies that had melatonin-related findings involving autism spectrum disorders, including autistic disorder, Asperger’s syndrome, Rett syndrome and other common developmental disorders. After reviewing the numerous studies, researchers concluded that melatonin supplementation in autism spectrum disorders is linked to better sleep parameters, improved daytime behaviour and minimal side effects.
9. May Ease Tinnitus
Research suggests that melatonin may serve as a natural tinnitus treatment.
Tinnitus is a condition that causes noise or ringing in the ears. The antioxidant properties of melatonin may contribute to its ability to alleviate tinnitus.
Researchers at the Ohio State University Eye and Ear Institute conducted a study involving 61 participants. After taking three milligrams of melatonin nightly for 30 days, the participants experienced a significantly greater decrease in tinnitus symptoms.
Supplementation also helped improve the quality of sleep in patients with chronic tinnitus.
10. Can Help Relieve Bladder Dysfunction
Melatonin receptors are found in the bladder and the prostate. It works to prevent elevations in levels of malondialdehyde, which is a marker for oxidative stress.
Through the reduction of oxidative stress, melatonin helps combat age-induced bladder dysfunction. It also limits bladder contractions and induces relaxation, helping relieve issues like overactive bladder.
An article review published in Current Urology found that, although the exact mechanisms of action are not yet fully understood, there is a strong body of evidence suggesting that a melatonin imbalance can have a detrimental effect on bladder dysfunction.
A 2012 study suggests that nightly production of melatonin helps improve sleep and reduce habitual nightly urination. Supplementation also seems to increase bladder capacity and decrease urine volume due to its effects on the central nervous system.
11. Helps Relieve Stress
Melatonin levels change when you experience stress. Stress decreases concentrations at night and increases production during the day, which is due to the increase of cortisol, the stress hormone.
Melatonin can help to relieve stress by controlling the level of stimulation experienced by the body.
If you feel anxious, melatonin helps ease anxiety symptoms like daytime fatigue, drowsiness, insomnia and restlessness. It also promotes a calm mood and supports brain function.
12. Supports Production of Human Growth Hormone
Supplementing with melatonin has been shown in some studies to help increase human growth hormone levels in healthy men under 40, which can have benefits such as supporting growth of muscle mass and a healthy metabolism.
There’s also evidence indicating that at low doses it can increase oxytocin and vasopressin levels, which may impact moods, blood pressure levels and other functions.
13. Helps Prevent Mood Disturbances
As pointed out by a 2017 study, “Circadian rhythm alterations resulting in disturbed sleep and disturbed melatonin secretion are flagship features of depression.” Mood disturbances, including seasonal depression, seem to be impacted by exposure to light and sleep cycles.
There’s evidence suggesting that melatonin may help decrease depression symptoms by regulating serotonergic neurotransmission.
14. May Help Protect the Brain
Although there’s more to learn about the topic, there’s emerging evidence showing that melatonin may help protect against neurodegenerative diseases, such as Alzheimer’s disease. It seems to improve neuronal survival and may be able to help protect the cholinergic system against oxidative stress and inflammation.
Recent clinical trials indicate that supplementation can improve sleep and slow down the progression of cognitive impairment in Alzheimer’s patients.
For sleep troubles, you should know that the right dose should help you sleep well with no daytime tiredness or irritability, so if you’re always tired, it can be a great option to reverse that trend.
It’s always a good idea to start off with a very low dose of melatonin and see how you do. You can follow supplement directions on the label or consult an expert if you’re unsure about how much to take.