How long does melatonin last?

July 05, 2020.
Many women in perimenopause struggle to fall asleep. In fact, insomnia is one of the 34 symptoms of perimenopause. Women turn to a variety of lifestyle changes and sleep aids to try to get a good night’s rest. Indeed, we all know that poor sleep quality (and quantity) affects our ability to function in our day-to-day lives.
Furthermore, poor sleep can aggravate other perimenopause symptoms, including brain fog, irritability, and depression. To combat menopause insomnia, many women first try melatonin because it is the hormone that regulates our sleep. Read on to learn how melatonin works and how long does melatonin last in your body.

What is melatonin?

Melatonin is a hormone that occurs naturally in our body that helps regulate sleep. It is released by the pineal gland in your brain when you are exposed to darkness. Melatonin levels are highest when it becomes dark at night and fall in the morning when it becomes light. Low levels help you stay awake throughout the day.
Some people do not produce enough melatonin, or they have difficulty falling asleep naturally due to certain causes, including:
  • Jet lag
  • Menopause insomnia
  • Blindness
  • Working night shifts
  • Dementia and Alzheimers
  • Chronic illness
  • Side effects of some medications
We do not know too much about the long-term side effects of melatonin, as it is not widely studied. In most people, there are few side effects to using melatonin other than drowsiness, which is more common when you take a larger dose. However, if you have another health condition or you take medication, make sure to touch base with your doctor to verify melatonin is safe for you.
Melatonin can be purchased over-the-counter in the form of gummies or pills. You may have an option to buy regular melatonin or extended-release melatonin. Sometimes, it is also an active ingredient in other dietary supplements, such as those designed for women in menopause.

How long does it last in your system?

It is essential to know how long medications stay in your body, especially if they have effects that may compromise your ability to drive, operate equipment, or make important decisions. Because melatonin helps you relax and causes drowsiness, you should only take this supplement if you can sleep for a specific length of time.
All drugs have a half-life. A half-life is the amount of time it takes for half of the drug to clear out of your system. Melatonin is quickly absorbed in the body and begins to work right away, especially if you use regularly. Regular melatonin should be taken within one hour before you intend to fall asleep. However, each person may respond differently to when it begins to work, so you may need to play around with timing.
Typically, the half-life of melatonin is just short of one hour. Therefore, if you take 1 mg of melatonin, you will only have 0.5 mg left in your system after one hour. In the following hour, you will have 0.25 mg left. And so on. Melatonin lasts in your body for about 5 hours, so you will want to make sure you do not need to operate a vehicle or heavy equipment for at least 5 hours after taking melatonin.
If you are asking yourself, how long does 5mg of melatonin last in my system, the answer is the same if you are using regular melatonin → about 5 hours. If you use extended-release melatonin, the effects may last longer and be different in strength compared to regular melatonin.

So, if you are just getting started with melatonin, try these tips:

  • Make sure you have made lifestyle changes to improve your sleep, such as turning down the thermometer to prevent night sweats.
  • Start with the lowest dose and work up as needed. You will likely start at 1 mg.
  • Take your melatonin dose 30 minutes before ideal bedtime.
  • Give yourself ample time to rest in case it really works for you (as in you get more than 5 hours of sleep).
  • Be open-minded. If it works, great! If it doesn’t, touch base with our doctor to see what other sleep aids are available to you.Those struggling to manage other menopause symptoms alongside insomnia may benefit from hormonal options such as hormone-replacement therapy to help balance your hormones.
Disclaimer: This is not medical advice, does not take the place of medical advice from your physician, and is not intended to treat or cure any disease. Patients should see a qualified medical provider for assessment and treatment. 

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Julia Walker
perry expert Julia (RN, BSN, BA) is a registered nurse based in Colorado. Julia's nursing background in women’s health has ranged from neonatal and postpartum care to labor and delivery, to outpatient gynecological medicine for both adolescent and adult populations. She specializes in helping women optimize their health during perimenopause and beyond.

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