The world of hormone health is both fascinating and complex, and there’s one hormone that’s often overlooked when it comes to the numerous benefits it provides to our bodies: Melatonin. 

“This powerhouse can be found throughout the body regulating a ton of its essential functions.”

Many of my patients are surprised to learn that it isn’t only a sleep aid. Or even that it is a hormone. As it turns out, this powerhouse can be found throughout the body regulating a ton of its essential functions. So, if you’re already taking melatonin on the regular, or interested in how it might impact your overall health, then there’s lots to learn.

Below, I’m unpacking the beauty of the hormone melatonin. You’ll learn how it does so much more than just facilitate a good night’s sleep. From its origins and functions, to ways to naturally enhance its production for optimal wellbeing, we’ll explore everything about melatonin — and I’ll try to answer the most commonly asked questions along the way.


What is melatonin?

Melatonin, often called the “hormone of darkness” or “hormone of sleep,” is made primarily by the pineal gland, a pea-sized structure nestled deep within the brain. Melatonin is produced in response to light signals perceived by our eyes, so it’s no surprise that its production is intricately linked to the light-dark cycle, with levels rising in response to darkness (at sunset) and plummeting with the onset of light (at sunrise). This intimate relationship to light serves as the cornerstone of melatonin’s role in regulating our sleep-wake cycle, also known as the circadian rhythm.

“Melatonin is produced in response to light signals perceived by our eyes, so it’s no surprise that its production is intricately linked to the light-dark cycle.”

However, melatonin’s influence extends well beyond sleep, permeating various aspects of our health. It’s important to know about this “pool” of other sources of melatonin beyond the pineal gland — and how they contribute to its fascinating abilities to support our bodies in areas beyond sleep.


Where does melatonin come from?

Melatonin was first discovered in 1958 by Yale dermatologist Dr. Aaron B. Lerner and his colleagues, who stumbled upon it while studying lightening agents for the skin. Their work laid the foundation for its consideration within the sleep-wake cycle. A significant amount of research and findings have been gathered and amplified in the 21st century by notable researchers like Dr. Russel Reiter and so many others, and this research is ongoing as we’ve learned more about melatonin in the past few years.

Interestingly enough, melatonin isn’t only found in the brain in response to light signals, it’s actually widespread throughout other areas of the body, including the liver, kidney, adrenal gland, heart, thymus, genital glands, placenta, uterus, skin, platelets, and also within different types of cells that support our immune system. One of the greatest extra-pineal concentrations of melatonin is in the gastrointestinal tract, and it’s even found in almost all of our body fluids, including breast milk!

“One of the greatest extra-pineal concentrations of melatonin is in the gastrointestinal tract, and it’s even found in almost all of our body fluids, including breast milk!”

With this much melatonin, it’s clear that it does more than just support our circadian rhythm. Its prevalence across our different systems is a big reason why melatonin packs a super punch of so many benefits. Let’s learn more.


The multifaceted functions of melatonin

So, how exactly does melatonin help to regulate sleep? And what else can it do? We’ve put together a list of melatonin’s most essential functions with more information on each.

  1. Regulating sleep: Melatonin’s most renowned role is in promoting restful sleep. By signaling to the body that it’s time to wind down, melatonin helps initiate the onset of sleep and may support sleep duration and quality throughout the night.
  2. Boosting immunity: Melatonin serves as a potent immunomodulator, enhancing the function of immune cells and promoting a robust immune response against infections. Its anti-inflammatory properties also help to temper excessive immune reactions, fostering a balanced immune system.
  3. Antioxidant protection: As a powerful antioxidant, melatonin scavenges harmful free radicals and mitigates oxidative damage to cells and tissues. This antioxidant shield plays a crucial role in preserving cellular integrity and combating the effects of aging and disease.
  4. Modulating mood: Melatonin influences mood and emotional regulation. Disruptions in melatonin signaling have been linked to mood disorders such as depression and anxiety, highlighting its importance in maintaining emotional equilibrium.
  5. Enhancing cognitive function: Melatonin’s neuroprotective effects extend to cognitive function, where it helps to safeguard against neurodegenerative diseases. By promoting neuronal survival, synaptic plasticity, and supporting the integrity of the blood-brain barrier, melatonin enhances learning, memory, and overall cognitive performance.
  6. Supporting cardiovascular health: Melatonin plays a crucial role in maintaining cardiovascular health by regulating blood pressure, cholesterol levels, and vascular tone. Its anti-inflammatory and antioxidant properties help to protect against cardiovascular diseases such as hypertension and atherosclerosis.

What happens to melatonin production as we age?

When we zoom out to take a look at how melatonin is made, and not just where we find it, we find that newborn babies produce very little melatonin right after birth while they’re adjusting to the outside world. Throughout the course of a lifetime, melatonin production peaks in early childhood, and then starts to decline after puberty. As we get older, we produce less and less melatonin each night.

“Melatonin production peaks in early childhood, and then starts to decline after puberty.”

This follows the same pattern that we see with other hormones like estrogen, progesterone, and testosterone which also decline in natural production as we age. Other factors that can affect melatonin production beyond age include diet, metabolism, shift work, traveling between time zones, jet lag, and even certain medical conditions. You’ve probably experienced at least one of these firsthand, so you know how draining and disorienting it can make you feel.


