If you’ve found yourself struggling to fall asleep over the last few days, then you’re probably getting really frustrated. There’s nothing quite like the sensation of struggling to get through the day because you’re so tired, only to find that once you finally climb under our covers and get your head on the pillow, you’re just as wide awake as you’ve been the last few nights. It’s natural to look for help, and the local pharmacy definitely offers plenty of sleep aids, but it is important that you understand what you’re taking before you go that route, so let’s take a closer look. Reading the label on just about any over-the-counter sleep aid reveals that its primary active ingredient is diphenhydramine. If that sounds familiar to you, you may want to take a stroll over to the allergy section and take a peek at the Benadryl and other meds for sniffles and scratchy throats, because most of them have the exact same active ingredient. According to Shalini Paruthi, M.D., a fellow of the American Academy of Sleep Medicine and the director of the Pediatric Sleep and Research Center at Cardinal Glennon Children’s Medical Center, the reason that they’re the same is that antihistamines, which clear us of allergy symptoms, also make us sleepy. “We do know that antihistamines can certainly make people feel sleepy, and so we do find diphenhydramine in a number of over-the-counter medications that advertise as helpful for people trying to fall asleep at night,” she says. “But it’s important to know that when we use something like diphenhydramine to help us sleep at night, we’re actually using it for its side effect – not its treatment, which is to fight allergies.” Allergy medications and over-the-counter sleep aids have not been the subject of much research into the impact of long-term use, and this is likely because people only use it for short periods of time. Those who suffer from insomnia will either find the relief that they need or look for something else. Dr. Paruthi says that most doctors and sleep experts’ only concerns about their use is in terms of how they may interact with other medications. Speaking generally, people who are healthy will be fine taking them for a few days, though there are concerns about the common side effect of feeling drowsy beyond the period that was hoped or intended. One advantage that over-the-counter sleep aids offer is that many of them also include synthetic melatonin, the hormone that tells our bodies when it is time to go to sleep. Some people have found success with sticking to melatonin alone, or other herbal remedies. Dr. Paruthi suggests that before turning to medications of any kind, people having trouble getting to sleep should take a careful look at their nighttime habits to ensure that they are blocking out unwanted noise and light, getting exercise during the day, and staying away from electronic devices, caffeine and alcohol, all of which can interfere with the ability to sleep.