Don't take ZzzQuil every night. Talk with your doctor if you have questions about how long you can take ZzzQuil and at what dosage. In general, taking this medication only from time to time should keep side effects to a minimum. Talk to your doctor if you think this medication isn't helping you sleep.

ZzzQuil liquid capsules help you fall asleep in as little as 20 minutes. ZzzQuil LiquiCaps contain a non-habit-forming ingredient, Diphenhydramine HCI, that helps you get the sleep you need. Each dose (two LiquiCaps) contains 50mg.

Our original ZzzQuil formula has the active ingredient Diphenhydramine HCL, an antihistamine, while our PURE Zzzs formula has the hormone melatonin. While both lines help you fall asleep, we've provided this drug free alternative to our proven sleep aids line so that you can choose the product that works best for you.

It is important to note, the affected Vicks Children's Botanical and PURE Zzzs liquid melatonin products are safe and meet P&G's quality standards.

It is typically safe for adults to take melatonin every night for short periods of time.

Diphenhydramine also causes drowsiness, and can be used by adults and children 12 years of age and older who occasionally have trouble sleeping (insomnia). The effects of diphenhydramine can last for up to 6 hours. If you have trouble sleeping, do not take this medication for more than a few nights in a row.

Anxiolytics/sedatives/hypnotics (applies to ZzzQuil) depression. Major Potential Hazard, Moderate plausibility.

“If melatonin for sleep isn't helping after a week or two, stop using it,” says Buenaver. “And if your sleep problems continue, talk with your health care provider. If melatonin does seem to help, it's safe for most people to take nightly for one to two months. “After that, stop and see how your sleep is,” he suggests.

Diphenhydramine also causes drowsiness, and can be used by adults and children 12 years of age and older who occasionally have trouble sleeping (insomnia). The effects of diphenhydramine can last for up to 6 hours. If you have trouble sleeping, do not take this medication for more than a few nights in a row.

To summarize, melatonin is a safer choice to treat insomnia than Zzzquil or Tylenol PM. If your insomnia is more moderate, you may want to try Zzzquil, and if you're also dealing with acute pain or fever, then you may want to try Tylenol PM, but be careful to follow the directions and avoid overusing these drugs.

This drug can often cause excitement in young children instead of drowsiness. Older adults may be more sensitive to the side effects of this drug, especially drowsiness, dizziness, confusion, constipation, or trouble urinating.

It's readily available, and it's supposed to help you sleep . . . right? Sleep deprivation can make this logic seem sound, but experts say taking melatonin in the middle of the night can actually make your sleep schedule even worse.