But remember, melatonin is a hormone, not a sleep medication, therefore it does not induce sleep. In fact, taking a second dose late into the night may promote undesirable side effects such as extreme drowsiness the next day.
It may be tempting to take this when we wake up and can't fall back to sleep, but this timing is ineffective because our naturally occurring melatonin hormone levels are at peak levels already, says Naima Covassin, PhD, a sleep researcher at the Mayo Clinic in Rochester, Minnesota.
OTC melatonin can stay in the body for 4–10 hours, depending on the dose and formulation. People should avoid taking melatonin at or after their intended bedtime. Doing so can shift their sleep-wake cycle and lead to daytime sleepiness.
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.
Taking too much melatonin can actually cause rebound insomnia —either rendering the supplement ineffective or worse, exacerbating your already sleepless nights further. You only need tiny doses of melatonin to support your natural sleep cycle.
While melatonin is generally considered safe, it is possible to take too much. There is no official recommended melatonin dosage, and people can have different sensitivities to melatonin, so finding an appropriate dose can be challenging.
How Long Does Melatonin Stay in Your System? The half-life of melatonin is between 20 and 50 minutes, meaning half of the initial dosage in the body is eliminated after that amount of time. In total, melatonin stays in your system for about four to five hours.
There may also be underlying health conditions or medications that interfere with the impact of melatonin. Poor sleep habits, irregular sleep schedules, late-night eating, caffeine, not following the suggested use, and lifestyle habits like late-night screen time may also cause melatonin supplementation not to work.
Taking melatonin as a sleep aid
This method is meant to help you fall asleep faster in a very short amount of time. Dr. Goldman suggests starting with 1 mg, and then increasing that amount by 1 mg (not to exceed 10 mg) every week until you've reduced the amount of time it takes you to fall asleep.
The best time to take melatonin is when you can sleep for at least six hours. With less than six hours of sleep, the additional melatonin may leave you groggier than usual and tired the next day. Therefore, you do not want to take melatonin in the morning or when you won't be able to sleep long enough.
Keep in mind that melatonin as it occurs naturally in the body doesn't have much of a daytime presence, so if you take melatonin too close to morning (such as if you wake up at 4am and erroneously take some to get back to sleep), or during the day, you can set yourself up for not just being drowsy and groggy, but ...
Probably because you are getting all the dose at once; you could try a sustained release and see if that helps. The best way for you to get melatonin is allowing your body to make it.
Excessive consumption can cause lethargy, disorientation, and low blood pressure. It is important for people using melatonin to be mindful of side effects and always begin with the lowest dose possible.
Care needs to be taken with the timing of melatonin supplements—too early or too late and it can just exacerbate the problem. Working with a specialist in behavioral sleep medicine generally is required. If you've considered treatment for insomnia or another sleep disorder, now might be a good time to look into it.
Practice good sleep hygiene.
"Sleep, as well as natural melatonin production, does well with rhythm," says Dimitriu. "Regular bed and wake times go a long way and often can achieve more than sleep aids can." Here's a primer on how to get into the groove of a regular bedtime.
Regardless of whether it truly helps with sleep or not, Dr. Ramkissoon doesn't recommend taking melatonin long-term.
A 2017 study indicated melatonin as an effective and safe option for treating people with anxiety following acute coronary syndrome (ACS). A 2018 study found that the administration of melatonin was more effective in improving anxiety and sleeping patterns than the drug oxazepam in people undergoing heart surgery.
It's important to note that there isn't a “safe” dosage of melatonin. Generally, an adult dose is thought to be between 1 and 10 mg. Doses near the 30 mg mark are usually considered to be harmful. However, people's sensitivity to it can vary, making some more prone to side effects at lower doses than others.
Taking more than 10mg of melatonin is not recommended by healthcare professionals, and could lead to melatonin overdose, which comes with a host of potential negative side effects. These more serious side effects may include: Excessive sleepiness. Vomiting.
A typical melatonin dose is around 0.1 to 10 milligrams, which is already substantially higher than what your body produces—between 10 to 80 micrograms a night. While it would be extremely rare to overdose on melatonin, taking too much can cause headaches, vomiting, and even changes in blood pressure.