Melatonin is a naturally occurring hormone that is primarily produced by the pineal gland in the brain. It plays a central role in regulating the sleep–wake cycle and maintaining the body’s circadian rhythm.
Endogenous melatonin (melatonin produced within the body) helps synchronize internal biological rhythms with the external light–dark cycle. Its secretion increases during the evening and night, promoting sleepiness, and decreases during daylight hours, supporting wakefulness. Through this rhythmic secretion, melatonin helps the body recognize when to rest and when to be alert.
Melatonin is therefore an essential hormonal signal for sleep initiation and sleep timing, rather than a sedative itself. It supports the natural process of falling asleep and waking after adequate rest.
In addition to natural production, melatonin can also be synthesized in laboratories and is available as a dietary supplement. This form is known as exogenous melatonin and is commonly used to manage sleep-related disorders and circadian rhythm disturbances.
Function of Melatonin
Melatonin plays a key role in regulating the body’s circadian rhythm. The circadian rhythm is the natural sleep–wake cycle that follows a 24-hour pattern.
–Melatonin prepares the body for sleep. It does not directly cause sleep, but it signals the body that it is time to slow down and rest.
–The pineal gland secretes melatonin in response to darkness. Melatonin levels are highest at night and lowest during daylight hours.
–Exposure to light suppresses melatonin secretion. This is why melatonin levels fall in the morning and rise after sunset.
–The duration of melatonin secretion depends on the length of darkness. Longer nights result in prolonged melatonin release.
–During winter months, reduced daylight leads to increased melatonin secretion. This explains why people may feel sleepy earlier or experience increased sleepiness in winter.
Mechanism of Action of Melatonin
Melatonin acts as a chemical messenger that signals the body to enter a state of rest. The pineal gland releases melatonin at roughly the same time every evening, usually after sunset.
Melatonin primarily acts on the hypothalamus. It signals the hypothalamus to reduce daily physiological activity.
In response, the hypothalamus slows down functions such as:
–Body temperature
–Blood pressure
–Emotional alertness
These changes help prepare the body for sleep.
Melatonin also acts on the retina of the eyes. It reduces retinal sensitivity to light, promoting relaxation and reduced alertness.
With morning light exposure, retinal activity increases. This suppresses melatonin secretion and promotes wakefulness.
Ayurveda Viewpoint
The pineal gland which secretes the hormone melatonin is located in the brain (head) which is also the chief seat of Prana Vayu. The functions of these are directly related to those of Prana Vayu to a greater extent and also to those rendered by Sadhaka Pitta and Tarpaka Kapha and also Udana Vayu. The functions of the mentioned dosha subtypes can thus be attributed to the neuro-endocrine functions of pineal gland and those of Melatonin. The circadian rhythm is a resultant of balance and coordinated functioning of these dosha subtypes.
The detachment of manas i.e. mind from its senses (indriyas) is very much essential for the person to withdraw from the worldly objects and slip into a pleasant sleep while its indulgence with the indriyas brings about alertness.
The physiology of sleep, its benefits and harmful effects as explained in Ayurveda reflects the entire game of Melatonin.
The functions of pineal gland and melatonin represent the synchronized functional axis of Prana Vata and other Vata Subtypes. They grossly and subtly represent the functions of the entire orchestra of the endocrinal / hormonal system. The pineal gland too serves as the key link between the nervous system and hormonal regulation.
Related Reading – Ayurveda Understanding of Circadian Rhythm, Pineal Gland and Functions and Dysfunctions of Melatonin
Benefits of Melatonin
Melatonin plays a central role in maintaining the body’s internal biological rhythm. Its primary function is to regulate the sleep–wake cycle, but its influence extends to several physiological systems.
Regulation of Sleep and Circadian Rhythm
Melatonin acts as the body’s natural signal for sleep onset. It helps prepare the body for rest by synchronizing the circadian rhythm with the light–dark cycle. Adequate melatonin secretion supports restorative sleep, which is essential for overall health, including the maintenance of:
–Mental and emotional well-being
–Skin health
–Hair health
–Optimal function of internal organs
Because of this role, melatonin is often referred to as the “sleep hormone” and is commonly used as a natural aid in certain sleep disorders.
