Disclaimer: None of the information in this article constitutes medical advice, and is just the opinion of the writer(s). We recommend that patients follow their doctor’s guidance in regard to melatonin supplementation.
Melatonin is one of the most popular supplements for sleep. It’s cheap and effective, and sold by thousands of retailers online and in-person.
But is melatonin proven to be safe in research studies, or are there health risks associated with its use? Can taking a melatonin supplement shut down the body's natural production of melatonin? What's the safe dosing range of melatonin? And is melatonin safe for children to take?
In this article we'll answer all of these questions and more as we review clinical studies on the safety and toxicity of melatonin in both adults and children to determine if it's safe for daily use as a supplement.
We'll also determine the safe dosage range for this supplement, investigate whether taking it orally will affect the body's natural production, and share our top melatonin supplement pick.
Research on Melatonin Safety
Melatonin is one of the safest over-the-counter (OTC) dietary supplements. It has been proven non-toxic at all doses, even much higher doses than would be included in a supplement. Researchers couldn’t even find an LD-50 dose (lethal dose for 50% of subjects) for melatonin in animal studies which is uncommon, and shows how safe this compound is even at doses many factors higher than you’d get in a supplement.
We can conclude that melatonin is safe and non-toxic for adults, but there are two groups that may wish to avoid it: men planning to have a child in the near future, and people with blood sugar issues.
A clinical trial published in the Journal of Andrology found that some men taking a daily melatonin dose of 3 milligrams (mg) experienced negative changes to their semen quality. This study hasn’t been replicated and only had eight participants, so we don’t think it’s conclusive or particularly concerning.
Another clinical trial reported that melatonin supplementation negatively impacted glucose tolerance. Participants had an increased blood sugar response to glucose after taking melatonin.
A medical review published in the Journal of Clinical Sleep Medicine found serotonin in 8 of 30 melatonin supplements tested. Serotonin is a neurotransmitter that's not FDA-approved for use in dietary supplements.
This research suggests that men planning to have a child, individuals who are diabetic and individuals who are pre-diabetic may benefit from speaking with their doctor prior to using melatonin. The serotonin tests show that it's important to buy melatonin from a reputable supplier, and ideally one that publishes product testing.
We Tried Melatonin Ourselves
As one of the authors of this article (Calloway), I wanted to share my experience using melatonin.
I've been using melatonin as a single-ingredient supplement or in multi-ingredient supplements for sleep for years, and haven't experienced any negative effects or any negative changes to my bloodwork.
The only (very mild) side effect I've experienced in some cases is a slight drowsiness if the melatonin dose is too high.
I prefer a dose of 0.5 mg as shown in the image above.
I generally try to take melatonin soon after sunset to optimize my circadian rhythm. I've found that taking it too late in the night increases the chance I'm drowsy in the morning.
Do Supplements Shut Down Natural Production?
The body naturally produces and regulates melatonin levels to optimize sleep-wake cycles.
People are often curious about whether taking melatonin as a supplement can affect their natural production of melatonin. Thankfully, this has been studied in clinical trials.
A 1997 clinical trial found that taking oral melatonin supplements does not impact the body's production of melatonin. Even at doses as high as 50 mg daily, which is a significantly higher dose than is included in most supplements, there was no impact on the body's natural production of melatonin.
This suggests that there should be no negative impacts to sleep after discontinuing melatonin use, and that there is no risk that trying melatonin will cause negative changes to sleep.
What's a Safe Melatonin Dose?
While some melatonin supplements provide as low as 300 micrograms (mcg), there are plenty of OTC melatonin supplements that contain 20 mg or higher.
Melatonin is sold at such a wide range of doses that it can be confusing to consumers how to choose the right dose.
While some studies have shown melatonin to be effective at as high a daily dose as 20 mg, we generally recommend a daily dose of 10 mg or below.
Doses as high as 100 mg have been used in patients with no adverse effects, so even doses that high are likely safe, but we haven’t come across much data suggesting that higher doses are more effective beyond a 10 mg limit.
Interestingly, a woman actually tried to overdose intentionally on melatonin by taking 100 mg at one time, but the only effects she experienced were drowsiness and a slight pulse elevation, according to Poison Control.
Is Melatonin Safe for Children?
Because melatonin has such a favorable safety profile, there is actually a significant amount of clinical studies on melatonin use in children.
A medical review on melatonin to treat sleep disorders in children concluded that melatonin is safe in healthy children, but should be avoided in children with immune disorders due to how melatonin interacts with the immune system.
A long-term clinical trial on melatonin’s safety in children with ADHD found that its use entailed “no safety concerns regarding serious adverse events” and the children in the trial were using melatonin for years.
A medical review published in the International Journal of Pediatrics states that "significant side effects of melatonin in children have not been reported." This review analyzed data from over 100 clinical trials on the topic.
Overall it seems as though melatonin is safe for use in kids, but we'd recommend that parents speak with their child's doctor before recommending it.
Is Melatonin Safe During Pregnancy?
Pregnant women are often extremely cautious about supplements, because supplements they ingest can impact the health and development of their child.
A medical review of melatonin use during pregnancy found no adverse effects, and even suggested that melatonin supplementation may protect the child from adverse health outcomes later in life such as cardiovascular and neurological diseases.
We believe that due to the safety risks, no supplement should be recommended across-the-board to pregnant women, and that pregnant women should speak with their doctor about whether melatonin supplementation is a good choice for them.
Is It Safe To Take Melatonin Every Night?
As we’ve established in prior-linked research, melatonin has a fantastic safety profile and is safe for adults in doses up to 100 mg, but ideally at or below 10 mg as an effective dose.
People are often curious about whether melatonin can be addictive. They worry that if they take melatonin every night, they may become dependent on it to sleep in the future.
Fortunately, there is no evidence of tolerance or addiction potential based on a thorough medical review on the topic. There was no tolerance developed to any dose of melatonin.
This makes sense logically, since as we established previously, melatonin supplementation doesn’t affect the body’s production of melatonin. So even if someone were to take a relatively high daily dose of melatonin like 20 mg, their body would still be producing the same amount of melatonin as usual the day they stopped taking the supplement.
Our Clean Sleep Picks
Ritual BioSeries Melatonin is our top premium sleep supplement.
It provides an effective dose of melatonin, which is clinically shown to improve sleep quality, and which is arguably the best-studied compound for sleep support.
Nolah Weighted Bamboo Blanket is a great option for consumers who prefer non-supplement solutions for sleep. Weighted blankets are clinically shown to improve sleep quality in both older adults and in children, and early research suggests they may also reduce anxiety.
Both of the products recommended in this section are entirely free of ingredients or materials that we consider to be unhealthy.
