Benefits and Risks of Undecylenic Acid, According to Experts

Fungal infections like athlete’s foot, jock itch, and ringworm are common occurrences and must be treated with antifungal agents. Undecylenic acid is one of the most effective antifungal agents for treating these conditions. It is derived from castor oil and naturally occurs in human sweat (1). This article explains the benefits of undecylenic acid, its use, and precautions to take while using it. Keep reading.

• What Is Undecylenic Acid?
• Benefits Of Undecylenic Acid For Skin
• How To Use Undecylenic Acid
• Side Effects Of Undecylenic Acid
• Precautions To Take While Using Undecylenic Acid

What Is Undecylenic Acid?

“Undecylenic acid is a fatty acid that is used for antifungal, antibacterial, and keratolytic effects. It belongs to the group of lipophilic (fat-loving) acids,” says board-certified dermatologist Dr. Paula Morgan.

Undecylenic acid is a common ingredient in medicated creams and lotions to treat ringworm, fungal infections, and other cutaneous conditions. However, it is never used on its own for treating fungal skin infections. You will find the salts of undecylenate (like zinc undecylenate) as an antifungal agent in OTC creams and lotions (1).

Undecylenic acid is derived from the distillation of castor oil, decomposing ricinoleic acid in high temperatures (through pyrolysis). It naturally occurs in human sweat (1).

Undecylenic acid also works as an antibacterial agent and an active ingredient in topical medications. It may help the skin in numerous ways.

Benefits Of Undecylenic Acid For Skin

The zinc salt of undecylenic acid is beneficial in treating conditions like(1):

• Fungal infections (athlete’s foot, jock itch)
• Eczema
• Ringworm
• Other skin conditions

The zinc in it has astringent effects that reduce irritation and discomfort. It is also effective against conditions caused by Candida albicans (1),(2).

It may also help in acne management. While undecylenic acid may not kill acne- causing bacteria, it may regulate certain factors that may prevent acne.

Dr. Morgan explains, “The number of bacteria on the skin increases by approximately 1000 times when we sweat. By using an antibacterial agent, we can fight and prevent bacterial infections and thus prevent acne. Undecylenic acid belongs in this category of substances. It makes the surface of the skin rougher so that the pores are closed more tightly, and dirt does not come into direct contact with them, which is the foundation of the formation of acne. It improves skin regeneration and wound healing, which can lead to a more rapid recovery from pimples and inflammations caused by them.”

While undecylenic acid is not a cosmetic ingredient, it is still used in cosmetic formulations for its antifungal and other benefits. Dr. Morgan elaborates, “Undecylenic acid as fatty acid is contained in many vegetable oil products, e.g., in wheat germ oil or sunflower seed oil. In concentrations up to 10%, it can be found in sunscreens and other cosmetic products. Undecylenic acid is also an ingredient of many hair shampoos that are used for greasy hair or dandruff. As a lipophilic substance, undecylenic acid strengthens the outer skin layers and fights flaking and itching of the scalp.”

The usage of undecylenic acid is not restricted to just topical ointments and antifungal creams. Therefore, it is best to follow the doctor’s or the manufacturer’s instructions for proper usage. Here are a few tips.

How To Use Undecylenic Acid

The use of undecylenic acid will differ according to the type of product. As a rule of thumb, if you are using a topical cream or powder or spray, apply it to clean and dry skin twice a day or as instructed by the doctor. However, make sure you

• apply it only to the affected area(s)
• choose a product according to the application area (nail or skin)
• read the instructions and follow the precautions

The percentage of undecylenic acid in OTC products is often quite low, and such products may not work on severe infections. In that case, you might need prescription-strength products.

If the OTC product you are using is not working, consult a doctor immediately. Most of the fatty acids and fatty acid salts are considered safe for use. However, there are chances of side effects.

Side Effects Of Undecylenic Acid

Dr. Morgan says, “The use of undecylenic acid is generally considered safe. The only known side effect is a slight burning sensation when the product is applied to the skin. It should not be used by pregnant women or nursing mothers.”

She adds, “No interactions with other drugs have been reported with undecylenic acid, and long-term use is possible without any side effects.”

The Cosmetic Ingredient Review (CIR) considers undecylenic acid and its salts safe for use. However, one person reported symptoms like swelling, itching, dryness, and oozing from the feet after using 10% undecylenic acid cream for three days. The symptoms were gone after discontinuing the medication (3). Therefore, it is crucial to follow the doctor’s instructions and take precautions while using undecylenic acid for skin conditions.

Precautions To Take While Using Undecylenic Acid

Always consult a doctor to determine the frequency of usage.

Closing Thoughts

Undecylenic acid is unlike the other facial acids you have heard of. It is an antifungal ingredient used to treat fungal infections like ringworm, jock itch, athlete’s foot, and similar issues. It is available as OTC and prescription- strength medications and is quite effective in providing relief. It may also be used for other bacterial skin conditions and eczema. The formulation of products with undecylenic acid and its strength may differ according to the condition and body part. Hence, it is best to avoid the unregulated use of undecylenic acid. Avoid it if you are pregnant or lactating, and consult a doctor before using it.

Frequently Asked Questions

How long can you use undecylenic acid?

Use undecylenic acid products until the infection is gone or as directed by the doctor.

Can I use undecylenic acid on my face?

It depends. Undecylenic acid products are formulated differently for different body parts like the nails, groin, and feet. It is best to consult a doctor before using any formulations on the face.

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