What Is Melatonin, Is it Safe, and Does it Work?

In 2020, U.S. consumers spent a whopping $825,559,397 on melatonin supplements. With a 42.6 percent year-over-year increase (Insider), market analysts believe the COVID-19 pandemic and the associated stress and sleeplessness precipitated the spike. 

With CBD product sales also on the rise and the rampant growth of the kava market, it's clear that better sleep is in high demand. 

Taking melatonin for sleep is now common practice; some people even give it to their dogs. But just because something's popular doesn't mean it works. Before you decide to try melatonin for yourself, you should understand what it is and why so many people believe it induces sleep. 

This comprehensive guide to melatonin will explain the science behind melatonin supplements and explore the efficacy of various melatonin products. But bear in mind: people respond to supplements differently. Our guide does not offer medical advice, and you should always consult with your doctor before starting any new supplement or medication. 

What is Melatonin? 

The human body produces melatonin organically. Often called the "sleep hormone" or the "hormone of darkness," melatonin plays an essential role in the body's natural 24-hour sleep-wake cycle. While it does make you feel drowsy, the build up of melatonin doesn't directly make you sleep.

Melatonin doesn't make you fall asleep sleep—it signals to the body that it's time to prepare for sleep mode.

You can think of melatonin as a parent rounding up the kids at night and telling them to brush their teeth and get ready for bed. Melatonin doesn't put you to sleep; it just relays the message from the brain to the rest of the body that it's bedtime. 

But how does the brain know when to produce more melatonin to prepare the body for shutdown? Much like the entire Star Wars franchise, it all comes down to light versus darkness. 

Melatonin Production and Circadian Rhythms  

While you may need a watch for logistical purposes, the human body is pretty good at keeping time on its own. Like many other creatures living under the Sun, humans use the daylight cycle to "tell time" and regulate sleep. This regulatory process responds to your external environment, making it a circadian rhythm

Melatonin synthesis primarily takes place in the pineal gland, located deep in the epithalamus of the brain. Just like your retina, the pineal gland—often called the "third eye"— has photoreceptor cells that detect light or the lack thereof. 

Illustration of circadian rhythm

In the daytime, the pineal gland senses the sunlight and doesn't produce or secrete melatonin. But once the photoreceptors detect darkness, melatonin production resumes and starts to build up in the blood as it's released from the pineal gland. As previously explained, the hormone's buildup in the bloodstream signals to the body that it's time to sleep. 

After the onset of darkness, the brain releases more and more melatonin until production peaks, typically between 2 a.m and 4 a.m. Then, melatonin synthesis gradually slows during the latter half of the night and stops during daylight. This 24-hour cycle is known as the sleep-wake cycle. 

Natural and Synthetic Melatonin Supplements

In theory, taking a melatonin supplement should increase the melatonin levels in your bloodstream, making you drowsy and instructing the body to start prepping for bed. We'll talk more about the effectiveness of these supplements later, but first, let's explore how they're made. 

Many organisms run on circadian rhythms and use melatonin to regulate their sleep-wake cycles. That means melatonin supplement producers can naturally source the hormone from animal pineal glands. However, the vast majority of melatonin supplements on the market are made synthetically, as melatonin derived from animals can contain harmful diseases.

Is Melatonin Safe?

In the U.S., you can buy melatonin supplements online or at a drugstore or grocery store without a prescription. Classified as a supplement, melatonin isn't as strictly regulated as food and medications by the U.S. Food and Drug Administration. 

According to the National Institutes of Health

"For melatonin supplements, particularly at doses higher than what the body normally produces, there's not enough information yet about possible side effects to have a clear picture of overall safety. Short-term use of melatonin supplements appears to be safe for most people, but information on the long-term safety of supplementing with melatonin is lacking."

Melatonin Side Effects

Many people who use melatonin supplements don't experience significant side effects, though some report headaches, dizziness, drowsiness, and nausea. 

Less commonly, melatonin may cause side effects like irritability, confusion or disorientation, low blood pressure, and depression or anxiety symptoms, according to the Mayo Clinic

Is Melatonin Addictive?

Melatonin is unlikely to cause dependence, habituation (diminishing response), or the hangover effect. This contrasts with many medications or "sleeping pills" doctors prescribe for patients with more severe sleeping problems. These medications, such as benzodiazepines, can lead to addiction or dependence. 

