Hydrogen peroxide (By mouth)


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

Treats canker sores, minor mouth wounds, or swollen gums caused by braces, dentures, dental procedures, or accidental injury to your mouth.

Brand Name(s)


When This Medicine Should Not Be Used

How to Use This Medicine

Gel/Jelly, Liquid

  • Take your medicine as directed.
  • Follow the instructions on the medicine label if you are using this medicine without a prescription.
  • Place the liquid form of this medicine in your mouth but do not swallow it. Hold and swish the liquid in your mouth for at least one minute and then spit it out.
  • To use the gel/jelly form of this medicine, cut the tube open with a clean pair of scissors. Use the mark on the applicator tip as a guide for where to cut. Apply several drops to the affected area in your mouth. Hold the gel in your mouth for at least one minute and then spit it out.
  • Use this medicine after meals and at bedtime, unless otherwise directed by your doctor. Do not use the medicine more than 4 times daily or for longer than 7 days unless your doctor tells you to.

How to Store and Dispose of This Medicine

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

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 a child or adult accidentally swallows more than 2 teaspoons of this medicine, call your doctor or a poison control center right away.
  • Children should be supervised while using this medicine. This medicine should not be used on a child under 2 years of age.
  • Call your doctor if your symptoms do not improve or if they get worse.

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 these less serious side effects, talk with your doctor:

  • Burning or stinging of your mouth sores when you rinse with the medicine.
  • Unpleasant taste in your mouth.

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

Version Info

  • Last reviewed on 8/4/2014

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch)

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. © 1997- 2013 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.