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Does NyQuil Make You Sleepy?

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NyQuil is a common over-the-counter medication that people take at night to relieve symptoms of a cold or the flu. However, one of the possible symptoms of NyQuil is drowsiness1. As a result, some people may wonder if it’s safe to use as a general sleep aid. 

In this article, we’ll delve into everything you need to know about NyQuil, including why it makes some people sleepy, whether or not it should be used as a sleep aid, how often you should take it, and more. After reading, you should have a better sense of what NyQuil is and how it can be used properly.

What Is NyQuil?

NyQuil is the brand name of a nonprescription medication manufactured by Vicks. You can purchase NyQuil over the counter at local stores and pharmacies, and it should be used to manage cold and flu symptoms like sneezing, sore throat, headaches, minor aches and pains, fever, runny nose, and cough.1

NyQuil Ingredients

The three active ingredients in NyQuil are doxylamine succinate, dextromethorphan, and acetaminophen.1 

How Long Does NyQuil Last?

If you are over the age of 12, you can take NyQuil every six hours, and you should take no more than four doses in 24 hours.1 

Why Does NyQuil Make Some People Sleepy?

NyQuil makes some people sleepy because it contains doxylamine succinate, which, as mentioned, is sometimes used as a short-term sleep aid for insomnia. Doxylamine succinate can make you feel drowsy, which is how it can help you to fall asleep more easily.2

How Long Does It Take for NyQuil to Make You Sleepy?

NyQuil should take around 30 minutes to start working, according to Vicks.1 However, NyQuil is not an official sleep aid, so it’s not guaranteed that you will start feeling drowsy within 30 minutes of taking it.

Should NyQuil Be Taken as a Sleep Aid?

Although NyQuil contains ingredients that induce drowsiness, it should not be taken primarily as a sleep aid as misuse of NyQuil has the potential to lead to addiction or dependence5 on the medication. You should only be taking NyQuil short-term for cold or flu-like symptoms. 

NyQuil Side Effects

According to Vicks, NyQuil can cause drowsiness, and the manufacturer warns that people should not take it with alcohol and to exercise caution when operating a vehicle or heavy machinery.1

If you are worried about the side effects of NyQuil, we urge you to contact your healthcare provider.

Who Should Avoid Taking NyQuil?

If you are pregnant or breastfeeding, it’s recommended that you speak with your primary care provider to determine if it’s safe for you to take. Additionally, children under 12 years old should not take NyQuil.1

Vicks also warns that because NyQuil contains acetaminophen, it may cause severe liver damage in certain cases. Those cases include taking more than four doses in 24 hours, taking it with other medications containing acetaminophen, and having three or more alcoholic beverages while taking it.1 For this reason, it’s especially important to check with your healthcare provider about taking NyQuil if you already have liver issues. 

How to Sleep Better Without NyQuil

Instead of using NyQuil as a regular sleep aid, we recommend implementing good sleep hygiene habits that should help you sleep more peacefully. 

  • Make your bedroom ideal for sleep  – The ideal sleep environment is cool, dark, and quiet, so you want to make your bedroom like this as best you can. It’s also helpful to invest in the right mattress for your sleep position and body type to help you be even more comfortable.
  • Form a consistent nighttime routine – If you do the same activities before you go to sleep each night, your body will begin to associate those activities with bedtime, which will hopefully help you fall asleep more easily. A nightly routine might include reading, doing yoga or meditation, or taking a warm shower
  • Avoid screens before bedtime – You should avoid blue light devices like TVs, cellphones, and laptops before you go to bed, ideally for up to an hour. The reason for this is that blue light6 can leave you more alert because it tricks the body into thinking it’s daytime.
  • Avoid caffeine before bedtime – Drinking caffeine at night seems like a no-brainer, but some people may think having it in the late afternoon is still okay. However, caffeine can stay in your system for as long as six hours7, so you’ll want to plan your last cup of coffee accordingly. 
  • Take a melatonin supplement – Sometimes your body can’t produce enough melatonin naturally to help you fall asleep, so you may want to try taking a melatonin supplement. Melatonin supplements can help regulate8 your sleep-wake cycle, which, in turn, could help you sleep better. That said, we advise consulting your healthcare provider before taking any new supplements. Explore our picks for the best melatonin supplements for sleep.

Frequently Asked Questions

How many nights in a row can you take NyQuil?

You should not take NyQuil for more than seven nights9 in a row. If you still feel sick after a week of taking NyQuil, contact your healthcare provider.

How long does it take NyQuil to wear off?

It takes NyQuil around six hours to wear off. You can take another dose of NyQuil after those six hours, and you should take no more than four doses in 24 hours.1

What’s the difference between NyQuil and ZzzQuil?

NyQuil is meant to relieve cold and flu symptoms and is not meant to be used as a regular sleep aid, whereas ZzzQuil10 is a non-habit-forming sleep aid. ZzzQuil’s main active ingredient is an antihistamine called diphenhydramine HCl10, which induces drowsiness, helping you fall asleep more easily. Either way, neither of these products should be used long-term as a sleep aid.

Emma Cronan

Emma Cronan


About Author

Emma is an Editorial Intern for Sleep Advisor. She collaborates with the editor and staff writers to come up with article ideas, create article outlines, and write for the website.

Combination Sleeper


  1. “NyQuil”. Vicks. Webpage accessed January 9, 2024.
  2. “Doxylamine”. Medline Plus. Last modified July 15, 2018.
  3. “Dextromethorphan”. Medline Plus. Last modified January 15, 2022.
  4. “Acetaminophen”. U.S. Food and Drug Administration. Last modified June 9, 2022.
  5. “NyQuil Addiction And Abuse”. Addiction Center. Last modified October 26, 2023. 
  6. Wahl, Siegfried., et al. “The inner clock—Blue light sets the human rhythm”. Journal of Biophotonics. 2019.
  7. Drake PhD, Christopher. “Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed”. Journal of Clinical Sleep Medicine. 2013. 
  8. Bauer MD, Brent A. “Is melatonin a helpful sleep aid — and what should I know about melatonin side effects?”. Mayo Clinic. 2022. 
  9. “NyQuil Severe Cold and Flu”. Webpage accessed January 17, 2024.
  10. “ZzzQuil LiquiCaps”. ZzzQuil. Webpage accessed January 17, 2024.
  11. “VICKS ZZZQUIL FAQ”. Vicks. Webpage accessed January 17, 2024.