How Much Melatonin Should You Be Taking?

Most adults need between seven and nine hours of sleep every night, according to Healthline. Although these numbers may vary from person to person, healthy sleep is vital and significantly impacts your learning and memory. Unfortunately, many people don't get enough sleep and have to resort to taking sleep supplements, like melatonin.

A 2017 study published in the journal Current Neuropharmacology describes melatonin as a natural hormone produced by the pineal gland in your brain, which induces fatigue and sleepiness while reducing sleep latency. Although melatonin doesn't make you sleep, it plunges you into a state of wakefulness that helps promote sleep as melatonin levels rise, according to Johns Hopkins Medicine. While your body naturally produces this hormone, supplementing might help you battle insomnia and other sleep disorders.

Despite its significant importance in regulating the human sleep-wake cycle, melatonin also fulfills other important functions in the body — it helps regulate metabolism, body temperature, and blood pressure, per this 2018 study published in the journal Endocrine Reviews. 

For many, access to it is easy since it's available over the counter (via SleepFoundation.org). In fact, melatonin usage increased by more than 2% between 2017 to 2018 among men and women across all age groups, as revealed by the National Institutes of Health. But how much melatonin should you be taking?

The FDA doesn't have the authority to approve dietary supplements, like prescription drugs, according to the Food and Drugs Administration (FDA). Rather, supplement manufacturing companies are mandated by the Federal Food, Drug, and Cosmetic Act (FD&C Act) to ensure their product meets the necessary standards. Therefore, arriving at a safe dose of melatonin may depend on various factors, including body weight, age, and personal sensitivity, as per the SleepFoundation.org. 

To understand the correct dosage, it would be best to follow your doctor's guidelines to prevent unwanted melatonin side effects. As a guide, the Cleveland Clinic advises starting with 1 mg, increasing by an extra 1 mg weekly, until the time it takes for you to fall asleep reduces. According to the National Health Service (NHS), taking a single 2 mg tablet can be enough if you have sleeping problems. However, it might take a bit before the supplement takes effect. Therefore, taking it one to two hours before bedtime is advisable. Be sure to swallow the tablet whole rather than chewing or crushing it.

While some sources advise taking 1 to 2 mg daily, it's crucial to know the upper limit, especially in the absence of official guidelines from the FDA. The experts at Medical News Today warn not to exceed 5 mg unless your doctor says otherwise.

The long-term effects of melatonin are still unknown, according to the SleepFoundation.org. However, it is considered an effective treatment for sleep disorders, like insomnia and jet lag. In fact, various short-term side effects of melatonin can include low blood pressure, anxiety, tremors, confusion, and irritability, per Medical News Today. 

As melatonin also stays active for longer in older people, they might also experience daytime drowsiness (via the National Center for Complementary and Integrative Health). Therefore, it's best to avoid using heavy-duty machines at work or performing high-risk activities requiring alertness, such as driving (per Mayo Clinic).

As for drug interactions, there are 278 drugs that can interact with melatonin, according to Drugs.com. This includes Xanax and Benadryl. Experts don't recommend taking melatonin with food or under the influence of alcohol. Additionally, those with glaucoma, depression, or liver disease should not take melatonin without consulting a doctor first.