Seasonal Affective Disorder (SAD)
Seasonal affective disorder is associated with changes in daylight exposure across seasons.
–Winter-pattern SAD may be linked to increased melatonin secretion due to prolonged darkness.
–Summer-pattern SAD, which accounts for a smaller proportion of cases, may involve relatively lower melatonin levels.
The exact role of melatonin in SAD is still under investigation, and further research is needed to clarify its therapeutic significance.
Reproductive and Hormonal Balance
Melatonin contributes to the regulation of reproductive hormones and is believed to help maintain regular menstrual cycles by interacting with the hypothalamic–pituitary–gonadal axis.
Neuroprotective Effects
Melatonin exhibits neuroprotective properties. It may help protect brain cells from oxidative damage and degeneration, processes that are associated with neurodegenerative conditions such as Alzheimer’s disease and Parkinson’s disease. While experimental and observational studies are promising, definitive clinical evidence is still evolving.
Antioxidant and Cellular Protection
Melatonin is a potent antioxidant. It helps neutralize free radicals, thereby reducing cellular damage. This antioxidant action may support eye health and overall cellular integrity, though long-term effects of supplemental melatonin require further human studies.
Gastrointestinal Benefits
Melatonin has been shown to influence gastrointestinal function. It may:
–Reduce gastric acid secretion
–Decrease nitric oxide production, thereby preventing excessive relaxation of the lower esophageal sphincter
Through these mechanisms, melatonin may help alleviate symptoms of gastroesophageal reflux disease (GERD), such as heartburn and acid reflux.
Therapeutic Uses of Melatonin (Based on Evidence)
Likely Effective
–Delayed sleep phase syndrome: Helps reduce sleep-onset latency in children and young adults
–Non-24-hour sleep–wake disorder: Improves sleep patterns in blind children and adults
Possibly Effective
–Beta-blocker–induced insomnia
–Adjunctive use in certain cancers (under medical supervision)
–Reduction of postoperative confusion and agitation in children
–Controlled-release melatonin for hypertension
–Short-term management of insomnia, particularly in older adults
–Jet lag symptom relief
–Migraine prevention
–Pre-procedure anxiety and sedation reduction
–Sunburn prevention (topical use)
–Temporomandibular joint disorders (TMD)
–Cancer-related thrombocytopenia
Possibly Ineffective
–Athletic performance enhancement
–Cancer-related fatigue and pain
–Cachexia in chronic illness
–Critical illness recovery
–Dementia symptom improvement (except possible reduction of sundowning)
–Infertility
–Shift-work sleep disorder
Likely Ineffective
–Benzodiazepine withdrawal symptoms
–Depression (may worsen symptoms in some individuals)
Melatonin and Aging
Experimental observations suggest that removal of the pineal gland accelerates aging processes. This has led to the hypothesis that endogenous melatonin may possess anti-aging properties, though this concept remains under active research.
What are normal melatonin levels?
Normal melatonin levels vary based on age and sex recorded at birth. In general, females tend to have slightly higher melatonin levels than males.
Melatonin production also changes significantly across the lifespan:
–Before birth: A fetus does not produce its own melatonin. Instead, melatonin is supplied through the placenta from the mother.
–After birth: Newborns initially do not synthesize melatonin. They may receive small amounts through breast milk or formula.
–Infancy: A regular melatonin rhythm begins to develop around 3 to 4 months of age, when infants start establishing a sleep–wake cycle.
–Childhood and adolescence: Melatonin levels are highest during childhood and early teenage years, peaking just before the onset of puberty.
–Post-puberty: After puberty, melatonin secretion gradually decreases and stabilizes by the late teenage years.
–Adulthood: Levels generally remain steady until around 40 years of age, after which there is a slow, natural decline for the rest of life.