Tips for naturally enhancing melatonin production

On a typical day, our body starts initiating melatonin production at sunset, and it naturally peaks in production around 2–4 a.m. before continuing its decline as our body prepares to wake up the next morning. Little melatonin is present when you wake up, as the wake-up hormone cortisol starts to prepare your body for the day. This can become dysregulated for a variety of reasons — so if you are having trouble sleeping, or experiencing the impact of low melatonin in one of the systems we mentioned above, read on for tips to naturally boost its production.

  1. Optimize your sleep environment: Create a conducive sleep environment by minimizing exposure to artificial light, particularly blue light emitted by electronic devices, in the evening. Invest in blackout curtains to promote darkness and block out external light in your bedroom.
  2. Establish a bedtime routine: Establish a consistent bedtime routine to signal to your body that it’s time to wind down. Engage in relaxing activities such as taking a warm bath, practicing gentle yoga, stretching, or breath work, or even listening to soothing music to relax your body and mind.
  3. Limit caffeine and alcohol: Limit consumption of caffeine and alcohol, particularly in the hours leading up to bedtime, as they can disrupt sleep patterns and inhibit melatonin production.
  4. Practice stress reduction techniques: Incorporate stress reduction techniques such as deep breathing exercises, mindfulness meditation, or yoga into your daily routine to promote relaxation and lower stress levels.
  5. Expose yourself to natural light during the day: Spend time outdoors during the day, especially in the morning, to expose yourself to natural sunlight. Natural light exposure helps to synchronize your circadian rhythm and promote melatonin production later in the evening.
  6. Limit screen time before bed: Minimize exposure to screens, including smartphones, tablets, and computers, at least a few hours before bedtime. The blue light emitted by these devices can suppress melatonin production and disrupt your sleep patterns. We know we already said this before, but it’s important!
  7. Maintain a consistent sleep schedule: Stick to a regular sleep schedule by going to bed and waking up at the same time every day, even on weekends. Consistency helps to regulate your body’s internal clock and optimize hormone production.
  8. Ensure optimal magnesium intake: Include magnesium-rich foods such as leafy greens, nuts, seeds, and whole grains in your diet, as magnesium plays a role in melatonin synthesis and can help improve sleep quality.

Answering your questions about melatonin supplements

It’s always best to optimize natural melatonin production as much as possible before considering supplementation. If you’re still interested in taking melatonin, you should talk to your doctor to decide if supplementing with anything — including melatonin — is right for you. 

There are so many things to consider when a patient asks about melatonin supplementation. To be honest, it isn’t my go-to recommendation when it comes to sleep, but it’s certainly an important tool in the toolbox to consider for the right patient at the right time. After supporting and dialing in on the important lifestyle practices noted above to consistently enhance natural melatonin production, my conversation with a patient may explore different types of supplementation options including melatonin.

“There are so many things to consider when a patient asks about melatonin supplementation.”

Since there’s lots to consider, I’ll let you in on some topics of conversation that I might broach with a patient when deciding on a supplement routine. This should help you prepare for any conversation you have with a doctor about supplementation.

  • It’s typically not recommended for use in children and young adults due to its effects on other hormones being produced in the body to support development. 
  • Do your research. Be mindful of over-the-counter melatonin supplements, as recent research suggests that some brands are not transparent about claims on dosage, purity, and potency. Many are also laden with unwanted fillers. (TGT has a guide of vetted supplements if you want to start there!)
  • More is not always better. Your body typically makes less than 1mg of melatonin each night.  While there are many melatonin supplements out there marketing dosages much higher than this, most physiologic and therapeutic dosages are between 0.1–3mg, where the higher doses may be indicated short term for things like jet lag. A sweet spot dosage for physiologic support is around 0.3mg.
  • Drug interactions exist. Always talk to your doctor about taking melatonin, as it can interfere with antidepressants, anti-seizure medications, birth control, blood pressure medications, diabetes medications, and more. 
  • How to use it: When taken 30-60 minutes before bed on an empty stomach, melatonin supplements have a half-life of approximately 20-40 minutes or so, and lasts in your system for about 4-5 hours. 
  • Common side effects experienced include daytime sleepiness, headaches, GI upset, vivid dreams. It’s typically recommended to start with the lowest possible dosage and slowly titrate up. If someone is experiencing any of the above symptoms, they may have taken too much and should discuss this with their doctor.
  • Regarding therapeutic dosing, there are times when your doctor may recommend higher doses — also known as therapeutic dosages — to support a specific situation or condition.  For example, I’ve seen doctors recommend higher nightly dosages in patients to support fertility & reproductive health or immune dysregulation, as well as different hormonal or GI conditions that may benefit from melatonin support. Your doctor can help you decide if this is right for you.
  • If strongly considering supplementation, talk to your doctor about phytomelatonin — melatonin that’s derived naturally from plant sources — due to its increased antioxidant potential and anti-inflammatory effects than synthetically derived melatonin supplementation.

Final thoughts

While melatonin is an important hormone for circadian regulation and sleep optimization, it’s easy to forget that it also serves many important functions beyond sleep as a healing hormone for decreasing inflammation, improving cellular health and repair, and beyond.

The next time you get ready for bed, remind yourself that a great night’s sleep is a healthy start to a beautiful day tomorrow. Optimizing your melatonin support can help you sleep soundly, and feel better in your moods, health, your mind, and even your heart.


Dr. Jaclyn Tolentino is a board-certified family physician who currently serves as a Lead Physician at Love.Life. As a women’s health & hormone expert, she’s been featured in Vogue, the Wall Street Journal, and Women’s Health.