Compare Benadryl vs. Zyrtec

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Benadryl
(Diphenhydramine)

Zyrtec
(Cetirizine)

Treats allergy symptoms and helps you sleep. Benadryl (Diphenhydramine) is great for allergies, but curl up on the couch after taking it and get ready for a nap.Treats allergy symptoms. Zyrtec (Cetirizine) is a once-daily allergy relief medication that won't make you feel too sleepy.
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Reviews & ratings
Button Group. All currently active
Button Group. All currently active
5.5767790262172285Benadryl
Reviews for Benadryl (Diphenhydramine)
85%
of people say Benadryl (Diphenhydramine) is worth it
57%
say it works well
8%
say it's a big hassle
Reviews for Zyrtec (Cetirizine)
76%
9% vs. Benadryl (Diphenhydramine)
46%
11% vs. Benadryl (Diphenhydramine)
7%
+1% vs. Benadryl (Diphenhydramine)
Side effects
BenadrylZyrtec

We haven’t found good data for Benadryl side effects.

FDA side effect reports for Benadryl »

We haven’t found good data for Zyrtec side effects.

FDA side effect reports for Zyrtec »
How it works
BenadrylZyrtec
Benadryl (Diphenhydramine) is an antihistamine. It blocks histamine, a chemical that causes congestion, itching, and other allergic reactions. It also makes you sleepy.Zyrtec (Cetirizine) is an antihistamine. It blocks histamine, a chemical that causes congestion, itching, and other allergic reactions. Antihistamines can also make you sleepy, but Zyrtec is a low-drowsiness version.
Type of medication
BenadrylZyrtec
Antihistamine
1st generation
Prescription or OTC
Antihistamine
2nd generation
Prescription or OTC
Available as
BenadrylZyrtec
  • Pill
  • Oral solution
  • Cream, gel, or ointment
  • Pill
  • Liquid capsule
  • Dissolving tablet
  • Liquid
Used for (click to learn more)
BenadrylZyrtec
Risk factors for serious side effects
BenadrylZyrtec
  • Using other drugs with the same ingredients
  • Age 65 years or older
  • Taking with alcohol
  • Taking other medicines that make you less alert
  • Children age 6 years and younger
  • Enlarged prostate
  • History of bladder problems
  • Glaucoma
  • Nursing mothers
Detailed Benadryl (Diphenhydramine) risks & warnings »
    • Age 65 or older
    • Taking with alcohol
    • Taking other medicines that make you less alert
    • Current kidney disease
    • Current liver disease
    Detailed Zyrtec (Cetirizine) risks & warnings »
    Pregnancy category
    BenadrylZyrtec
    BFDA pregnancy category (Probably safe)

    Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

    See the FDA package insert
    NFDA pregnancy category (Unknown)

    The FDA hasn’t classified this medicine’s effects on unborn babies. Talk with your doctor about this medicine if you’re pregnant or planning on it.

    See the FDA package insert
    Alcohol
    • Don't take it with alcohol or other drugs that make you sleepy.
    No specific alcohol-related info.
    Food
    No specific food-related info.No specific food-related info.
    Kidneys and liver
    No specific kidneys and liver-related info.
    • People with kidney or liver disease may need to take a lower dose of Zyrtec (Cetirizine) to prevent overdose. Talk with your doctor to be sure you are using the correct dose.
    Sex
    No specific sex-related info.No specific sex-related info.
    Sleep
    • Benadryl (Diphenhydramine) makes you tired, so take it before you go to sleep.
    • People age 65 years and older have a higher risk of side effects from taking antihistamine medications like Benadryl (Diphenhydramine). Watch for changes in vision, severe dry mouth, trouble urinating, or constipation. The drowsiness caused by Benadryl (Diphenhydramine) can make you "unsteady" on your feet, leading to a higher chance of falls.
    • People age 65 and older have a higher risk of troublesome side effects from taking antihistamine medications like Zyrtec (Cetirizine). Watch out for changes in vision, severe dry mouth, trouble urinating, or constipation. Also, feelings of drowsiness may leave you "unsteady" on your feet. This can make you more likely to fall causing broken bones or other serious injuries. Talk with your doctor before using Zyrtec (Cetirizine) and stop using it if you have side effects.
    Weight
    No specific weight-related info.No specific weight-related info.
    Upsides and benefits
    BenadrylZyrtec
    • Benadryl (Diphenhydramine) is often better than other antihistamines at treating allergy symptoms and hives.
    • It makes you sleepy, so it'll help if your allergies are bothering you at night.
    • The effects wear off in 4 to 6 hours, so side effects don't last that long.
    • It comes as a tablet, capsule, liquid, and quick dissolving tablet.
    • It can provide quick relief of allergy symptoms for both kids and adults.
    • Zyrtec (Cetirizine) works as well as other antihistamines to treat sneezing and runny nose, but causes less sedation.
    • Works well to also treat hives and itchy skin.
    • Zyrtec (Cetirizine) is available over the counter without a prescription.
    • It comes as a tablet, liquid, and quick-dissolving tablet.
    • It's okay to take with most other medications because it has few drug interactions.
    • Most people don't get any side effects from Zyrtec (Cetirizine).
    • It can provide quick relief of allergy symptoms for both kids and adults.
    Downsides and risks
    BenadrylZyrtec
    • Benadryl (Diphenhydramine) makes you more tired than Claritin, Allegra, or Zyrtec.
    • You shouldn't drive after taking Benadryl (Diphenhydramine) until you know how it affects you.
    • Talk to a pediatrician before giving Benadryl (Diphenhydramine) to a child.
    • It can increase the risk of falls, so elderly people shouldn't use Benadryl (Diphenhydramine).
    • Don't use Benadryl (Diphenhydramine) if you are breastfeeding.
    • Although it works fast, its effectiveness wears off for some people over time.
    • Zyrtec (Cetirizine) can be slightly more sedating than Allegra or Claritin.
    • Some people find that other more sedating antihistamines, like Benadryl, are more effective for them than Zyrtec (Cetirizine).
    • If you have daily allergy symptoms, a prescription nasal steroid spray might be better for you long-term.
    Tips from our pharmacists for people taking the medication
    BenadrylZyrtec
    • Take it as needed every 4 to 6 hours.
    • Benadryl (Diphenhydramine) can make you dehydrated, so avoid this side effect by drinking plenty of fluids.
    • Benadryl (Diphenhydramine) makes you tired, so take it before you go to sleep.
    • Don't take it with alcohol or other drugs that make you sleepy.
    • If you need to use it for more than a few weeks, talk with your doctor. A different medication might work better for you long-term.
    • If you only have itchy or watery eyes, try using just an antihistamine eye drop.
    • Starts working in a few hours. Only take it once a day.
    • Can make you feel sleepy, so take it at bedtime if needed.
    • Avoid some of the side effects by drinking plenty of non-caffeinated liquids.
    • If you need to use it for more than a few weeks, talk with your doctor about trying a nasal steroid instead since it might work better for you long-term.
    • Using an antihistamine eye drop instead can also work better to treat itchy or watery eyes.
    Learn more
    More about BenadrylSide effectsReviews & ratingsAlternativesFDA package insert
    More about ZyrtecSide effectsReviews & ratingsAlternativesFDA package insert