Melatonin is becoming an increasingly popular supplement nowadays. Research has proven it to be very effective in regulating our circadian rhythm, helping us to achieve better quality sleep - something we all need when living in an artificially lit world!

Melatonin is also absorbed and excreted fairly quickly. The half-life (the time it takes to eliminate half the dose of a drug) of melatonin is about 30 to 40 minutes, and it takes 4 to 5 half-lives to eliminate the supplement. This means melatonin can stay in our system for around 4 to 5 hours.1

Let’s explore melatonin, how it works, and how best to take it to optimize our sleeping patterns.

What is Melatonin?

You know that sleepy feeling you get when you climb into bed every evening? That’s caused by your melatonin levels rising, signalling to your body that it’s time for sleep.

Melatonin is a naturally occurring hormone released by the pineal gland located in our brain. It helps us regulate our sleep-wake cycle, otherwise known as our circadian rhythm.

Melatonin is regulated by light, so when we are exposed to light in the daytime, our melatonin is suppressed, so we feel active and alert.

However, in the evening, as the lights dim, our melatonin increases, which is what causes us to feel sleepy.

These days we typically reside in environments that don’t cater well for our natural melatonin production. Artificial light, work stress, sleep disorders, and general life can often get in the way of achieving a natural, good quality sleep.

This is why supplementation is recommended, and is particularly useful for those who may suffer with circadian rhythm disorders such as:

  • Frequent travellers (in relation to jet lag)
  • Shift workers

Though melatonin doesn’t just help us sleep better!

Other benefits to melatonin include:

  • Neuroprotective effects, as it is a powerful antioxidant
  • Anti-cancer properties
  • Eye health
  • Reducing symptoms of tinnitus
  • Improving mood2

Best Time to Take Melatonin

The best time to take melatonin would depend on the supplement, especially as some supplements are formulated to extend the release to mimic the effects of natural melatonin production.

However, it’s generally recommended to take melatonin 30-60 minutes prior to your intended sleep.3

We recommend taking Performance Lab Sleep 30-minutes before bedtime for the best results!

Melatonin: Dosage and Side Effects

It’s recommended to start with a low dose to determine your tolerance, around 0.5mg is often reported as a dose to begin with. Though, up to 3-5mg is thought to be an effective dose with no adverse effects the following day.

Taking more will not necessarily lead to better sleep, as you could put yourself at risk of a melatonin overdose which can have negative side effects, such as daytime drowsiness, headaches, and nausea.

How Long Does Melatonin Remain in Our System?

Typically, melatonin remains in our system for around 4 to 5 hours. This is why it’s not recommended to drive or operate heavy machinery within 5 hours of taking it, nor taking it during the daytime.

However, the total time it takes for any supplement or medication to clear will differ from person to person, melatonin included. This is the reason it’s important to determine a dose that works for you, and experiment with your ideal timing.

The following factors could affect how long melatonin stays in your system4:

  • Age
  • Caffeine intake
  • Body weight
  • Other medications
  • Whether you smoke tobacco
  • How often you take melatonin
  • Overall health status


Melatonin is a naturally occurring hormone that helps us regulate our sleep-wake cycle, or our circadian rhythm. Supplementation is recommended, particularly for those who are frequent travellers or shift workers.

It’s generally recommended to take melatonin 30-60 minutes before bedtime, starting with a low dose to determine your tolerance. Doses of up to 3-5mg are shown to be effective with minimal side effects.

Melatonin typically stays in our system for around 4-5 hours, though this depends on several factors such as weight, age, and health status. Be careful not to drive or use heavy machinery within 5 hours of taking it.

More melatonin does not equal better results, so avoid overdosing or supplementing throughout the daytime, which could further hinder your sleep schedule!


  1. Hyde, M. (2021) How Long Does Melatonin Last in Your System? Early Bird by AmeriSleep.
  2. K. Patel. Melatonin. 2021