Compare Zyrtec vs. Benadryl

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

Zyrtec
(cetirizine)

Benadryl
(diphenhydramine)

Treats allergy symptoms. Zyrtec (Cetirizine) is a once-daily allergy relief medication that won't make you feel too sleepy.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.
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Prices and coupon for 30 (24 hour) tablets of cetirizine
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Prices and coupon for 30 (25mg) capsules of diphenhydramine
Reviews & ratings
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Filter group. All currently selected
5.17Zyrtec
Reviews for Zyrtec (cetirizine)
76%
of people (All ages) say Zyrtec (cetirizine) is worth it
47%
say it works well
7%
say it's a big hassle
1232 reviews
Have you used Zyrtec (cetirizine)?
Worth itNot sureNot worth it
Reviews for Benadryl (diphenhydramine)
86%
+10% better vs. Zyrtec (cetirizine)
59%
+12% better vs. Zyrtec (cetirizine)
8%
-1% worse vs. Zyrtec (cetirizine)
294 reviews
Have you used Benadryl (diphenhydramine)?
Worth itNot sureNot worth it
Side effects
ZyrtecBenadryl

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

FDA side effect reports for Zyrtec »

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

FDA side effect reports for Benadryl »
How it works
ZyrtecBenadryl
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.Benadryl (Diphenhydramine) is an antihistamine. It blocks histamine, a chemical that causes congestion, itching, and other allergic reactions. It also makes you sleepy.
Type of medication
ZyrtecBenadryl
Prescription or OTC
Prescription or OTC
Available as
ZyrtecBenadryl
  • Pill
  • Liquid capsule
  • Dissolving tablet
  • Liquid
  • Pill
  • Oral solution
  • Cream, gel, or ointment
Used for
ZyrtecBenadryl
Risk factors for serious side effects
ZyrtecBenadryl
    • 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 »
    • 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 »
    Pregnancy

    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.

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

    Alcohol
    ZyrtecBenadryl
    No alcohol related info.
    • Don't take it with alcohol or other drugs that make you sleepy.
    Kidneys and liver
    ZyrtecBenadryl
    • 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.
    No kidneys and liver related info.
    Sleep
    ZyrtecBenadryl
    • Can make you feel sleepy, so take it at bedtime if needed.
    • Benadryl (Diphenhydramine) makes you more tired than Claritin, Allegra, or Zyrtec.
    • Benadryl (Diphenhydramine) makes you tired, so take it before you go to sleep.
    Upsides and benefits
    ZyrtecBenadryl
    • 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 can provide quick relief of allergy symptoms for both kids and adults.
    • 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).
    • Benadryl (Diphenhydramine) is often better than other antihistamines at treating allergy symptoms and hives.
    • It can provide quick relief of allergy symptoms for both kids and adults.
    • 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.
    Downsides and risks
    ZyrtecBenadryl
    • 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.
    • 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.
    Tips from our pharmacists for people taking the medication
    ZyrtecBenadryl
    • 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.
    • 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.
    Learn more
    More about ZyrtecSide effectsReviews & ratingsAlternativesFDA package insert
    Have you used Zyrtec (cetirizine)?
    Worth itNot sureNot worth it
    More about BenadrylSide effectsReviews & ratingsAlternativesFDA package insert
    Have you used Benadryl (diphenhydramine)?
    Worth itNot sureNot worth it