Most people are unaware of their melatonin levels unless they experience sleep disturbances or related symptoms. When testing is required, a healthcare provider can assess whether melatonin levels fall within the expected normal range for that age group.
Conditions and Disorders Related to Melatonin
Disorders related to melatonin mainly arise due to imbalances in its secretion. These conditions are broadly classified into two types:
Hypomelatoninemia refers to reduced nighttime melatonin levels or a total melatonin output lower than expected for a person’s age.
This condition is commonly associated with circadian rhythm sleep disorders, where the body’s natural sleep–wake cycle is disrupted.
These disturbances may affect:
–The timing of sleep and waking
–Quality of sleep
–Daytime alertness, mood, and overall functioning
Low melatonin levels can make it difficult to fall asleep, stay asleep, or feel refreshed after sleep.
Hypermelatoninemia
Hypermelatoninemia occurs when there is an excess of melatonin in the blood.
–The most common cause is excessive intake of synthetic (supplemental) melatonin.
–Rarely, it may result from overproduction by the pineal gland.
Elevated melatonin levels have been linked to an increased risk of certain conditions, including:
–Anorexia nervosa and other eating disorders
–Hypogonadotropic hypogonadism, where reduced estrogen or testosterone production occurs due to hypothalamic or pituitary dysfunction
–Polycystic ovary syndrome (PCOS), characterized by hormonal imbalance, irregular menstruation, and possible infertility
–Rabson–Mendenhall syndrome, a rare genetic disorder associated with severe insulin resistance and hyperglycemia
–Spontaneous hypothermia with hyperhidrosis, marked by sudden episodes of low body temperature accompanied by excessive sweating
Dosage of Melatonin
Melatonin is commonly taken in doses ranging from 0.5 mg to 10 mg per day.
Since the strength and formulation of melatonin supplements can vary, it is advisable to follow the dosage recommended on the product label to avoid adverse effects. Starting with a lower dose and gradually increasing, if required, is generally recommended to determine individual tolerance and effectiveness.
–For improving sleep quality, melatonin is best taken about 30 minutes before bedtime.
–For correcting circadian rhythm disorders or establishing a regular sleep–wake cycle, melatonin may be taken 2–3 hours before the intended bedtime.
Safety of Melatonin
Research indicates that melatonin is generally safe and non-addictive when used for short-term and long-term purposes in adults.
However, long-term safety data in children and adolescents is limited. Therefore, routine use of melatonin in these age groups is not currently recommended without medical supervision.
Side Effects of Melatonin
Melatonin is usually well tolerated. The most commonly reported side effects include:
–Nausea
–Headache
–Dizziness
–Daytime sleepiness
These effects are typically mild and dose-dependent.
Drug Interactions
Melatonin may interact with certain medications, including:
–Antidepressants
–Blood thinners
–Antihypertensive medications
Caution is advised when melatonin is used alongside these drugs, and medical guidance is recommended.
Melatonin – Quick Revision Points
–Melatonin is a natural hormone mainly secreted by the pineal gland.
–It is also known as the “sleep hormone” due to its role in regulating the sleep–wake cycle.
–Melatonin regulates the circadian rhythm, which follows a 24-hour biological cycle.
–Endogenous melatonin refers to melatonin produced naturally by the body.
–Exogenous melatonin refers to synthetic melatonin used as a dietary supplement.
–Melatonin secretion increases in darkness and decreases with light exposure.
–Peak melatonin levels occur at night, while levels are low during daylight.
–Longer nights (e.g., winter) lead to prolonged melatonin secretion.
–Melatonin acts on the hypothalamus to reduce body temperature, blood pressure, and alertness.
–It helps prepare the body for sleep but does not directly induce sleep.
–Normal melatonin production begins in infants at 3–4 months of age.
–Melatonin levels are highest before puberty and decline after puberty.
–After the age of 40 years, melatonin levels show a gradual physiological decline.
–Females generally have higher melatonin levels than males.
–Melatonin has antioxidant properties and may protect neurons from oxidative stress.
