Sleeping pills beside glass of water and alarm clock

3 Reasons To Be Cautious About Melatonin

What Is Melatonin and How Does It Work?

Your circadian rhythm is the innate rhythm of your body involved in the 24-hour day. The daily habits you have around waking up, eating, activity, and sleeping are all partly regulated by this natural cycle. The center of your circadian rhythm is a small cluster of cells in the hypothalamus called the suprachiasmatic nucleus (SCN).

Melatonin is an important human hormone that plays an essential role in circadian rhythm. It is secreted by a gland in your skull called the pineal gland. Let’s see how it does its job to regulate sleep and wakefulness.

The Role of Melatonin in Regulating Sleep-Wake Cycles

Melatonin levels rise and fall during the 24-hour day. Its levels are lower when you’re exposed to daylight and higher when the daylight fades. The levels rise in the evening to create a sense of sleepiness and relaxation so you can feel rested and naturally fall asleep.

The pineal gland secretes melatonin when the SCN stimulates it in the brain. Nerves detect the amount of light your eyes see at any time and “tell” the SCN.

Once light levels reduce in the evening, the SCN signals to the pineal gland to make melatonin. This process works automatically and determines when you are more likely to feel sleepy or wake up.

Tired young woman reaching over to shut off alarm clock

Factors That Affect Melatonin Production

Melatonin production is almost entirely regulated by light exposure. As light levels lower in the evening, melatonin levels increase to allow for improved sleep. If you were in a dark room, your melatonin levels would stay up, and you would not be able to sleep as well.

Other factors that affect melatonin production include:

  • Exposure to light from tablets, phones, and computers in the evening will impair melatonin secretion.
  • Shift work and night shifts can impact the timing of melatonin.
  • Traveling across time zones will cause a lag in melatonin release from the pineal gland, which takes up to 5 days to stabilize.
  • Levels of melatonin decline with normal aging. This may explain the poorer quality of sleep in older persons.

Supplemental melatonin is available over the counter to offset any sleep problem you may have because of circadian rhythm upsets or normal aging.

Why Melatonin May Not Be a Suitable Sleep Aid for Everyone

Melatonin is generally considered safe and has no known addiction potential. Even so, anything can be addictive from a behavioral aspect. You can become dependent on melatonin so that, if you stop taking it, you may have difficulty sleeping until your pineal gland adjusts to the change.

There are a few people who cannot take melatonin. Melatonin allergies are possible, making it impossible to handle the supplement safely. It should be used cautiously in kidney and liver disorders due to potential safety issues. It is not recommended in breastfeeding or pregnancy and for those with autoimmune disorders, like rheumatoid arthritis or lupus.

Potential Side Effects of Melatonin

The most common side effect of melatonin is sleepiness. You can be groggy in the morning if you take it late at night. Minor side effects like rash, stomach upset, and headache can occur if you take too much (more than 5 mg per night). Some people get nightmares when taking too much of the supplement. It is not believed to be fatal, no matter the amount you take.

Risks Associated with Long-Term Use of Melatonin

Taking melatonin in the long term does not lead to addiction. You may, however, find it harder to sleep if you don’t take it one night. This is because your pineal gland may not be able to adjust quickly and make enough natural melatonin for effective sleep.

Men who take melatonin for extended periods may have decreased sperm quality. The hormone does act on the testes to inhibit testicular function; however, most men will not notice anything. Long-term melatonin use does not cause erectile dysfunction or low libido.

Young woman sleeping peacefully in bed at night

Natural Alternatives to Melatonin

Melatonin is a natural hormone that does not need to be used as a supplement in most cases. It has uses in the aging population, neurodegenerative diseases, and traumatic brain injury; however, healthy people generally make enough of the hormone without taking supplements.

