Compare Zofran vs. Phenergan

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

Zofran (Ondansetron)

Prescription only

Phenergan (Promethazine)

Prescription only
Helps you feel less queasy.

Zofran (Ondansetron) works well to prevent nausea and vomiting, and it's available in different forms that you don't have to swallow.

4.9/ 7 average rating with 366 reviewsforZofran
Helps you feel less queasy.

Phenergan (Promethazine) is used to treat and prevent nausea and vomiting from surgery, motion sickness, or pregnancy. While it's cheap and available in different forms to make it easier to take, it can make you feel very sleepy, and its side effects mean that children under 2 and adults over 65 shouldn't take it.

6.1/ 7 average rating with 38 reviewsforPhenergan
Upsides
  • Available in generic.
  • Available in forms that you don't have to swallow (like a tablet or film that dissolves in your mouth) if you're having trouble keeping anything down.
  • Starts working fast (in 30 minutes.
  • Available in generic.
  • Available as a syrup or tablet that you can take by mouth, or as a rectal suppository if you're unable to take anything by mouth.
Downsides
  • Can cause headaches.
  • Can interact with antidepressants.
  • Can only be used to prevent nausea and vomiting, not to treat if it's already happening.
  • Can make you feel very sleepy, especially if you're taking other drugs that can make you sleepy or if you drink alcohol.
  • Can't be used in children under 2 years of age or if you're over 65 because of increased risk from side effects.
  • Can make your skin more sensitive to the sun.
Used for
Dosage forms
  • Pill
  • Dissolving tablet
  • Liquid
  • Sublingual film
  • Pill
  • Liquid
  • Suppository
Price
Lowest price near you
$13.13
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Lowest price near you
$6
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Reviews
366 
66%
think this treatment is worth it
51%
think this treatment works well
15%
think this treatment is a hassle

Have you used Zofran (Ondansetron)?

Leave a review
38 
82%
think this treatment is worth it
76%
think this treatment works well
5%
think this treatment is a hassle

Have you used Phenergan (Promethazine)?

Leave a review
Side effects
5possible side effects
  • Headache
    17%
  • Diarrhea
    16%
  • Constipation
    11%
  • Fever
    8%
  • Increased AST and ALT
    5%
See more detailed side effects
The Phenergan (Promethazine) FDA package insert doesn’t have numbers about how common side effects are.
Risks and warnings
  • Heart rhythm problems

    Long QT syndrome

See more detailed risks and warnings
  • Slowing or stopping of breathing

    Children under 2 years of age

  • Seizures

    History of seizures

  • Involuntary muscle movements

    Age over 65

See more detailed risks and warnings