Melatonin 101: Benefits, Uses, and What to Know Before Taking It

Key Takeaways

• Melatonin is a naturally produced hormone that regulates your circadian rhythm and signals to your brain when it's time to sleep. 
• Melatonin supplements work best for the short-term effects of jet lag or shift work, with lower doses of 0.3 to 4 mg taken 1-3 hours before bed often being more effective than higher doses.
• You can support your body’s production of adequate melatonin by maintaining consistent sleep timing, getting morning sun exposure, and limiting blue light at night.

that {{mid-cta}}

Getting a good night’s sleep is one of the best things you can do for your health, mood, and productivity. Unfortunately, many of us struggle to fall asleep and stay asleep, searching for a supplement to help. Melatonin is widely available and commonly used to help regulate the body’s internal clock and promote sleep.

‍

If you’ve used melatonin or are considering it as a way to support your sleep, it’s important to understand how it works, when it’s helpful, and when it may not be the right choice. 

What Is Melatonin?

Melatonin is a hormone that a small structure in your brain, known as the pineal gland, naturally produces. Its main job is to regulate your body’s internal clock, aka your circadian rhythm, that helps guide your sleep-wake cycle. Its production is largely driven by sunlight, but is also affected by your habits, diet, and environment. 

‍

As the sun begins to set, your pineal gland starts releasing melatonin into your bloodstream, which signals your brain that it’s time to wind down and prepare for sleep. When morning comes and light hits your eyes, melatonin production drops, helping you feel more alert. 

‍

In addition to regulating the sleep-wake cycle, melatonin supports metabolism and glucose regulation, plays a role in heart health and immune function, and may help prevent cancer.¹

‍

Eating late at night and exposure to blue light can suppress melatonin production and delay its effects, making it harder to fall asleep and more difficult to wake up in the morning.² And if you’re traveling across time zones or work second or third shift, you may be more likely to struggle with a dysregulated circadian rhythm and decreased melatonin production. 

How Melatonin Works in the Body

Melatonin acts as a signal to your brain that it's time to start winding down, with the sleepy effects coming two hours or so after its release. Unlike naturally produced melatonin, supplements can cause fatigue and sleepiness, especially when taken at higher doses or during the daytime.³

‍

When melatonin levels rise in the evening, it helps align your internal clock with the actual clock, so you feel sleepy and wake up refreshed in the morning. Melatonin primarily influences sleep onset, not how long you stay asleep, so while it can improve your initial time to sleep, it doesn’t guarantee you’ll stay asleep throughout the night. 

‍

Melatonin also interacts with other hormones in your body, including cortisol. Cortisol typically peaks in the morning to help you wake up and feel energized, while melatonin rises in the evening. Chronic stress and irregular sleep patterns can throw both of these hormones and your sleep-wake cycle out of sync. 

Benefits of Melatonin and Common Uses

While sedatives depress your central nervous system, inducing sleepiness and often grogginess, melatonin’s sleep-inducing effects can help you fall asleep faster and increase the total amount of time you spend sleeping, especially if you struggle with a sleep disorder.⁴

‍

Aside from helping with insomnia, short-term melatonin use can help you fall asleep more easily when your internal clock isn’t aligning with your environment. If you’re traveling across time zones and dealing with jet lag, or working an irregular schedule with night-shift work, melatonin can help your body readjust to falling asleep at unconventional times. 

‍

One small study even found that melatonin supplementation may help improve oxidative damage repair in shift-workers, who have an increased risk of everything from heart disease and type 2 diabetes to breast cancer, colorectal cancer, depression, and anxiety, largely due to circadian rhythm disruptions and decreased endogenous melatonin.^5,6

‍

Other short-term benefits of using melatonin supplements may include restoring your sleep schedule after temporary disruptions, such as an illness or a high-stress event. 

‍

Emerging research is exploring additional benefits of melatonin supplements, including the hormone’s antioxidant properties and effects on various organ systems. More research is needed on the effectiveness and use of melatonin for benefits beyond sleep.⁷

Melatonin Dosage and Timing

The amount of melatonin and the timing of the supplement play a large role in how effective it is at helping you fall asleep. Melatonin can be prescribed, but it’s widely available over the counter in doses ranging from 0.1 milligrams to 10 milligrams, so knowing how much to take and when to take it can feel like a guessing game, but it doesn’t have to be. 