Lifestyle Changes to Promote Healthy Sleep

There are things you can do that involve no medicine and will help you sleep more easily when you want to:

  • Sleep in your bed at all times and use the bed only for sleep or sex. Do not work or watch television in bed.
  • Sleep in a dark environment with little noise. White noise machines and nature sounds are perfectly fine if they help remove ambient noise.
  • Avoid screens (tablets, computers, and phones) before bedtime because this can reduce melatonin levels.
  • Get plenty of exercise and sunshine during the day. This helps improve sleep quality and mood.
  • Sleep in a cool room (about 66 degrees) with blankets to warm you if you get cold. Cooler rooms are better for your sleep quality.

Other Supplements That Aid in Sleep

If you need to take a sleep-inducing supplement without melatonin, there are many options for you to consider to help relax you before sleep:

  • Ashwagandha
  • Chamomile
  • Valerian
  • Lavender
  • Magnesium
  • Passionflower
  • Glycine

These are often combined to make various preparations for sleep – including tea, capsules, or gummies.

What Addiction Means and Whether Melatonin Can Be Addictive

Addiction to a medication can happen in two ways.

  1. You can have a physical dependence on a drug accompanied by activation of the brain’s pleasure centers, leading to withdrawal symptoms if you don’t keep taking the drug.
  2. You can be emotionally attached to a specific drug because you have come to depend on it. The drug isn’t inherently addictive but becomes something you come to expect and need.

Melatonin does not activate the pleasure pathways, and you won’t need more over time to get the same effect. You also won’t have withdrawal symptoms seen with most addictive medications. On the other hand, you may have difficulty falling asleep after you have become accustomed to taking it.

Different Opinions and Studies on Melatonin Addiction

Multiple studies on animals have shown that melatonin does not exhibit the features of an addictive drug. In humans, melatonin is used for those with addictions to help ease anxiety and enhance sleep.

While melatonin has no innate addictive potential, it isn’t completely safe. Because it is used to treat anxiety, pain, and insomnia, it is easy to become emotionally dependent.

How to Use Melatonin Responsibly

Melatonin is an over-the-counter supplement, so it is easily accessible. Even though it is safe to take under most conditions, be sure your doctor knows this is what you’re taking. Take the same amount (1 to 5 mg daily) before bedtime unless you are actively using it under the guidance of a healthcare professional.


Can melatonin cause withdrawal symptoms?

There are no known withdrawal symptoms if you stop taking melatonin; however, you may not sleep well if you have become used to taking the supplement and don’t take it one night.

Is melatonin safe for children and teenagers?

The FDA has not approved melatonin for children or teens; however, most pediatricians say it can be used safely in children above 5. The dose may be reduced to accommodate a younger child’s size.

How does melatonin interact with other medications?

Melatonin may interact with other drugs and supplements:

  • Antipsychotics. You may reduce the incidence of movement disorders when you take melatonin alongside these medications.
  • Antidepressants. Most antidepressants have minimal issues with melatonin; however, it can reduce the effectiveness of fluoxetine and desipramine, based on an animal study.
  • Benzodiazepines. Melatonin may reduce dependence on a benzodiazepine, but it could cause excess sedation if taken along with a sleep medication containing a benzodiazepine.
  • Birth control pills. Birth control pills increase the melatonin level in your body, making it more likely that you’ll accidentally take too much melatonin.
  • Beta-blockers. These heart medications can lower melatonin levels in your body, making it more likely that you’d need more of the supplement for sleep.
  • Other blood pressure medications. Calcium-channel blockers may lower melatonin levels but will still effectively lower blood pressure.
  • Blood thinners. Melatonin may increase the chance of bleeding if you take warfarin simultaneously.
  • Interleukin-2. This is used for cancer. When combined with melatonin, cancer patients taking this drug had a better survival rate.
  • NSAIDs. Ibuprofen and other NSAIDs might lower the effectiveness of melatonin.
  • Steroid drugs. Steroids and other immunosuppressive drugs are less effective when taken with melatonin. Do not take melatonin with these medications.


  • Christine Traxler, M.D.

    Dr. Traxler has over 17 years of experience writing in the medical field. She specializes in medical, health and wellness, dermatology, pregnancy, nursing, and medical assisting. She has a B.S. in Biochemistry and a Medical Doctorate. Visit LinkedIn page.

    View all posts