–It plays a role in menstrual cycle regulation.
–Hypomelatoninemia is associated with circadian rhythm sleep disorders.
–Hypermelatoninemia is most commonly caused by excess melatonin supplementation.
–Recommended oral dose of melatonin ranges from 0.5 – 10 mg/day.
–Melatonin is generally safe and non-addictive in adults, with common side effects being headache, dizziness, nausea, and sleepiness.
For Further Reading:
Comprehensive review of melatonin as a promising nutritional and nutraceutical supplement – ScienceDirect
Effect of melatonin supplementation on sleep quality: a systematic review and meta-analysis of randomized controlled trials – PubMed
Status of research on the application of melatonin in insomnia based on bibliometric visualization analysis and development trends
Melatonin supplementation: new insights into health and disease – PubMed
Meta-Analysis: Melatonin for the Treatment of Primary Sleep Disorders | PLOS One
Melatonin: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews
10 Melatonin Mistakes That Could Be Ruining Your Sleep
Melatonin for Sleep: Does It Work? | Johns Hopkins Medicine
Foods High in Melatonin
Melatonin as a Hormone: New Physiological and Clinical Insights | Endocrine Reviews | Oxford Academic
Melatonin and health: an umbrella review of health outcomes and biological mechanisms of action – PMC
A super quick and effective 5 minute arm workout using dumbbells/weights! The full, follow along, workout can be found on my channel. #homeworkout #fitness #shorts
As we age, our metabolism slows down. Anyone over 40 knows this: belly fat becomes more stubborn, and digestion becomes sluggish. This is precisely where this home remedy for bloating comes in.
It combines substances that support your digestion and simultaneously relieve the body—for a noticeably lighter feeling after just a few days.
The power ingredients and their effects
Warm water: Supports digestion and promotes detoxification.
Lemon: Provides vitamin C and activates the body’s own enzymes. … Apple cider vinegar: Promotes fat metabolism and can curb cravings.
Ginger: Warms, stimulates, and gets the circulation going.
Cinnamon: Stabilizes blood sugar levels and gives the drink a pleasant spiciness.
Together, they ensure your body starts the day optimally – completely without artificial additives.
Preparation: Here’s how, step by step:
Warm 250ml of water (do not boil).
Add the juice of half a lemon.
Add 1 tsp of apple cider vinegar.
Add some freshly grated ginger and a pinch of cinnamon.
Stir well and drink on an empty stomach.
This simple routine can activate your metabolism, harmonize your digestive system, and support long-term reduction of belly fat.
10-Day Test: Naturally Lighter
Many report a flatter stomach, less bloating, and more energy in the morning after just a few days. However, it’s important to note: This drink works best when combined with a balanced diet, exercise, and plenty of water.
In conclusion, just one glass in the morning can do wonders for your body. This warm detox drink with lemon and apple cider vinegar isn’t a miracle cure, but it’s a powerful ritual to naturally boost your metabolism, support digestion, and gently reduce belly fat.
Start tomorrow morning—and feel how lighter and more vital your body feels.
I have a brand new podcast episode live, and today we are talking all things skin! 🌟
I’m sitting down with Dr. Mamina Turegano, a triple board certified dermatologist, internist, and dermapathologist based in New Orleans. In this episode, she’s sharing a really refreshing, integrative take on skin health, the kind you don’t usually get at a regular derm appointment. We get into the topics that are all over social media lately, like whether sunscreen is actually safe, the real deal with Botox, and what habits genuinely make a difference for your skin long term.
Here’s what we chat about:
The real story behind the sunscreen-causes-cancer claim and what the benzene contamination scare actually was
Why correlation is not causation when it comes to sunscreen use and skin cancer rates
The truth about chemical vs. mineral sunscreen and what the FDA actually says
A dive into Botox and all about the safety data, the reported adverse reactions, and the emerging research on brain health
Why skincare advancements (hello, peptides) are changing what we actually need procedures for
The non-negotiable basics every skin routine should include
What lifestyle factors are aging your skin faster than you think
The connection between sleep, stress, and skin conditions like acne, eczema, psoriasis, and hair loss
And so much more!