Melatonin and Alcohol 

According to the American Academy of Sleep Medicine (AASM), 68 percent of Americans have lost sleep due to drinking alcohol past bedtime. 

If drinking alcohol makes it hard for you to fall asleep, you may wonder, can taking a melatonin supplement counter the effects and help you doze off? 

Alcohol consumption can decrease your body's natural melatonin production and interfere with your established sleep-wake cycle. But that doesn't mean taking melatonin after drinking is a quick fix to help you sleep. 

Mixing melatonin and alcohol can be dangerous.

According to Healthline, side effects of the combination can include drowsiness, loss of focus, dizziness, anxiety, irritability, and increased blood pressure. Moreover, mixing the two substances can affect your liver's ability to produce crucial enzymes and lead to further complications. 

Melatonin and Medications

As with any new supplement or medication, you should talk to your doctor about potential drug interactions before using melatonin for sleep. You can learn more about possible drug interactions with melatonin here.

Does Melatonin Work? 

We've established that melatonin is generally safe for short-term use by adults, but do melatonin supplements actually do what manufacturers suggest? 

If you read product descriptions or ads for melatonin gummies and other melatonin products, you'll see claims that taking melatonin before bed can help you fall asleep quicker. Many brands also say the supplement can help you stay asleep or get better quality sleep. 

So does it work? The short answer: maybe. The answer also depends on your expectations and what problem you're trying to fix. 

Efficacy Studies

Over the years, many researchers have conducted trials to measure the efficacy of melatonin supplements for falling asleep faster, countering jet lag, treating insomnia, improving sleep for shift workers, and more. While more research needs to be done to confirm and measure melatonin benefits, the following studies have shown promise: 

  1. A randomized control trial in 2018 found that melatonin supplementation, in combination with behavioral sleep-wake scheduling, improved objective and subjective measures of sleep disturbances and sleep-related impairments for patients with delayed sleep-wake phase disorder (DSWPD). 

  2. In 2014, Samueli Institute used their Rapid Evidence Assessment of the Literature (REAL) process to find 35 randomized controlled trials on melatonin efficacy meeting their criteria. The systematic review of materials concluded that:

    "The use of melatonin by healthy adults shows promise to prevent phase shifts from jet lag and improvements in insomnia, but to a limited extent. For the initiation of sleep and sleep efficacy, the data cannot yet confirm a positive benefit...Melatonin in a wide array of preparations and amounts demonstrates few significant and limiting adverse events."
     
  3. In 2013, researchers performed a meta-analysis of 19 PubMed studies including a total of 1,683 subjects. Their meta-analysis concluded that melatonin can decrease the time it takes to fall asleep, increase sleep duration, and improve sleep quality. 

    However, the reviewers noted that the effects are modest and the "absolute benefit of melatonin compared to placebo is smaller than other pharmacological treatments for insomnia."
     
  4. The 2002 PubMed article Melatonin for the prevention and treatment of jet lag reviewed 10 randomized trials in airline staff, passengers, or military members. Nine of the 10 trials included in the study reported that taking melatonin close to your chosen bedtime at your destination (from 10 p.m. to 12 a.m.) decreases jet lag when crossing five time zones or more. 

      The American Academy of Sleep Medicine's Official Stance 

      As of 2021, the AASM recognizes strategically-timed melatonin supplementation as a treatment option for "sleep-timing" problems like jet lag and work shift disorders. 

      However, the organization does not currently recommend clinicians use melatonin supplements as a treatment for adult chronic insomnia, as its efficacy requires more research. 

      Conclusion

      As the market for melatonin continues to grow, the scientific community will likely ramp up efforts to assess the supplement's effectiveness. Down the road, we'll hopefully have more data measuring the benefits of both short-term and long-term melatonin use for a wide variety of sleep disorders. 

      The good news is, melatonin supplements show potential as a tool for sleep treatment. Especially if combined with good sleep hygiene, taking melatonin could prove useful for you and is generally safe for most adults. But remember, people respond to treatments differently, so what works for one person may not work for another.

      If you do decide to give melatonin a try, be sure to read our Complete Guide to Melatonin Supplements and Dosages