The current clinical consensus is that daily melatonin consumption is considered safe. However, according to a 2020 article published in Antioxidants, more research is needed to determine the correct dose and time and understand potential long-term effects.
Regardless of whether it truly helps with sleep or not, Dr. Ramkissoon doesn't recommend taking melatonin long-term.
Short-term use of melatonin may not be harmful but there is insufficient evidence on its long-term safety, according to the National Center for Complementary and Integrative Health. And in some cases, relying on melatonin could simply mask another problem.
What is a safe melatonin dose? According to Michael Grandner, director of the Sleep and Health Research Program at the University of Arizona, “melatonin is very safe if taken in normal doses,” which is anything between 0.5 mg and 5 mg.
Do not use melatonin if you are pregnant or breastfeeding or have an autoimmune disorder, a seizure disorder or depression. Talk to your health care provider if you have diabetes or high blood pressure.
In the UK and most of Europe, it's classed as a medicine, not a health supplement and as such, requires a prescription. This is because melatonin is considered “medical by function” which means that it requires a drug licence.
Stopping the use of melatonin
You should not get any harmful discontinuation or withdrawal effects if you stop taking melatonin. However, you may get your old symptoms back. If you are on a high dose, then the doctor may wish to reduce the dose slowly before stopping it completely.
The Bottom Line. The scientific evidence of the long-term use of melatonin is limited, says Dr. Weiss. The current clinical consensus is that daily melatonin consumption is considered safe.
Furthermore melatonin has been shown to have valuable effects on cardiovascular health, blood pressure, and endothelial function and it might benefit patients with heart failure.
You cannot build up a tolerance to melatonin. This means that the same dosage of melatonin taken every day will not build up in the body, and you won't need a higher dosage over time to experience the same effect.
In several clinical trials, melatonin was found to be well tolerated and not associated with serum enzyme elevations or evidence of liver injury. Despite wide scale use, melatonin has not been convincingly linked to instances of clinically apparent liver injury.
The usual starting dose is one 2mg slow release tablet taken 30 minutes to 1 hour before bedtime. Sometimes the dose may gradually be increased to 2 to 3 tablets before bedtime, depending on how well it works and whether you have any side effects. The maximum dose is 5 tablets (10mg) once daily.
Melatonin promotes calmness and relaxation, helping individuals rest their bodies and minds in order to fall asleep. While most people take melatonin to help with sleep, others may take the supplement for their moods. By nightfall, your body starts to naturally produce melatonin to get you ready to rest.
Long-term use
Melatonin is safe for short-term use, up to 6 months. But some researchers believe that using melatonin for extended periods of time may cause changes to your hormone levels. That being said, there has been no clinical indication of long-term changes to hormone levels so far.
The usual dosage of oral melatonin is 0.1 mg to 5 mg before bedtime (Savage, 2021). In a meta-analysis of clinical studies, the dose of melatonin given to ease pre-surgery anxiety ranged from 3 mg to 14 mg and was taken about one to two hours before surgery (Madsen, 2015).
The possible dangers of using melatonin long-term
As with many hormones in our bodies, having too much or too little melatonin in your system long term can cause health concerns. The problem when taking a melatonin supplement is that since it's not a drug, there's no oversight or regulation by the FDA.
What are the health benefits of taking melatonin? Melatonin supplements may help with certain conditions, such as jet lag, delayed sleep-wake phase disorder, some sleep disorders in children, and anxiety before and after surgery.
The NDPSC considered that insufficient information was available on the safety of melatonin to allow it to remain exempt from scheduling for human therapeutic use and that it should not be available without prescription.
If your levels are too high (for example, if you have recently got off a long-haul flight), you can go out into the light in the morning and do some exercise in the evening. Melatonin pills are available in Australia. Currently, you need a prescription from your doctor for melatonin.
French authorities are urging certain populations to avoid consuming food supplements containing melatonin after incidences of adverse effects were reported to the country's nutrivigilance scheme.