It was awesome getting to talk to Dr. Mamina and I hope you like listening to it as much as I enjoyed chatting with her! If you’ve ever left a derm appointment with more questions than answers, this episode is for YOU ❤️
204: What Your Skin Is Really Telling You | Sunscreen Safety, Botox Risks & Dermatologist-Backed Habits for Healthy Skin with Dr. Mamina Turegano
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If any of my fellow health professional friends are looking for another way to help their clients, I highly recommend IHP. You can also use this information to heal yourself and then go one to heal others, which I think is a beautiful mission. You can absolutely join if you don’t currently work in the health or fitness industry; many IHPs don’t begin on this path. They’re friends who are passionate to learn more about health and wellness, and want to share this information with those they love. You can do this as a passion, or start an entirely new career.
You can use my referral link here and the code FITNESSISTA for up to $250 off the Integrative Health Practitioner program. I highly recommend it!
Thank you so much for listening and for all of your support with the podcast! Please be sure to subscribe, and leave a rating or review if you enjoyed this episode. If you leave a rating, head to this page and you’ll get a little “thank you” gift from me to you. http://fitnessista.com/podcastreview
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If you eat potatoes when they’re cold, as in potato salad, or chilled and reheated, you can get a nearly 40% lower glycemic impact.
If you systematically pull together all the best studies on potato consumption and chronic disease risk, an association is found for the risk of type 2 diabetes and hypertension—but that’s for French fries. Consumption of boiled, baked, or mashed potatoes was not associated with the risk of high blood pressure, but there was still a pesky link with diabetes. Overall, eating potatoes is not related to risk for many chronic diseases, but boiled potatoes could potentially pose a small increase in risk for diabetes. That’s one of the reasons some question whether they should be counted as vegetables when you’re trying to reach your recommended daily servings of fruits and vegetables.
If you look at other whole plant foods—nuts, vegetables, fruits, and legumes (which are beans, split peas, chickpeas, and lentils)—they’re associated with living a longer life. Significantly less risk of dying from cancer, dying from cardiovascular diseases like heart attacks, and 25% less chance of dying prematurely from all causes put together. But no such protection is gained from potatoes for cancer, heart disease, or overall mortality. So, the fact that potatoes don’t seem to affect mortality can be seen as a downside. Now, it’s not like meat, which may actually actively shorten your life, as you can see below and at 1:28 in my video Glycemic Index of Potatoes: Why You Should Chill and Reheat Them.
But there may be an opportunity cost to eating white potatoes, since every bite of a potato is a lost opportunity to put something even healthier in your mouth—something that may actively make you live longer.
So, potatoes are kind of “a double-edged sword.” The reason that potato consumption may have just a neutral impact on mortality risk is that all the fiber, vitamin C, and potassium in white potatoes might be counterbalanced by the adverse effects of their high glycemic index. Not only are high glycemic impact diets “robustly associated” with developing type 2 diabetes, but current evidence suggests that this relationship is cause and effect.
A front group for the potato industry called the Alliance for Potato Research and Education funded a study that found that intake of non-fried potatoes does not affect blood sugar markers, when compared with the likes of Wonder Bread, that is, so that isn’t really saying very much. Foods with a glycemic index (GI) higher than 70 are classified as high-GI foods (high glycemic index foods), and those lower than 55 are low-GI foods. Pure sugar water, for example, is often standardized at 100, and white bread and white potatoes are also way up there as high glycemic index foods. But when you compare them to an intact grain, like barley groats (also known as pot barley), which is a super-low GI food, you can see how refined grains and potatoes are simply no match. Check out the numbers below or at 2:47 in my video.
Is there any way we can have our potatoes and eat them too, by somehow lowering their glycemic index? Well, if you boil potatoes and then put them in the fridge to cool, some of the starch crystallizes into a form that can no longer be broken down by the starch-munching enzymes in your gut, as you can see below and at 3:06 in my video.
