Is Melatonin Addictive?

Most people are familiar with melatonin supplements. In fact, you might have a spare bottle of pills rattling around in their nightstands in case of insomnia emergencies. But is it safe to take melatonin every night, or can it cause dependency?

Although some health experts don’t see eye to eye about whether or not the general population should be taking melatonin, one thing appears to be agreed upon across the board: melatonin is not an addictive substance.

Let’s take a closer look at the details about melatonin dependency, how to take melatonin supplements safely, and a bit of sleep science about how it actually works.

Is Melatonin Addictive?

Melatonin is a naturally occurring hormone that our bodies produce each night. This is a good sign that we won’t become chemically dependent or physically addicted to its supplemental form. 

If you currently take melatonin every night for insomnia or poor sleep, it’s possible that your sleep may suffer again once you stop taking it. However, that doesn’t mean it’s addictive.

One hallmark characteristic of addiction is needing more of a substance to feel the same effects (also known as increased tolerance). Melatonin does not have this effect—you won’t need to constantly up your dose to get the same sleep-inducing effects.¹ 

It also does not cause withdrawal symptoms or feelings of  “sleep hangover,” as you may see with many sleep medications.

Although our bodies don’t chemically rely on melatonin supplements to fall asleep,we are naturally dependent on our own melatonin.

Evidence also does not suggest that taking melatonin supplements will suppress our natural ability to produce melatonin.² 

That said, melatonin can be habit-forming. Just as brushing your teeth before bed is a habit, taking a melatonin pill might be one of yours, too. If you solely take melatonin out of habit, it’s probably time to take a break from it and see if it truly benefits your sleep. 

Overall, you don’t want to take too much melatonin or continue taking it forever, as there is not much long-term safety data on the supplement.

Melatonin Supplements: Side Effects and Dosage

The most frequent side effects of melatonin are headache and fatigue (which is usually the desired effect). Don’t take it within five hours of needing to drive. 

Other less common but still reported side effects include low blood pressure, high blood pressure, dizziness, digestive upset, vivid dreams, confusion, mild anxiety, cramps, irritability, and depression. 

Studies have found no significant differences in side effects between people taking melatonin versus placebo.³

Melatonin can also increase the risk of bleeding in those taking it, so people on blood thinners should avoid it or ask their doctor or healthcare provider.

Melatonin Supplements Dosage

Melatonin supplements vary widely in dosages, ranging from 0.1mg to 20mg. 

According to a review paper published in Neurology International, less than 5mg per day of melatonin appears to be safe. However, the authors state that the optimal dosage has yet to be established and that doses of 1mg or lower may be as effective as higher amounts.⁴ 

For those new to taking melatonin, starting at the lowest dose (like 0.5 to 1mg) could be beneficial. The amount of melatonin you take may depend on what you’re using it for (i.e., to treat insomnia or another sleep disorder versus simply as a sleep aid).

Melatonin is sold as a dietary supplement in the United States (in contrast to Japan, Australia, the EU, and the UK, which require a prescription). It’s essential to ensure your melatonin supplement is third-party tested for potency, purity, and quality.

Who Should Not Take Melatonin?

Pregnant and breastfeeding women are not advised to take melatonin, as there is not enough long-term safety data.

People on blood thinning medications or those with autoimmune or seizure disorders should also avoid it. 

Melatonin interacts with several prescription medications, including diabetes medications, anticonvulsants, antiplatelet drugs, oral contraceptives, blood pressure drugs, anti-anxiety medications, and immunosuppressants.

As always, ask your doctor if you’re unsure. 

How Does Melatonin Work?

Melatonin is a naturally occurring hormone produced by the pineal gland, a tiny organ shaped like a miniature pinecone (that’s where its name comes from!) located in the deep center of your brain. 

The pineal gland doesn’t get much action during the daylight hours, but when night time comes around, it gets to work. 

We need the amino acid tryptophan to create melatonin in the body. This is why people (somewhat erroneously) claim that Thanksgiving turkey puts them to sleep.⁵

Tryptophan gets converted into a compound called 5-HTP (5-hydroxytryptophan), followed by a transformation into serotonin, our “feel-good neurotransmitter,” a direct precursor to melatonin.

However, these conversions don’t happen all day long. Darkness is needed to stimulate the pineal gland to produce melatonin.

For people on a conventional sleeping schedule, melatonin is produced in the late evening (maybe around 8-10 pm, depending on the person). Nighttime melatonin levels are about ten times greater than in the morning, preparing your body for sleep by lowering blood pressure, body temperature, and the stress hormone cortisol.⁶ 

Conversely, when light first hits your eyes in the morning, your retina sends a signal to a center in the brain’s hypothalamus called the suprachiasmatic nuclei (SCN). This tells the pineal gland to shut down melatonin production and perform some wake-up duties instead, like raising body temperature and releasing some cortisol to get you going on your day.⁵ 

Both the timing of our sleep-wake cycle and melatonin synthesis are governed by the circadian rhythm, our body’s 24-hour internal clock.

Our circadian rhythms are controlled by light exposure.The SCN in the hypothalamus is responsible for keeping the circadian rhythm’s pace.⁵ 

Ideally, melatonin is only produced after sundown and is halted during the day. However, many things can disrupt this ancient biology, especially artificial light and electronic usage at night. Bright, unnatural lights can significantly delay melatonin production and worsen sleep (yet another reason to stop scrolling social media before bed!).

Melatonin supplements are thought to work best to treat insomnia and for people with sleep disorders or disrupted circadian rhythms, including those working night shifts or traveling across multiple time zones (aka jet lag).^7,8 

Taking melatonin also helps regulate the circadian rhythms of people with insomnia and night owls, especially for reducing sleep onset latency, or how long it takes to fall asleep.⁹ 

Research also suggests that people with autistic spectrum disorder (ASD) may benefit from supplemental melatonin. A meta-analysis of 15 studies found that melatonin use significantly improved total sleep time, sleep latency, and sleep efficiency in people with ASD.¹⁰

Lastly, it’s worth mentioning that melatonin is not just beneficial for sleep—it also exhibits anti-inflammatory and antioxidant properties. For this reason, it’s been studied for its role in improving cardiovascular, cognitive, bone, kidney, and metabolic health.¹¹ 

Is Melatonin Addictive? FAQs