What Is Melatonin?

what is melatonin

If you’re looking for a safe natural sleep aid, chances are you’ve heard about melatonin. But, what’s behind this popular sleep aid and could it work for you? Here, we provide some important information that can help you decide.


Melatonin is a hormone produced in the brain from the neurotransmitter serotonin and regulates the body’s circadian rhythms. Melatonin gently eases the mind and body into a state of calm wakefulness in preparation for sleep. Production of melatonin is stimulated by low light conditions. Its levels rise with the moon to promote sleep, and fall as the sun rises to promote wakefulness.

While there are many reasons sleep can be impaired, melatonin has been proven effective for several, including:

Delayed Sleep Phase Disorder

Also known as “night owl” syndrome, delayed sleep phase disorder is most common in young adults. It happens when the body’s internal clock is disrupted, keeping you awake and alert late into the night and then needing to sleep late in the morning, or leaving you feeling sleepy during the day. This can quickly interfere with work or school. In a randomized clinical trial, melatonin helped shift the participants’ circadian rhythms toward a more normal pattern. Results of the study showed that within four weeks the group that took melatonin were falling asleep an average of 34 minutes earlier than the control group.

Jet Lag

Flying across multiple time zones can leave your body clock scrambling to catch up. Melatonin can help offset this unwelcome aspect of travel, so you can quickly acclimate to the new time zone and have plenty of energy to enjoy your trip. How to best use melatonin for jet lag depends on the direction you are traveling. If you are going east, take one dose in the late afternoon on the day you depart and then one at bedtime when you arrive at your destination. When traveling west, eliminate the pre-travel dose and begin supplementing at bedtime for the first four nights of your stay.

Shift Work

Working at night when your body is meant to be asleep shifts the circadian rhythms out of alignment. The body’s day–night cycle influences many aspects of health, such as metabolic and immune function. As a result, shift work can cause physiologic stress that impacts mood and cognitive function and increases risk for metabolic disorders, leading to work performance problems, cardiovascular disease, weight gain, and other health effects. In a study of night shift nurses, 12 weeks of melatonin supplementation improved circadian alignment by 20% and improved symptoms related to poor sleep. Participants reported better work performance and, on average, lost nearly a pound.

Menopause and Aging-Related Sleep Loss

Melatonin levels decline with age, which can cause insomnia or compound the effects of other conditions that impair sleep. Declining melatonin production in middle age brings sleep problems for many women, which are often worsened during menopause. If finding yourself suddenly wide awake before dawn with no hope of getting back to sleep has become part of your new reality as you navigate middle age, melatonin may provide the relief you seek. Melatonin has been found to improve sleep during this time and does so without inducing hangover-like symptoms associated with some prescription or over-the-counter sleep medications. In one study, participants who took melatonin slept an average of 30 minutes longer in the morning compared to a control group. Melatonin also improved the amount of REM sleep, the stage in which dreaming, memory, and emotional processing occurs.

Melatonin and Your Nighttime Ritual

Help melatonin help you by making it part of a calm evening routine that includes a variety of healthy sleep habits. Here are a few easy-to-implement tips for living your best sleep life:

  • Keep a regular sleep schedule. This helps your brain and body maintain normal circadian rhythms.
  • Limit screen time in the evening to reducing exposure to brain-activating blue light.
  • Take a short (10-20 minute) nap to catch up on sleep, when needed. But avoid long naps, as they can upset your sleep schedule.
  • Make your bedroom cool, dark, and comfy to promote deep, restful sleep.  

Cautionary Advice

Though melatonin is a naturally occurring hormone, for some people supplementation can cause side effects, such as headache, dizziness, nausea, and/or drowsiness.

In addition to its sleep-promoting function, melatonin has effects on other hormones. For example, there is some evidence that supplementing with melatonin may suppress ovulation and sperm count.

Before taking melatonin for a sleep problem, check with your doctor to rule out a possible medical cause and to determine if it may interact with other medications you may be taking.

Melatonin supplementation can be an effective, natural remedy for some forms of sleeplessness.

About the author
FemmePharma started as a pharmaceutical research and development company more than 20 years ago. We’ve been reinventing women’s healthcare ever since. Please consult your healthcare practitioner to decide which product best meets your needs.

Filed under: Hormones, Your Body