“‘Grogginess’ is sometimes reported after melatonin use, along with headache, dizziness, upset stomach, and even mood alterations such as temporarily feeling down or feeling more anxious,” notes Ellen Wermter, FNP-BC, a family nurse practitioner and spokesperson for the Better Sleep Council. Vivid dreams, increased daytime sleepiness, and even hormone disruption1 are also possible. However, if you still have excess melatonin in your system by the time you wake up, you’re likely to feel a little groggy and sleepy. This is bound to happen after you take melatonin doses that are too high, explains leading sleep specialist Michael J. Breus, Ph.D. While melatonin is generally recognized as safe2 up to 10 milligrams, Breus says that more is not better when it comes to supplementing with the hormone, unless otherwise instructed by a doctor. Even doses in the 1- to 5-milligram range can lead to blood serum levels 10 to 100 times higher3 than what our body makes naturally, Wermter points out. So taking around 0.5 milligrams of melatonin should still be enough to help regulate the circadian rhythm—without causing as much grogginess or morning fatigue. Laura Erlich, LAc, FABORM, a fertility and obstetric specialist and founder of Mother Nurture Wellness, adds that taking melatonin too close to your desired bedtime can also set you up for fogginess. Consuming supplemental melatonin at least an hour before bed (or 12 hours after you wake up) should minimize the chance of it still being in your system by your morning alarm, says Wermter. Finally, Christina Graham, R.N., a registered nurse and Noom coach, notes that genetics can also affect how quickly you process melatonin and therefore how your body reacts to it. Revée Barbour, N.D., M.S., naturopathic doctor, and owner of Dr. Ray, N.D., in Sacramento, Calif., echoes that if your body is already making enough melatonin of its own, taking a supplement won’t necessarily support your sleep and could do more harm than good. So while it can be a helpful tool to pack on a long-haul flight, melatonin should not be taken as a nightly sleep aid—especially not in higher doses. Instead, you’re better off supporting your body’s natural melatonin production by waking up at the same time every day and getting outside early, avoiding heavy meals too close to bedtime, and staying off screens at night. And if you are looking for a supplement to add to your already healthy sleep routine, look for a nonhormonal option like mbg’s sleep support+, which reviewers say has dramatically deepened their rest sans the side effects of melatonin.* Emma received her B.A. in Environmental Science & Policy with a specialty in environmental communications from Duke University. In addition to penning over 1,000 mbg articles on topics from the water crisis in California to the rise of urban beekeeping, her work has appeared on Grist, Bloomberg News, Bustle, and Forbes. She’s spoken about the intersection of self-care and sustainability on podcasts and live events alongside environmental thought leaders like Marci Zaroff, Gay Browne, and Summer Rayne Oakes.
