ZzzQuil Review: An Extremely Effective Sleep Aid

Last updated: January 23, 2017
ZZZQuil Review

We've all been there.  You can’t sleep, but you’re not sick. You reach for that bottle of NyQuil in your medicine chest. Is it bad to take NyQuil to fall asleep when you’re not even sick? Now, you don’t have to.  Vicks has released a sleep aid called ZzzQuil knowing that people were taking NyQuil to sleep when they weren’t sick. Now you can get some sleep without the possible side effects that come with taking a cold medicine when you aren’t actually sick.  Does it work? In this ZzzQuil review, I will discuss its effectiveness and the possible side effects of this over the counter sleep aid.


Review of: ZzzQuil

Use: Sleep Aid


Excellent, low-cost sleep aid.


Low cost per use.

Ease of Use

Very easy to use. Ingest 20 minutes before bed.

We Like

  • Inexpensive - you're not out much to give it a try.
  • It's fast acting.  No need to wait hours for it to kick in.
  • Proven effective ingredients.

We Don't Like

  • Like most medicine, it does carry some possible side effects.
  • Liquid form contains alcohol.  Liquicaps do not.

Summary: ZzzQuil is a very effective sleep aid with few side effects.  It is very easy to use as it comes in pill or liquid form and just needs to be taken 20 minutes prior to going to bed.

What is ZzzQuil?

Since Vicks is a household name and NyQuil is known to help you sleep, the company took advantage of their reputation and released this non-habit forming and over the counter sleep aid.

It is available in liquid capsule, otherwise known as liquicaps, or liquid form.

Those looking for the familiar menthol flavor of NyQuil may be a bit disappointed. The liquid comes in two flavors: warming berry and vanilla cherry. They both taste good without that medicinal taste that often comes with taking medicine.  Be warned that one of the main ingredients in the liquid is ethanol alcohol.

If you can’t have alcohol, or are giving this to a child over six years old, make sure that you buy the version that contains no alcohol. It should not be given to any children under age six.

The liquicaps contain no alcohol.

The active ingredient is a histamine blocker called diphenhydramine HCI.

Side Effects of ZzzQuil

You may not experience any side effects when using ZzzQuil, but it is helpful to know what some people have reported. Making an informed decision when taking any medication for sleep is always a good idea.

Common side effects:

  • dizziness, drowsiness, loss of coordination
  • dry mouth, nose, or throat
  • constipation, upset stomach
  • dry eyes, blurred vision
  • day-time drowsiness

While none of these side effects are threatening, they aren’t the most comfortable either. You may want to try another sleep aid if you experience any of these symptoms. A natural sleep supplement might be your best option.

Some more serious symptoms, although uncommon, may include:

  • pounding heartbeats
  • painful or difficulty urinating
  • little or no urinating
  • confusion
  • tightness in your neck or jaw

Feeling any of these symptoms might indicate something more serious than just being uncomfortable. If you experience any of these symptoms, consult a doctor right away and let them know that you took diphenhydramine HCI.

Let me reiterate that these are all just possible side effects, and you may not encounter any of them when taking ZzzQuil. These are just things that you should know before taking this sleep aid.

Other precautions

Although there is no risk associated with taking ZzzQuil while pregnant, you should ask your doctor before taking it if you are pregnant. If you are breastfeeding, taking ZzzQuil should be avoided.

Do not give this to children under the age of six.

Don’t drive or operate machinery after you take it as you may be too impaired to safely do so.

Ask a doctor or pharmacist before using this medicine if you are also using any other drugs, including prescription and over-the-counter medicines, vitamins, and herbal products. Some medicines can cause unwanted or dangerous effects when used together.


  • Can be purchased over the counter with no prescription
  • Non-habit forming
  • Comes in liquid and pill form
  • ​Works quickly
  • Doesn’t taste like medicine


  • Doesn’t cure insomnia
  • Liquid contains alcohol
  • Can interact with other drugs
  • Diphenhydramine HCI blocks mental alertness so you shouldn’t take it if you need to be alert when awake

How Does ZzzQuil Work?

The active ingredient in both the liquid and gelcaps is diphenhydramine HCI. It’s the same drug that is found in antihistamine medicines such as Benadryl.

It’s main purpose is to treat allergy and cold symptoms like congestion and itchy, watery eyes by drying out the body.

It also blocks a substance in the body called histamine. Histamine helps keep your brain alert and active. By blocking it, the drug allows a decrease in activity in the brain so you become drowsy.

When Should ZzzQuil Be Used?

ZzzQuil works great as an occasional sleep aid. It won’t cure your insomnia and is not meant to be taken everyday.

It really depends on why you aren’t able to fall asleep as to when or if you should take it.

If you just can’t seem to get your brain to shut off, and this is causing you to lose sleep, then taking ZzzQuil  about an hour before bed will help you fall asleep. It could be that you have a big event the next day and need to make sure that you are rested. In that case, it is an excellent time to take ZzzQuil.

Maybe you have trouble sleeping when you travel. Whether you are on a plane, or you just can’t sleep in an unfamiliar hotel room, ZzzQuil will help you.

 If you have insomnia, then you need something else to treat the issue. ZzzQuil might help you fall asleep, but it won’t cure your insomnia, even if you take it everyday.

Does ZzzQuil Work?

In a word, yes. It will work differently for different people, however. Usually it takes approximately 20 minutes to kick in, and then you will start to feel drowsy.

For others, it may take up to an hour. The liquid generally is absorbed into your system faster than the gelcaps.

It seems that the pills are not quite as effective as the liquid but, again, it depends on the person. For me, that was the case; the pills were not as effective.  For others, the pills may work just as well as the liquid.

Experiment and see how you react to it.

My experience was that it really knocked me out. While watching TV, I found myself dozing off, so I went to bed. I was asleep right away and slept very deeply. The next morning, I did feel a bit groggy, but it wasn’t too bad.

Some people feel refreshed in the morning since they were able to get a deep, restful sleep. Others feel a bit sleepy.

ZzzQuil Review Conclusion

ZzzQuil is an effective way to get some occasional relief from sleeplessness. It does work, and it usually works quite well for most people.

You will increase the effectiveness of this product by also setting yourself up to sleep. Using aromatherapy in your room, setting up some soft lighting, and not using your computer or smartphone just before bed will certainly help.

The best thing you can do for yourself is to develop good bedtime habits that will help you sleep.

 I hoped this ZzzQuil review has been helpful and will improve your quality of sleep.

Buying Options

ZZZquil is an over the counter sleep aid, and can be bought in stores, or online at retailers such as Amazon.com.

ZzzQuil Review
ZzzQuil Review

Images provided by Vicks.

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