When you buy through our links, we may earn a commission. Products or services may be offered by an affiliated entity. Learn more.
Does Melatonin Expire?
- Melatonin supplements can expire, and their effectiveness may decrease over time as the active ingredients gradually break down.
- Taking expired melatonin is unlikely to be harmful in most cases, but it may not provide the same sleep benefits.
- Proper storage — keeping melatonin in a cool, dry place away from heat, light, and moisture — may help preserve its potency.
- If your melatonin is past its expiration date, shows signs of damage, or has been stored improperly, it’s best to replace it.
Melatonin supplements are widely available over the counter as pills, patches, liquids, and chewable tablets. Like all medications and supplements, though, melatonin can expire. Expiration dates are provided by the manufacturer to indicate when full potency and safety of the medication can no longer be guaranteed, and medications shouldn’t be used past the provided expiration date.
In this article, we’ll explain what happens when melatonin expires, whether it’s safe to take, and how to store it properly.
How Long Does Melatonin Last?
The shelf life of melatonin varies by manufacturer and product type, but most melatonin supplements remain effective for one to two years from the date of manufacture when stored properly. The expiration date printed on the packaging indicates how long the manufacturer can guarantee the supplement’s potency and quality.
How to Store Melatonin
To help melatonin last as long as possible, store it in a cool, dry place away from direct sunlight, heat, and moisture. If your melatonin has passed its expiration date or shows signs of damage, such as changes in color, texture, or odor, it’s best to replace it with a new product.
Can You Take Expired Melatonin?
Considering the long shelf life of many supplements and the relative safety of melatonin, using expired melatonin may not be harmful. Medication and supplement manufacturers choose expiration dates to ensure that you are getting full potency by the printed date. These dates often err on the side of caution. It is possible that your melatonin supplement will maintain its potency past the date printed on the label, though taking expired melatonin is not recommended.
The melatonin supplements you purchase should have an expiration date printed on the label, along with storage instructions. You might notice that melatonin supplements nearing their expiration date do not make you as tired or drowsy. If this is the case, then your melatonin may be losing its potency. It is important to discard and replace melatonin supplements once they have expired.
How Long Does Melatonin Stay in Your System?
Melatonin is fast-acting, with a half-life of 20 to 40 minutes. The half-life of a medication or supplement measures how long it takes for half the dose to be processed and eliminated by the body.
Researchers found that after taking a normal dose of 1 to 5 milligrams, people’s melatonin levels were at their peak within an hour. In that same study, melatonin levels were back to normal after four to eight hours.
Taking an extended release melatonin pill may make you feel more tired when you wake up, especially if you are not able to get a full eight hours of sleep. Extended release pills may also take longer to help you fall asleep. Opting for an immediate release pill or chewable tablet may help you fall asleep faster and wake up feeling more refreshed.
When Should You Take Melatonin?
Melatonin is produced naturally by the pineal gland in the brain and helps the body shift from waking to sleeping. Taking melatonin up to a few hours before bedtime is generally recommended.
You may want to try using melatonin every other night or a few times a week as needed. Any long-term use of melatonin should be discussed with a doctor or medical professional.
How Much Melatonin Should You Take?
Typically, adults can take between 1 to 5 milligrams of melatonin safely. Like any other supplement or drug, it is important to talk to your doctor first. If you choose to try melatonin, start with the lowest dose possible and slightly increase it if needed. In general, it is best to avoid dosages over 10 milligrams , as you may experience unpleasant side effects such as headache and fatigue.
If you are concerned about the potential side effects of melatonin, there are other over-the-counter sleep aids to consider. Diphenhydramine and doxylamine are two popular antihistamines that can also be used to aid sleep. Herbs like valerian have also been shown to help promote sleep.
Finding the sleep aid that works for you may take time, and working with your health care provider can help you find the right fit. Engaging in healthy sleep hygiene practices may also help you get better sleep.
Medical Disclaimer: The content on this page should not be taken as medical advice or used as a recommendation for any specific treatment or medication. Always consult your doctor before taking a new medication or changing your current treatment.
Still have questions? Ask our community!
Join our Sleep Care Community — a trusted hub of sleep health professionals, product specialists, and people just like you. Whether you need expert sleep advice for your insomnia or you’re searching for the perfect mattress, we’ve got you covered. Get personalized guidance from the experts who know sleep best.
Jay Vera Summer is a writer, editor, and wellness coach. She holds a Bachelor's of Science in psychology and Master's degrees in both writing and public policy.
Dr. John DeBanto has been a medical doctor and gastroenterologist for over 20 years. He is board certified in both internal medicine and gastroenterology. He is also a Fellow with the American College of Gastroenterology, serving on the patient care committee. He enjoys educating his patients on nutrition, cancer screening, and weight issues, as he is acutely aware of how obesity can lead to significant morbidity and in particular sleep apnea, fatty liver, cancer, and cardiac issues.
Learn more about our medical advisory boardReferences6 Sources
National Center for Complementary and Integrative Health. (2021). Melatonin: What you need to know.
https://www.nccih.nih.gov/health/melatonin-what-you-need-to-knowTordjman, S., Chokron, S., Delorme, R., Charrier, A., Bellissant, E., Jaafari, N., & Fougerou, C. (2017). Melatonin: Pharmacology, functions and therapeutic benefits. Current Neuropharmacology, 15(3), 434–443.
https://pubmed.ncbi.nlm.nih.gov/28503116/Reiter, R. J., Tan, D. X., & Galano, A. (2014). Melatonin: Exceeding expectations. Physiology (Bethesda, Md.), 29(5), 325–333.
https://pubmed.ncbi.nlm.nih.gov/25180262/Neubauer, D. N. (2022, May 18). Pharmacotherapy for insomnia in adults. In R. Benca & J. G. Elmore (Eds.). UpToDate.
https://www.uptodate.com/contents/pharmacotherapy-for-insomnia-in-adultsMcGrane, I. R., Leung, J. G., St Louis, E. K., & Boeve, B. F. (2015). Melatonin therapy for REM sleep behavior disorder: A critical review of evidence. Sleep Medicine, 16(1), 19–26.
https://pubmed.ncbi.nlm.nih.gov/25454845/Morin, C. M., Koetter, U., Bastien, C., Ware, J. C., & Wooten, V. (2005). Valerian-hops combination and diphenhydramine for treating insomnia: A randomized placebo-controlled clinical trial. Sleep, 28(11), 1465–1471.
https://pubmed.ncbi.nlm.nih.gov/16335333/
