Compare Benadryl vs. Robitussin

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

Benadryl (Diphenhydramine)

Prescription or OTC

Robitussin (Guaifenesin)

Over-the-counter
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.

4.1/ 5 average rating with 294 reviewsforBenadryl
Breaks up mucus that causes cough.

Robitussin (Guaifenesin) is a useful medicine for loosening congestion in your chest and throat, but it doesn't last as long as other guaifenesin products.

Upsides
  • 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.
  • Robitussin (Guaifenesin) reduces the thickness and amount of mucus in your throat and chest.
  • It’s available at the drugstore either by itself or in combination with other medications to treat cold and flu symptoms.
  • Available in multiple forms.
  • Can be used in children 12 years and older.
Downsides
  • 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.
  • Robitussin (Guaifenesin) doesn't last as long as other products that contain guaifenesin. Mucinex's extended release form lasts 12 hours and Robitussin (Guaifenesin)'s lasts 8 hours.
  • You need to drink a lot of fluids while taking this medication or it won't work as well.
  • Robitussin (Guaifenesin) isn’t useful if you have a dry cough.
  • Can cause nausea, headache, and an upset stomach.
Used for
Dosage forms
  • Pill
  • Oral solution
  • Cream, gel, or ointment
  • Liquid
No pricing information available
No pricing information available
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Reviews
294 reviews so far
86%
saidit'sworth it
59%
saiditworked well
8%
saidit'sa big hassle

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Side effects
The Benadryl (Diphenhydramine) FDA package insert doesn’t have numbers about how common side effects are.
The Robitussin (Guaifenesin) FDA package insert doesn’t have numbers about how common side effects are.
Risks and risk factors
  • Overdose
    • Using other drugs with the same ingredients
  • Increased side effects
    • Age 65 years or older
  • Driving impairment
    • Taking with alcohol
    • Taking other medicines that make you less alert
  • Hyperactivity
    • Children age 6 years and younger
  • Trouble urinating
    • Enlarged prostate
    • History of bladder problems
  • Vision changes
    • Glaucoma
  • Breastfeeding
    • Nursing mothers
See more detailed risks and warnings
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Disclaimer: We don't provide medical advice. If you think you might have a medical emergency, call your doctor or 911 immediately.