Hydrogen peroxide (By mouth)

Hydrogen Peroxide (HYE-droe-jen per-OX-ide)

Treats canker sores, minor mouth wounds, and swollen gums.

Brand Name(s):

Orajel Perioseptic, Peroxyl

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is generally considered safe for most people. Talk to your doctor if you have concerns.

How to Use This Medicine:

Gel/Jelly, Liquid

  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • Follow the instructions on the medicine label if you are using this medicine without a prescription.
  • Place the liquid medicine in your mouth but do not swallow it. Swish the liquid around in your mouth for at least 1 minute, and then spit it out.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

Warnings While Using This Medicine:

  • Do not swallow this medicine. If you swallow more than 2 teaspoons, call your doctor or a poison center right away.
  • Supervise children while they use this medicine.
  • Do not use this medicine for more than 7 days unless your doctor has told you to.
  • Call your doctor if your symptoms do not improve or if they get worse.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088


Last Updated: 9/6/2024

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites.

All rights reserved

A.D.A.M. content is best viewed in IE9 or above, Firefox and chrome browser.