Melatonin is a hormone that your brain produces in response to darkness. It helps with the timing of your circadian rhythms (24-hour internal clock) and with sleep. Being exposed to light at night can block melatonin production.
Research suggests that melatonin plays other important roles in the body beyond sleep. However, these effects are not fully understood.
Melatonin dietary supplement can be made from animals or microorganisms, but most often they’re made synthetically. The information below is about melatonin dietary supplements.
In most animals, melatonin is mainly synthesized and secreted at night (converted from tryptophan). It is also synthesized in many tissues and cells, including retina, bone marrow cells, platelets, gastrointestinal tract, skin or lymphocytes
Melatonin receptors are scattered throughout the body and seem to be a multi-purpose physiological signal that participates in the control of many physiological processes, thereby affecting sleep, reproduction, molting, immune response, energy balance, and behavior.
In addition, it also has direct and indirect antioxidant properties. There is strong evidence that this compound can offset the harmful effects of reactive oxygen and nitrogen in different systems.
When is melatonin taken (dose)?
If you want to try melatonin, it is best to start with a low dose.
For example, take 0.5 mg/mg (500 mcg) or 1 mg 30 minutes before going to bed.
If this dose does not help you fall asleep, try increasing it to 3 to 5 mg.
But taking more melatonin may not help you fall asleep faster. The goal is to find the lowest dose that makes you fall asleep.
What are the empirical effects (benefits) of melatonin?
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Melatonin improves primary sleep disorders
Primary Sleep Disorders is a type of insomnia that is not caused by medical, mental or environmental reasons. It is based on the diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).
The main symptoms of primary insomnia are difficulty in starting or maintaining sleep, or suffering from non-restorative sleep that lasts for at least 1 month.
The second criterion is that sleep disorders (or related daytime fatigue) cause significant pain or damage in social, professional, or other important functional areas.
The third criterion is sleep disorders that do not completely occur in narcolepsy, breathing-related sleep disorders, circadian rhythm sleep disorders, or abnormal sleep
The fourth criterion is that it does not completely occur in the process of another mental disorder (such as major depressive disorder, generalized anxiety disorder, delirium).
Finally, the fifth criterion is not caused by direct physiological effects of substances (such as drug abuse, drug treatment) or general medical conditions.
＊Conclusion: For primary sleep disorders, oral melatonin can improve the sleep state of patients, but it is limited by the small number of samples, and more large-scale experiments are needed to prove it
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Melatonin improves secondary sleep disorders
In addition to the primary factors mentioned above, chronic insomnia also has secondary sleep disorders, which are usually caused by medical conditions, neurological, environmental, drug or psychiatric reasons.
Medical causes include pain, thyroid disease, acid reflux, coronary artery disease, lung disease (chronic obstructive pulmonary disease, asthma, sleep apnea, central alveolar hypoxia syndrome), chronic renal insufficiency, eating disorders, and thyroid dysfunction , Fibromyalgia, menstrual-related sleep disorders, and pregnancy
Neurological causes include headache, Parkinson’s disease, and sleep-related movement disorders (nocturnal muscle twitches, RLS)
Environmental factors include excessive noise, harmful odors, strong light, or extreme ambient temperature. Drugs and mental factors include: alcoholism, anxiety disorders, mood disorders, panic disorders and other mental disorders
＊Conclusion: For secondary sleep disorders, oral melatonin has a positive effect on improving symptoms, but it is limited by the small number of samples and potential biases, and more accurate trials are needed to support it.
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Melatonin is beneficial for blood pressure regulation
Blood pressure is defined as the pressure of blood circulation on the walls of blood vessels, and the human body can adjust blood pressure as needed, so changes in blood pressure readings are normal. However, if the blood pressure is too high for too long, it will damage the blood vessels over time, increasing the risk of various health problems.
Long-term high blood pressure will increase the possibility of cardiovascular disease and cause organ damage. The possible long-term effects include: poor blood circulation in the legs, heart failure, stroke, kidney failure, etc.