‍

Given that the amount of melatonin your body naturally produces is around 0.1 milligrams, small doses of 0.3-1 milligrams can be highly effective for many people.⁸

‍

But if small doses don’t seem to do the trick to help you readjust after jet lag or getting back to your regular sleep schedule, incrementally increasing the dose could help. Recent research suggests that the beneficial effects of melatonin on reducing time to sleep and total sleep time peak at 4 milligrams.⁹

‍

Timing matters just as much as dosage. Melatonin should be taken between one and three hours before you hope to fall asleep for the best results.¹⁰ If you take it too late, it may be more difficult to wake up in the morning, and if you take it too early, you may find yourself feeling sleepy well before your scheduled bedtime. While using melatonin for a short period to help reset your circadian rhythm, taking it at the same time each night can help it be more effective. 

Potential Side Effects, Risks, and Who Should Be Cautious with Melatonin

While melatonin is generally considered safe for short-term use in most people, a small percentage may experience side effects such as daytime grogginess, sleepiness, headaches, and dizziness.¹¹ Some people report vivid or bad dreams after taking melatonin as well, but there’s no clear reason as to why this happens.¹²

‍

If you’re pregnant, breastfeeding, or take medications like antidepressants, blood pressure medication, or sleep medication or medication with sedative effects, you’ll want to avoid melatonin supplements, or be sure to discuss with your doctor first. Always talk with your child’s doctor before giving them a melatonin supplement. 

‍

Long-term use of melatonin isn’t recommended, as its effects aren’t well understood yet. One recent study found a connection between long-term melatonin use and risk of heart failure and death from all causes. While the study had several limitations and doesn’t establish that melatonin caused these outcomes, it does indicate that more research is needed to assess the safety of long-term melatonin use.¹³

‍

If you do decide to take an over-the-counter melatonin supplement, take care to use a supplement from a reputable brand that’s been third-party tested for potency.  In 2017, one study found that, of 31 melatonin supplements tested, the amount of melatonin ranged from -83% to +478% of what was listed on the label.¹⁴

Natural Ways to Support Melatonin Production

While supplements can help, you can naturally improve melatonin production and support your circadian rhythm with your daily and nightly habits, starting as soon as you wake up. 

‍

Waking up at a consistent time each morning, even on weekends, helps set your internal clock. Then, exposing your eyes to sunlight in the morning helps regulate melatonin secretion, reduces daytime sleepiness, and keeps you feeling more alert throughout the day.¹⁵

‍

Sticking to a set bedtime can help regulate your internal clock and melatonin production, as well as how you spend those last few hours before bed. Reducing your room temperature can help lower your core body temperature more effectively, which is a natural precursor to melatonin production.¹⁶ And while research suggests that all light exposure in the evening can reduce melatonin production, some light waves are more harmful than others. Blue light, such as from screens, reduces melatonin levels more severely and for longer than other light sources, such as red light.¹⁷ Minimizing screen use before bed and using blue-light blocking glasses in the evening hours may help reduce its effects. 

The Bottom Line

Melatonin supplements can be a helpful tool when your internal clock is out of sync with your environment, like when you’re adjusting to jet lag or shift work. Understanding how melatonin works, using the right dose at the right time, and supporting your body's natural sleep rhythm through good sleep habits will give you the best results. Start with the lowest effective dose, be consistent with timing, and combine your supplement use with healthy sleep practices, such as maintaining a consistent sleep schedule, morning sunlight exposure, and limiting evening blue light exposure. 

‍

If sleep problems persist despite trying melatonin and improving your sleep habits, you may want to talk to your doctor to rule out underlying sleep disorders or other health conditions that could be at the root of your sleep struggles.

Learn More With Signos’ Expert Advice

Poor sleep can disrupt glucose regulation, while better sleep supports more stable glucose levels throughout the day. If you're working on improving your sleep habits and want to understand how they're affecting your overall health, Signos can help you track and optimize your metabolic health. Curious about the connection between sleep, glucose, and your body's internal rhythms? Explore more insights on glucose levels and metabolic health on the Signos blog.