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How Long Does Melatonin Last?

How Long Does Melatonin Last?

Melatonin is a popular sleep supplement, but its use raises the question: how long does melatonin last? 

The answers to this question vary, but since it may be short-acting in some cases, learn how to optimize your melatonin levels in several ways.  

First, though, we will dive into the ins and outs of melatonin. You’ll learn more about the following:

  • What melatonin is and its role in health
  • How nutrition supports melatonin production
  • Benefits of melatonin supplements and how to use them
  • The research on how long melatonin supplements last in the body
  • How to optimize melatonin levels with lifestyle support and supplements

Let’s get started! 

What is Melatonin?

Melatonin is a naturally occurring hormone made primarily in the pineal gland but also in the eyes and gut. (Source 1)

Melatonin production is low during the day and increases in the evening to promote drowsiness and sleep. It is a crucial regulator of the sleep-wake cycle and promotes normal circadian rhythms. It’s essential for overall health. (Source 2)

“Melatonin production is low during the day and increases in the evening to promote drowsiness and sleep. It is a crucial regulator of the sleep-wake cycle and promotes normal circadian rhythms. It’s essential for overall health.”

In addition to its role as the body’s sleep hormone, the effects of melatonin include:

  • Acts as an antioxidant 
  • Regulates the immune system
  • Supports bone health
  • Supports reproduction
  • Supports cardiovascular health
  • Protects the brain
  • Regulates body mass (Source 3

Melatonin production varies among individuals and generally decreases with age, potentially contributing to age-related decline. (Source 1)

Low melatonin levels and disruption of the circadian rhythm are associated with various health conditions, such as:

  • Obesity
  • Insulin resistance
  • Cardiovascular disease
  • Decline in mood, cognition, and memory (Source 1, 4, 5)

Melatonin Production and Dietary Factors

The body converts the amino acid tryptophan into the neurotransmitter serotonin. Serotonin can then convert into melatonin. Therefore, levels of melatonin depend on dietary factors, including tryptophan and micronutrient cofactors: vitamin B6, vitamin B12, and folate. (Source 1)

Melatonin also naturally occurs in some plant foods and can be obtained through the diet. Dietary melatonin is detected in the blood and metabolites in the urine. Natural melatonin-containing foods include: 

  • Tomato
  • Walnuts
  • Whole grains, including rice and barley
  • Strawberries
  • Olive oil
  • Wine
  • Beer
  • Coffee
  • Tart cherry 
  • Pistachio 
  • Nighttime breastmilk produced by breastfeeding moms (Source 1)

Even though beer, wine, and coffee contain melatonin, alcohol and caffeine easily disrupt sleep. 

Melatonin Supplements – Health Benefits

Melatonin is a popular sleep supplement that promotes better sleep. But the benefits don’t end there. Because of the widespread roles of melatonin in the body, people use supplements for:

  • Jet lag
  • Sleep disorders and other sleep issues
  • Internal clock regulation for shift workers
  • Anxiety 
  • Blood pressure regulation
  • Viral infections, including the flu and Covid (Source 3, 6, 7, 8)

Melatonin Supplements – Dosage, Safety, and Side Effects

Melatonin is a dietary supplement regulated by the U.S. Food and Drug Administration (FDA). It’s available over the counter in immediate release or extended release (slow release) forms. 

A typical melatonin dose is between 0.5 and 5 mg taken in the evening. Higher doses don’t necessarily work better. In fact, I recommend using the lowest dose that improves sleep quality without side effects.  

“A typical melatonin dose is between 0.5 and 5 mg taken in the evening. Higher doses don’t necessarily work better. In fact, I recommend using the lowest dose that improves sleep quality without side effects.”

Compared to prescription sleep aids with common side effects, melatonin has relatively few, especially with short-term use

Mild side effects of melatonin may include: 

  • Next day drowsiness or feeling groggy
  • Daytime sleepiness
  • Headache 
  • Dizziness (Source 9)

Please discuss melatonin use with your healthcare team if you take any medication or have a medical condition. Drug interactions with epilepsy and blood thinning medications may be possible. In addition, many low-quality products on the market may not contain what the label claims. (Source 9)

Please note: This article is for informational purposes only and is not medical advice. Please consult with your healthcare provider for personalized guidance regarding your health and supplement use. (move to end?)

How Long Does Melatonin Last?

Once a melatonin supplement enters the bloodstream, it rapidly metabolizes. The half-life in humans is between 10 minutes and 1 hour. The liver deactivates melatonin, and metabolites excrete via the urine. (Source 1)

“Once a melatonin supplement enters the bloodstream, it rapidly metabolizes. The half-life in humans is between 10 minutes and 1 hour.”

One review looked at 22 studies of melatonin supplementation, both melatonin pills and intravenous melatonin. The average time from dose administration to peak blood concentration (Tmax) for oral immediate-release supplements was 50 minutes. The bioavailability of standard oral melatonin is around 15% of the amount of melatonin in the supplement. (Source 10)

In addition, the half-life, or time it takes for half of the supplement to be deactivated, was around 45 minutes. Oral and IV supplements had the same average half-life regardless of the dose of melatonin. (Source 10)

A small study of 27 older adults with low melatonin levels and sleep problems compared a low dose immediate release supplement of 0.4mg and a high dose of 4 mg composed of 75% extended-release melatonin and 25% immediate release. (Source 11)

The results found similar results between the two doses. Tmax was 1.3 hours for the low and 1.5 for the high doses. The half-life was 1.8 hours for the low compared to 1.5 hours for the high dose. In addition, the high dose produced a maintained melatonin level for an average of 10 hours, meaning levels remained elevated beyond a normal sleep window, which may contribute to daytime drowsiness. (Source 11)

While there is some variation between studies, melatonin levels rapidly increase after supplement use. This suggests that the best time to take melatonin is before bed, perhaps 30 to 60 minutes prior. 

