Compare amoxicillin vs. penicillin

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

Amoxil (amoxicillin)

Prescription only
Treats bacterial infections.

Amoxil (amoxicillin) is a good and cheap antibiotic that comes in different forms to treat many types of bacterial infections.

3.7/ 5 average rating with 786 reviewsforamoxicillin
Treats bacterial infections.

Penicillin VK (penicillin) is good at treating strep throat and is cheap, however, it can only be used for certain infections as many bacteria have developed resistance to it.

3.9/ 5 average rating with 1297 reviewsforpenicillin
  • First choice medicine to treat many bacterial infections.
  • Available in generic.
  • Available in different forms: tablet, capsule, and liquid. The liquid comes in many different flavors to make it taste better for people who don't like pills.
  • Side effects are generally not too bad compared to other antibiotics.
  • Compared to alternatives, Penicillin VK (penicillin) is the preferred choice for treating strep throat infections.
  • This medicine is available as a generic, which is cheap.
  • It’s also available in different forms: pill and liquid.
  • While Amoxil (amoxicillin) can be used to treat different bacterial infections, many don't respond to it.
  • Can cause diarrhea, nausea, and vomiting.
  • Except for the extended-release form, you have to take Amoxil (amoxicillin) 2 to 3 times a day, which can be hard to remember.
  • The extended-release form can be more expensive because it's a brand name.
  • Many bacteria are resistant to Penicillin VK (penicillin), so it only works for certain infection typically in ear, nose, and throat.
  • Penicillin VK (penicillin) has a bitter taste. Children might not like the taste.
Used for
Dosage forms
  • Pill
  • Chewable tablet
  • Extended-release tablet
  • Liquid
  • Pill
  • Liquid
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786 reviews so far
saidit'sworth it
saiditworked well
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Have you used Amoxil (amoxicillin)?

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1297 reviews so far
saidit'sworth it
saiditworked well
saidit'sa big hassle

Have you used Penicillin VK (penicillin)?

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Side effects
The Amoxil (amoxicillin) FDA package insert doesn’t have numbers about how common side effects are.
The Penicillin VK (penicillin) FDA package insert doesn’t have numbers about how common side effects are.
Risks and risk factors
  • Interaction with birth control
    • Using oral birth control pills
  • Severe diarrhea
    • Taking Amoxil (amoxicillin) for a long time
  • Severe allergic reaction
    • History of penicillin allergies
  • New infections while taking Amoxil (amoxicillin)
    • Weakened immune system
    • Not taking Amoxil (amoxicillin) correctly
  • Rash
    • Mononucleosis
See more detailed risks and warnings
  • Diarrhea
    • Taking Penicillin VK (penicillin) for a long time
  • Interaction with birth control pills
  • Allergic reaction
    • History of severe allergic reaction to Penicillin VK (penicillin)
    • Cephalosporin medication allergy
See more detailed risks and warnings