A popular sleep aid, melatonin's job is to help regulate the circadian rhythm and keep the sleep-wake cycle on track. But if you frequently take melatonin or have recently tried it to get on a sleep schedule, you might find it's not as effective as it should be. Here's why and what to do about it.

mbg's director of scientific affairs and nutritional supplement expert Ashley Jordan Ferira, Ph.D., RDN, offers up this additional insight: "Taking melatonin, particularly at higher doses, can be linked to undesirable desensitizing phenomena, such as nightmares, grogginess, and headaches." She goes on to say that, "For many people, they require incrementally more melatonin over time to achieve the same effect, which is a futile cycle I recommend folks avoid."

Time for bed. You've popped a melatonin supplement, tucked yourself in, and wait to drift off to dreamland. And wait. And wait. There are a few reasons you might find yourself counting sheep. Some of the most common ones include:

Dimitriu explains that if you're someone who does shift work or works nights, like a nurse, it might be extra difficult to regulate your circadian rhythm.

"Stress, in general, can suppress the hypothalamic sleep control center," says Teitelbaum. "If adrenal stress hormones are too high at bedtime, it will keep your mind racing, making it difficult to sleep. Similarly, if cortisol levels drop in the middle of the night, your blood sugar will fall with it. This causes those middle-of-the-night wake-ups."

If you regularly take melatonin, particularly at doses higher than 1 milligram, you might find that its benefits start to wear off over time. This desensitizing effect is why functional medicine doctor Frank Lipman, M.D., recommends taking it for a short period, just to get your body to fall asleep at a new time (say, when you're traveling across time zones or adjusting to a new work schedule) instead of every night.

Research has found that melatonin levels decline with age4. Those who are older and take melatonin to balance their circadian rhythm may have more success with it5, one 2005 study published in the Journal of General Internal Medicine found.

Teitelbaum adds that by choosing a sustained-release melatonin formula, your dose will be delivered at a programmed rate over a period of time. This may help prevent you from waking up in the middle of the night.

If you're regularly struggling to fall asleep and sleep through the night, Dimitriu says it's smart to consult a health care provider about the problem.

If you're ready to start snoozing and your melatonin isn't as effective as you'd like it to be, there are a few solutions that may help promote sleep:

"Sleep, as well as natural melatonin production, does well with rhythm," says Dimitriu. "Regular bed and wake times go a long way and often can achieve more than sleep aids can." Here's a primer on how to get into the groove of a regular bedtime.

"Particularly if you are someone who wakes up at 2 a.m. or 4 a.m., a 1- to 2-ounce protein snack (like a hard-boiled egg) at bedtime for a few nights can tell you if blood sugar is the culprit behind your disrupted sleep," says Teitelbaum. Hungry for some ideas? Here are sleep experts' go-to nighttime nibbles.

Aim to turn off electronics, dim the lights, and use softer, more yellow bulbs at least an hour before bedtime to keep your circadian rhythm in check.

Ferira divulges that, "melatonin is, in fact, not my go-to sleep-centric supplement for clients. It's more of a last resort or personalized approach for certain individuals. For starters, melatonin is a hormone, so tread lightly. Secondly, there are loads of ways to optimize sleep hygiene that naturally support circadian rhythm syncing. Lastly, I strongly prefer nutrients, botanicals, and nonhormonal bioactives when it comes to supplements, for sleep or otherwise."*

If a good night's sleep has been elusive for you, mention it to your health care provider and look into nonhormonal sleep aids, particularly safe and effective minerals, herbs, and bioactives like magnesium, jujube, and PharmaGABA®.*