Melatonin also rapidly breaks down and is excreted, suggesting that extended release or a combination of immediate and extended release might be helpful for some people. In addition, increasing melatonin absorption and bioavailability via a liposomal delivery system may also be supportive. 

Another option is combining melatonin with other sleep nutrients and herbs, like GABA, magnesium, lavender, rhodiola, or others might be beneficial. Read my Guide to Sleep Supplements here

How To Increase Melatonin Levels and Improve Sleep

Many lifestyle habits and tools support healthy melatonin levels and longer-lasting melatonin effects. Let’s take a look at a few tips to encourage this natural sleep aid

  1. Avoid blue light at night. Natural blue light produced by the sun inhibits melatonin production. This makes sense as we want melatonin levels to be low during the day so we can be active and alert. 

    However, blue light exposure from indoor lighting and screens may have the same effect, which we don’t want in the evening. Avoid bright light in the evening to support the natural rise in melatonin. Use lamps, adjust screen color to an amber tone, or avoid artificial light after dark. 
  1. Practice good sleep hygiene. In addition to adjusting lighting, develop consistent lifestyle habits that promote sleep. Habits to consider are:
    • Setting a regular sleep schedule
    • Exercising during the day instead of the evening
    • Limiting or avoiding caffeine or other stimulants, especially later in the day
    • Creating a relaxing, cool, and dark bedroom
    • Practicing relaxing activities before
  1. Avoid night shifts. If possible, allow yourself to cycle with nature by being awake during the day and sleeping when it’s dark at night. It’s better for your sleep and your health. Otherwise, melatonin supplementation may be useful for supporting daytime sleep when needed. 
  1. Consider liposomal melatonin + GABA for sleep support. CoreMed Science’s Liposomal Sleep Formula contains melatonin, GABA, and glutathione. A standard dose is six pumps, but you can start lower and titrate up until you reach your desired effects. 

The liposomal delivery system ensures that more active ingredients reach your bloodstream. Liposomes mimic the cell membranes of your cells for enhanced bioavailability and effectiveness. 

Melatonin supplements offer a safe and effective solution to various sleep and health issues, often with fewer side effects than pharmaceutical options. Age, blue light, diet, and other factors may depress our natural melatonin production, but I hope is that this article gives you some tools to optimize melatonin levels.

Since the time melatonin lasts in the system may be short, consider adding additional support (like GABA) and adopting sleep hygiene practices. Here’s to a good night’s sleep!


  1. Peuhkuri, K., Sihvola, N., & Korpela, R. (2012). Dietary factors and fluctuating levels of melatonin. Food & nutrition research56, 10.3402/fnr.v56i0.17252. Full text: 
  2. Hardeland, R., Pandi-Perumal, S. R., & Cardinali, D. P. (2006). Melatonin. The international journal of biochemistry & cell biology38(3), 313–316. Abstract: 
  3. Tordjman, S., Chokron, S., Delorme, R., Charrier, A., Bellissant, E., Jaafari, N., & Fougerou, C. (2017). Melatonin: Pharmacology, Functions and Therapeutic Benefits. Current neuropharmacology15(3), 434–443. Full text: 
  4. Reutrakul, S., & Van Cauter, E. (2018). Sleep influences on obesity, insulin resistance, and risk of type 2 diabetes. Metabolism: clinical and experimental84, 56–66. Abstract: 
  5. Durmer, J. S., & Dinges, D. F. (2005). Neurocognitive consequences of sleep deprivation. Seminars in neurology25(1), 117–129. Abstract: 
  6. Anderson, G., & Reiter, R. J. (2020). Melatonin: Roles in influenza, Covid-19, and other viral infections. Reviews in medical virology30(3), e2109. Full text: 
  7. Razavi, P., Devore, E. E., Bajaj, A., Lockley, S. W., Figueiro, M. G., Ricchiuti, V., Gauderman, W. J., Hankinson, S. E., Willett, W. C., & Schernhammer, E. S. (2019). Shift Work, Chronotype, and Melatonin Rhythm in Nurses. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology28(7), 1177–1186. Full text: 
  8. Bazyar, H., Zare Javid, A., Bavi Behbahani, H., Moradi, F., Moradi Poode, B., & Amiri, P. (2021). Consumption of melatonin supplement improves cardiovascular disease risk factors and anthropometric indices in type 2 diabetes mellitus patients: a double-blind, randomized, placebo-controlled trial. Trials22(1), 231. Full text: 
  9. NIH National Center for Complementary and Integraive Health. (2022). Melationin: What You Need to Know. Accessed 10/13/22: 
  10. Harpsøe, N. G., Andersen, L. P., Gögenur, I., & Rosenberg, J. (2015). Clinical pharmacokinetics of melatonin: a systematic review. European journal of clinical pharmacology71(8), 901–909. Abstract: 
  11. Gooneratne, N. S., Edwards, A. Y., Zhou, C., Cuellar, N., Grandner, M. A., & Barrett, J. S. (2012). Melatonin pharmacokinetics following two different oral surge-sustained release doses in older adults. Journal of pineal research52(4), 437–445. Full text: 
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