However, the amounts of this so-called resistant starch that are formed are relatively small, making it hard to recommend cold potatoes as a solution. But when put to the test, you actually see a dramatic drop in glycemic index in cold versus hot potatoes, shown below and at 3:23 in my video.
So, by consuming potatoes as potato salad, for instance, you can get nearly a 40% lower glycemic impact. The chilling effect might, therefore, also slow the rate at which the starch is broken down and absorbed. So, people who want to minimize dietary glycemic index may consider precooking potatoes and having them chilled or reheated. The downside of eating potatoes cold is that they might not be as satiating as eating hot potatoes. But you may get the best of both worlds by first cooling them and then reheating them, which is exactly what was done in that famous study I profiled in my book How Not to Diet. The single most satiating food out of the dozens tested was boiled-then-cooled-then-reheated potatoes, as you can see below and at 4:09 in my video.
There is actually an appetite-suppressing protein in potatoes called potato protease inhibitor II, but the way you prepare your potatoes makes a difference. Both boiled and mashed potatoes are significantly more satiating than French fries, as shown below and at 4:26 in my video.
That was for fried French fries, though. What about baked French fries? Folks had a big drop in appetite after eating boiled mashed potatoes, compared to white rice or white pasta, which is right where fried French fries were stuck, as well as baked French fries. So, though baked fries may be your BFF, they’re not very satiating.
Doctor’s Note
Just to be clear, you don’t have to reheat. Chilling is the crucial step to dramatically lower the glycemic index, so you can certainly enjoy a cold potato salad. If you’re trying to control your weight, though, you may want to avoid even baked fries.
This is the third in a five-video series on potatoes. If you missed the first two, see Do Potatoes Increase the Risk of Diabetes? and Do Potatoes Increase the Risk of High Blood Pressure and Death?.
Chilling isn’t the only trick to blunt the glycemic impact. You can also add vinegar, lemon, or broccoli.
Stay tuned for the final two videos in this series: How to Reduce the Glycemic Impact of Potatoes and The Healthiest Type of Potato.
Join the resistance! Check out related posts below.
WANT TO LOSE WEIGHT SAFELY THIS PREGNANCY?
You can & safely & its not too late to start doing something even if you are in the 3rd trimester.
I get tons and tons of messages on a daily basis from pregnant women like you who are not happy with how they are feeling about their body. Some have gained a lot of weight because of food aversions, cravings, morning sickness, just being able to eat carbs and not being active much.
They come to me with zero hope and lots of regret and frustration.
If thats you, I’m so glad you are here. I have helped thousands of women turn things around and end up loving their pregnancy body and controlling weight gain and even toning up.
Its crazy to think that just THREE workouts a week could make such a huge difference, but it can.
Ive had over 200K pregnant mamas go through my programs and most of them say they gained less weight in this pregnancy than prior ones that they didn’t exercise like this.
This kind of exercise is the absolute best for pregnancy, for energy, controlled and less weight gain, toning, strengthening the body for labor and so much more.
3 WORKOUTS… are you willing to spend LESS THAN 3 HOURS A WEEK to be able to have a fit and healthy pregnancy that you are proud of and feel confident in?
Its soooo worth it and I would love to help you feel confident and proud in your own skin while pregnant.
Pregnancy is so hard, but you can do things to feel better, look better and prepare your body for an easier and faster labor.
If you need somewhere to start, I have a 21 day Pregnancy jumpstart that may just be what you need.
If you want to control and lessen weight gain safely please know that it’s possible . It’s even possible to safely tone up while pregnant and that’s exactly what I teach you in the challenge.
Most of the ladies that do my programs say they are in better shape while pregnant than ever before.
Dietitians must possess a strong understanding of biochemistry to effectively translate complex metabolic processes into practical dietary recommendations tailored to individual needs and conditions. This knowledge allows them to accurately assess the impact of food components on cellular function, hormonal regulation, and disease prevention, ensuring evidence-based and personalized nutrition plans.
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