＊Conclusion: Oral melatonin can bring positive help to blood pressure regulation, but the relevant results still need more accurate clinical trials to corroborate
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Melatonin is good for fibromyalgia
Fibromyalgia syndrome (Fibromyalgia) is a chronic disease (estimated prevalence of 0.5% to 5.8%). It is characterized by general pain, fatigue, sleep disturbance, cognitive impairment, and anxiety. The etiology is unknown and can be associated with hypothyroidism and hypothyroidism. Chronic autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus coexist
The potential pathophysiological factors include biological and genetic influences, environmental triggers, neuroendocrine and autonomic nervous system dysfunction.
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Melatonin lowers blood lipids
Dyslipidemia (dyslipidemia) is a lipid metabolism disorder that causes abnormal lipid content in the blood. It is a major risk factor for cardiovascular disease, stroke and type 2 diabetes
Studies have shown that for every 10 mg/dL increase in total cholesterol, total mortality and cardiovascular mortality increase by 5% and 9% respectively
＊Conclusion: Oral melatonin has a positive effect on improving blood lipid levels, but it is limited by the small number of samples and sample heterogeneity, and more studies are needed for further verification
- Melatonin is good for blood sugar control
Type 2 diabetes mellitus is a disease that affects more than 400 million people worldwide. By 2040, there will be more than 640 million people with diabetes worldwide
Common symptoms of high blood sugar include polyuria, polydipsia, weight loss, sometimes accompanied by polyphagia and blurred vision.
Long-term complications include: retinopathy, kidney disease, foot ulcers, amputations, Charcot joints, and autonomic neuropathy that cause gastrointestinal, genitourinary system, cardiovascular symptoms, and sexual dysfunction.
＊Conclusion: Melatonin may have a positive effect on blood sugar control, but it is limited by publication bias, and more long-term trials are needed to support it
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Melatonin assists cancer treatment
Cancer is a disease in which the uncontrolled proliferation of cells in the organism leads to the invasive decline of normal cells or tissues
Current cancer treatment is based on radiotherapy, chemotherapy and surgery. Radiotherapy and chemotherapy inhibit the proliferation of cancer cells by destroying DNA. However, DNA damage can interfere with normal cells throughout the body, with many side effects
＊Conclusion: Adjuvant melatonin therapy can help improve the tumor remission rate and overall survival rate of cancer patients, while reducing the incidence of chemotherapy side effects. However, due to possible publication bias, more studies are needed to confirm its clinical benefits
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Melatonin improves jet lag syndrome (adjusts jet lag)
Jet lag syndrome (Jet Lag), also known as circadian rhythm disorder, is a sleep disorder that is caused by a mismatch between the body’s natural circadian rhythm and the external environment due to rapid travel through multiple time zones.
Jet lag syndrome is characterized by sleep disturbances, daytime fatigue, decreased performance, gastrointestinal problems, and general malaise
This common problem affects all age groups, but the impact on the elderly may be more pronounced. This is because the elderly take longer to adjust than the young.
＊Conclusion: Oral melatonin can improve the circadian clock imbalance caused by jet lag and help fall asleep
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Melatonin improves mood disorders
Emotional disorder is a common mental illness. It is estimated that 8% to 20% of the world’s population are affected. Depression is the most common. The main symptoms are endless sadness, loss of interest in things, and negative beliefs about oneself. , Suicidal thoughts and changes in sleep, appetite, and sexual desire patterns
Although medication and other adjuvant therapies can help the condition, 30%-40% of depression patients still resist treatment.
＊Conclusion: Oral melatonin cannot significantly improve the symptoms of depression. As the current results are still inconsistent, more studies are needed to confirm
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Melatonin prevents primary headaches
Headache is one of the most common neurological diseases, with an incidence rate of 48.9% in the general population
Primary Headache Disorders refers to headaches that occur independently and are not caused by other diseases. It accounts for almost 98% of all headaches. It can be divided into four categories: migraine, tension-type headache, cluster headache, and trigeminal nerve autonomy Headache and other primary headaches
＊Conclusion: Due to the insufficient number of studies and poor methodological quality, the existing evidence is still insufficient to support the use of melatonin to prevent primary headaches
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Melatonin relieves pain
Pain is defined as a multi-faceted entity, including nociception, central nervous system afferent, regulation, emotional response, endogenous analgesia, behavior regulation, and changes in social roles.
With the advancement of medical treatment, chronic pain is still beyond the reach of health experts, because it is an uncontrollable disease despite the well-established treatment methods.
