What You Should Know Before Taking Cold Medicine To Help You Sleep

Sleepless nights can totally destroy your productivity for the day ― and even weeks ― ahead. Research shows that lack of a good night’s rest is associated with brain fog and irritability, and over time, sleeplessness is linked with an increased risk for heart disease and diabetes, a decreased sex drive and a weakened immune system. 

So it’s no wonder people turn to all different kinds of sleep aids when they’ve spent a night or two tossing and turning. And since sleeplessness is usually something we deal with at night, often we look for something already in the medicine cabinet to keep our eyelids closed.

But not all sleep aids are created equal ― and one popular drug many people turn to for shuteye, Nyquil (or similar over-the-counter cold medications), may not be the best solution.

Cold medications can help with sleeplessness because the drugs usually contain doxylamine or diphenhydramine, two sedating antihistamines that can quickly cause drowsiness to set in. 

According to Susheel Patil, clinical director at Johns Hopkins Sleep Medicine, in the absence of a cold, “it may be all right for a few days to use OTC cold medications that contain antihistamines to help with insomnia symptoms.” But beyond that, you can experience some pretty rough consequences if you’re not careful.

More Than A Sleep Aid

Relying on cold medicine to get rest without the presence of a cold isn’t the best move. If you’re in a desperate situation, Patil said it’s better to use an OTC medication that only contains an antihistamine, rather than the host of other ingredients cold medications contain.  

“OTC cold medications typically contain several medications, including a pain reliever, a cough suppressant and an antihistamine,” Patil explained. “Since these OTCs have many medications in them, using them for sleep may subject you to side effects from the other medications contained within it. If medications are to be used to help with sleep, it’s best to use that medication alone.” 

Patil added that it’s crucial to first read the labels of these medications, understanding what each active ingredient is meant to treat. Additionally, it’s important to note the antihistamines, even on their own, can have some not-so-great side effects. 

“These medications have an elimination half-life of 10 to 12 hours, which means they are often circulating [in] your blood after you are waking up,” Patil said, adding that this can lead to grogginess, sleep inertia, headaches or not feeling clear-headed in the morning. Some people also report “palpitations or a fast heart rate. In older individuals, there can be concerns about constipation and urinary retention,” he said. 

Even more, “the medication can impair coordination, increasing the risk for a nighttime fall,” added Nathaniel Watson, co-director of the University of Washington Medicine Sleep Center and SleepScore Labs scientific advisory board member. Medications like Nyquil can also trigger arrhythmias and seizures, Watson explained. For these reasons, physicians generally do not recommend Nyquil as a sleep aid.

Not everyone will drift off to la-la land with aid from a cold medicine, either. And your quality of sleep using it (or even something like Benadryl) may not even be that great.

“There is wide variation in the sleepiness effect of Nyquil,” Watson said. “This is likely related to genetic factors that influence how much of the drug is absorbed and how effective it is blocking histamine functionality in the brain.” 

And some may be in for a dreadful surprise: “A small number of patients will feel more activated after taking this medication,” Patil said. This phenomenon, which can worsen a person’s sleeplessness, is often referred to as a paradoxical stimulation of the central nervous system.

Sleep Aids Won’t Dissolve Your Sleep Issues

So, what about using Zzzquil — basically, Nyquil’s cousin ― to help you sleep? This product contains an antihistamine without the added cough suppressant and pain reliever of the cold medicine. Patil said this could be a better solution than cold medicine, but “if you find yourself having to use this medication for more than two weeks, you should talk with your doctor to better understand why you are having insomnia symptoms or unrefreshing sleep.” 

Even supplements like melatonin aren’t necessarily great for you. These aids are not meant to be solutions to sleep, but short-term helpers. And if you’re finding that side effects like grogginess have a real effect on your day, you might want to seek out other alternatives. 

“Sleep issues can signify a number of sleep disorders, such as obstructive sleep apnea, restless legs syndrome, insomnia or narcolepsy,” Watson said, noting that sleep aids like Nyquil or others are “ not an appropriate therapy for these diseases,” because they don’t address “the root cause of the problem.” 

There are many natural sleep remedies that have been found to work for people who have trouble sleeping if you want to give something other than medicine a try. Other than that, speaking directly with your doctor about your restless nights is always a smart place to start.  

“Living With” is a guide to navigating conditions that affect your mind and body. Each month in 2019, HuffPost Life will tackle very real issues people live with by offering different stories, advice and ways to connect with others who understand what it’s like. In July, we’re covering sleep and sleep disorders. Got an experience you’d like to share? Email wellness@huffpost.com.