What Is The Difference Between Benadryl And ZzzQuil?

In our latest question and answer, the pharmacist discusses the differences between Benadryl and ZzzQuil.


What is the difference between Benadryl and ZzzQuil? I want something for sleep. Thank you!

Asked by Beatrice On Aug 10, 2021

Answered by
Medical Content Reviewed By HelloPharmacist Staff

On Aug 11, 2021

Key points

  • Both Benadryl and ZzzQuil contain the same active ingredient (diphenhydramine).
  • Both Benadryl and ZzzQuil are available in a liquid and Liquicap dosage form.
  • ZzzQuil liquid contains alcohol (10%) while Benadryl liquid (i.e. Children's Benadryl) does not. There is also a non-alcoholic version of ZzzQuil on the market.
  • ZzzQuil liquid contains high fructose corn syrup while Children's Benadryl liquid contains sucrose (i.e. table sugar).

Hello and thank you for reaching out to us!

The difference between Benadryl and ZzzQuil is mostly marketing, as they contain the same active ingredient.

In fact, in many situations, you could easily substitute one for the other.

Benadryl And ZzzQuil Both Contain Diphenhydramine

Both Benadryl and ZzzQuil have the same active ingredient, diphenhydramine, and thus, work the same way.

Although Benadryl is traditionally used to help with allergy symptoms (e.g. itchy eyes, runny nose, hives, etc...), many people use it to help them fall asleep, as it is quite sedating.

ZzzQuil is essentially a way to market the sedative effects of diphenhydramine as a sleep aid.

Below are the 'Drug Facts' for both Benadryl tablets and ZzzQuil liquid. You can see that the active ingredient, diphenhydramine, is the same.

ZzzQuil Drug Facts

Benadryl Drug Facts

Although they contain the same active ingredients, Benadryl and ZzzQuil do come in different dosage forms, with different inactive ingredients.

It is important to note (as I detail below), that ZzzQuil liquid does contain alcohol, which can enhance its sedating effects (although there is now a non-alcohol version on the market too).

Benadryl And ZzzQuil Dosage Forms

Both Benadryl and ZzzQuil are available in multiple dosage forms, including:

  • Liquid
  • Tablets
  • LiquiCaps

For the solid dosage form products (e.g. tablets, LiquiCaps), Benadryl and ZzzQuil contain 25 mg of diphenhydramine per Liquicap/tablet.

The liquid form of ZzzQuil contains contain 50 mg of diphenhydramine per 30mL.

Benadryl is also available in additional dosage forms that ZzzQuil is not available in, including:

  • Tablets
  • Chewable tablets

Lastly, I do want to point out ZzzQuil has a product that contains melatonin, instead of diphenhydramine, and is called ZzzQuil Pure Zzzs

Benadryl And ZzzQuil Inactive Ingredients

When it comes to the liquid forms of the drugs, ZzzQuil contains alcohol (10% by volume) while the Benadryl liquid does not contain any alcohol.

In fact, Benadryl as a liquid only comes as a "children's liquid", which is still the same active ingredient (diphenhydramine), just alcohol-free.

The concentration of the ZzzQuil liquid is:

  • 50 mg diphenhydramine per 30 mL (two tablespoonfuls).

The concentration of Children's Benadryl liquid is:

  • 12.5 mg diphenhydramine per 5 mL (one teaspoonful).

The complete ZzzQuil liquid inactive ingredient list is as follows:

  • Alcohol
  • Citric acid anhydrous
  • FD&C Blue No. 1
  • FD&C Red No. 40
  • Flavor
  • High fructose corn syrup
  • Polyoxyl 40 stearate
  • Propylene glycol
  • Purified water
  • Saccharin sodium
  • Sodium benzoate
  • Sodium citrate

The complete Benadryl Children's liquid inactive ingredient list is as follows:

  • Anhydrous citric acid
  • D&C red no. 33
  • FD&C red no. 40
  • Flavors
  • Glycerin
  • Monoammonium glycyrrhizinate
  • Poloxamer 407
  • Purified water
  • Sodium Benzoate
  • Sodium chloride
  • Sodium citrate
  • Sucrose

Besides the addition of alcohol to ZzzQuil liquid, it also contains high fructose corn syrup. Children's Benadryl liquid does not contain high fructose corn syrup, but sucrose instead.

Please don't hesitate to reach out to us again with any additional questions!


About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 11 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication related questions!

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