Part of the reason is that the pathogenesis of pain includes three aspects: pain (local conditions), emotions (fear and depression), and behavioral factors (catastrophe, vigilance, and physical awareness).
＊Conclusion: Exogenous melatonin can bring positive help to anti-pain, but it is limited by the heterogeneity of the included research, and more research is needed to confirm
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Melatonin benefits Alzheimer’s disease
Alzheimer’s disease is the most common cause of dementia in the elderly. The typical feature is the gradual decline of memory, language and intelligence
The most common sleep disturbances in patients are: excessive waking (23%), waking up in the morning (11%), extreme daytime sleepiness (10%), and nap for more than 1 hour during the day (14%)
＊Conclusion: For patients with Alzheimer’s disease, the use of melatonin can help improve sleep
Are there any side effects of melatonin?
For most adults, short-term use of melatonin in small doses is still safe, but there are no rigorous experiments to prove its safety for long-term use.
Safety precautions (use taboo at 18:00)
- If you consider additional melatonin supplementation due to sleep disorders, it is best to consult a doctor first to confirm the relevant hormone levels and confirm the cause of the sleep problem
- May produce more lucid dreams (lucid dream), that is, you can realize that you are dreaming when dreaming
- It is not recommended for pregnant women, children, breastfeeding mothers, and people with liver and kidney dysfunction, because the safety is still unknown
- Do not use it in patients with low blood pressure or taking antihypertensive drugs (Melatonin has the effect of lowering blood pressure and may also interfere with the effect of drugs)
- Do not drive or operate machinery after taking (drowsiness and decreased concentration will occur)
- Animal studies found that (using subcutaneous injections) may affect the function of testicles and ovaries, but more studies are still needed to confirm
- Do not use together with anticoagulants, immunosuppressants, non-steroidal anti-inflammatory drugs NSAIDs, radiotherapy and chemotherapy drugs (may interfere with the effect of drugs, please confirm with your doctor before use)
- Some claims that taking too much melatonin will prevent the body from naturally producing melatonin, but short-term studies have shown no such effect. Note 11
- Do not use with contraceptives (because contraceptives may increase the level of melatonin, if taken additionally, it will exceed the normal safe amount)
- Do not use in combination with sleeping and sedative drugs (central nervous system depressants), which may cause excessive sleepiness. Related drug names are: clonazepam (clonazepam), lorazepam (lorazepam), phenobarbital (phenobarbital) ), zolpidem (zuo Peimian), diazepam (stability)
- Do not use it in combination with caffeine. Caffeine may reduce the level of melatonin in the body. If used together, it will reduce the effect of supplements.
- Do not use together with the antidepressant MELATONIN (fluvoxamine), which may increase the absorption of melatonin, thereby increasing the probability of adverse reactions or side effects
- Do not use in combination with hypoglycemic drugs or insulin, which may affect the effectiveness of glucose control drugs. Related drug names are: glimepiride, glyburide, pioglitazone, rosiglitazone Ketones), chlorpropamide (chlorpropamide), glipizide (glipizide), tolbutamide (methionine)
- Do not use in combination with immunosuppressive agents, which may reduce the efficacy of the drug (because melatonin may enhance the immune system). The related drug names are: azathioprine (azathioprine), basiliximab (baliximab)), cyclosporine, daclizumab, muromonab-CD3, mycophenolate, tacrolimus, sirolimus, rapamycin , Prednisone (prednisone), corticosteroids (corticosteroids)
- Do not use in combination with drugs with anticoagulant effects, which may increase the chance of bruising and bleeding (because melatonin may slow blood clotting). The related drug names are: aspirin (aspirin), clopidogrel (clopidogrel) , Diclofenac (diclofenac), ibuprofen (ibuprofen), naproxen (naproxen), dalteparin (dalteparin sodium), enoxaparin (enoxaparin), heparin (heparin), warfarin (warfarin)
- Do not use in combination with the blood pressure lowering drug Nifedipine GITS, which may reduce the efficacy of the drug
- Do not use it in combination with the drug Verapamil, which is used to lower blood pressure and prevent angina pectoris, as it may reduce the effectiveness of melatonin (because the process of metabolizing this drug will consume melatonin)
- Do not use it in combination with central nervous system drugs Flumazenil, which may reduce the effect of melatonin supplements.