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Overview: Undecylenic acid is used on the skin to treat athlete’s foot, jock itch, and ringworm. Clean and dry your skin well before using undecylenic acid. Wash your hands after using it. Stop using this medicine and tell your health care provider if you get skin irritation.

Uses

What is undecylenic acid used for?

Undecylenic acid is commonly used to treat the following fungal skin infections.

Undecylenic acid may also be used for other conditions as determined by your health care provider.

How does undecylenic acid work (mechanism of action)?

Undecylenic acid is an antifungal medicine. It appears to kill certain fungi, preventing them from causing harm to your skin.

How is undecylenic acid supplied (dosage forms)?

Brands and other names

  • Derman
  • Desenex
  • Fungoid AF
  • Hongo Cura
  • Terpinicol
  • Tripenicol

Example dosage forms and strengths

  • 13%, 20% topical cream
  • 25% topical gel
  • 25% topical liquid
  • 25% topical solution
  • 10%, 20% topical spray

How should I store undecylenic acid?

Undecylenic acid should generally be stored at a temperature between 59 F and 86 F (15 C and 30 C). Some products have not been provided with storage requirement information on their packaging. Most medicines should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight. Ask your pharmacist if you are unsure how to store your undecylenic acid product. 

Side Effects

What are the most common side effects of undecylenic acid?

Undecylenic acid is generally well tolerated. 

There may be side effects of undecylenic acid that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of undecylenic acid?

While less common, the most serious side effects of undecylenic acid are described below, along with what to do if they happen.

Severe Allergic Reactions. Undecylenic acid may cause allergic reactions, which can be serious. Stop using undecylenic acid and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Skin Irritation. Undecylenic acid may irritate your skin where it is used. Stop use and tell your health care provider if you have skin irritation.

Warnings & Precautions

Who should not use undecylenic acid?

Allergies to Ingredients. People who are allergic to any of the following should not use undecylenic acid.

  • Derman
  • Desenex
  • Fungoid AF
  • Hongo Cura
  • Terpinicol
  • Tripenicol
  • Undecylenic acid
  • Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific undecylenic acid products they stock.

Children Under Two Years of Age. Children less than 2 years old should not use undecylenic acid unless directed by a health care provider.

What should I know about undecylenic acid before using it?

Follow the instructions that come with the product.

Keep undecylenic acid out of the reach of children.

Undecylenic acid is for use on the skin only. Do not use this medicine on your scalp or nails. Keep undecylenic acid away from your eyes. If you get undecylenic acid in your eyes, rinse them right away with cool water. 

Clean and thoroughly dry the treated area before using undecylenic acid. 

If you are using undecylenic acid for athlete’s foot, wear well-fitting, ventilated footwear. Change your shoes and socks at least once daily.

Wash your hands after using undecylenic acid.

Avoid heat or flame (including smoking) while using undecylenic acid 20% topical spray. The contents are flammable.

What should I tell my health care provider before using undecylenic acid?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if undecylenic acid is right for you.

In particular, make sure that you discuss any of the following.

Other Medicines and Supplements. Undecylenic acid may interact with other medicines and supplements. Before using undecylenic acid, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how undecylenic acid could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if undecylenic acid passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does undecylenic acid interact with foods or drinks?

There are no known interactions between undecylenic acid and foods or drinks.

It is unknown if drinking alcohol will affect undecylenic acid, but heavy drinking can slow your immune response and make it harder for your body to fight infections.

Does undecylenic acid interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any cleansers or other medicines on your skin.

This may not be a complete list of medicines that can interact with undecylenic acid. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much undecylenic acid?

If you or someone else has used too much undecylenic acid, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of undecylenic acid?

If you miss a dose, use it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only use the next dose. Do not use double or extra doses.

It is important to complete your treatment with undecylenic acid, even if your symptoms get better or go away. Follow the instructions that come with the product or direction from your health care provider. Using the medicine as directed will reduce the risk that future infections are resistant to undecylenic acid  or other similar medicines.