Fungal skin infections are incredibly common. Athlete’s foot, jock itch, and ringworm are just a few examples of conditions caused by various types of fungi. For many of these infections, a topical treatment is the first line of defense.
One effective option is a cream containing a combination of zinc undecylenate and undecylenic acid, but other antifungal ingredients exist as well. These medications are antifungals. Undecylenic acid is a fatty acid derived from castor oil, and zinc undecylenate is the zinc salt of undecylenic acid. Together, they inhibit the growth of fungi on the skin.
This article provides a comprehensive overview of zinc undecylenate and undecylenic acid cream, including its uses, how it works, and essential considerations for both patients and healthcare professionals so you can make a more informed decision about the best treatment for you.
What are undecylenic acid and zinc undecylenate?
You’ll find undecylenic acid and zinc undecylenate in many over-the-counter antifungal creams and powders. But what are they?
Chemical Properties
Undecylenic acid is a monounsaturated fatty acid that comes from castor oil. You may also see it called 10-undecenoic acid. The chemical formula is CH2=CH(CH2)8COOH.
Zinc undecylenate is simply what happens when you combine undecylenic acid with zinc. It’s the zinc salt of undecylenic acid, if you want to get technical about it.
How They Work
Both undecylenic acid and zinc undecylenate have antifungal properties. They don’t necessarily kill fungi, but they keep them from growing and spreading.
Zinc undecylenate may kill fungi if it’s used regularly over a long period of time.
These chemicals work by disrupting the cell membranes of the fungi and preventing them from forming biofilms, growing hyphae (root-like structures), and using enzymes to metabolize lipids.
These substances are effective against Candida albicans and other fungi that cause skin infections.
Indications and uses
Zinc undecylenate and undecylenic acid cream is mainly used to treat superficial fungal infections on your skin, such as:
- Athlete’s foot (tinea pedis)
- Ringworm (tinea corporis)
- Other fungal infections (as directed by a healthcare professional)
You can buy this cream over the counter in many different forms, like creams, ointments, solutions, powders, sprays, and gels. Because of its ready availability, it can be tempting to self-diagnose and treat a skin condition with readily available remedies like apple cider vinegar for fungal infections. However, it’s important to get the right diagnosis from a doctor or other healthcare provider before you start treatment. That way, you can be sure you’re using the right medicine for your specific condition.
Dosage and Administration
Before applying any zinc undecylenate or undecylenic acid product, make sure to wash and dry the affected skin thoroughly.
Here are some guidelines for using the different dosage forms:
- Cream: Apply a thin layer to the affected area and rub it in well. Really get it in there.
- Powder: Sprinkle the powder between your toes, on your feet, and inside your socks and shoes.
- Aerosol spray: Spray the affected area from 4-6 inches away.
Keep up with your treatment for at least two weeks after your symptoms disappear. If your symptoms don’t get better or get worse, talk to your doctor.
Precautions and Contraindications
Before using a zinc undecylenate and undecylenic acid cream, keep the following in mind:
- Allergies: Tell your doctor or pharmacist about any known allergies you have, especially to undecylenic acid, zinc undecylenate, or any other ingredients in the cream. Allergic reactions can happen, so it’s better to be safe than sorry.
- Use in children: Unless your pediatrician recommends it, don’t use this cream on children younger than two years old.
When to call your doctor: It’s time to consult a professional if:
- Your condition doesn’t improve after four weeks of treatment.
- Your condition worsens while using the cream.
Potential side effects
Like any medication, zinc undecylenate and undecylenic acid cream can cause side effects. Most are mild, but some can be serious.
Common side effects include:
- Skin irritation
- Burning
- Itching
- Redness at the application site
Rare, but serious side effects include allergic reactions. Seek immediate medical attention if you experience a rash, hives, swelling, or difficulty breathing.
Drug Interactions
Because not much is known about drug interactions with topical undecylenic acid and zinc undecylenate, it’s important to be careful. Tell your doctor about everything you’re taking, even if it’s just an over-the-counter medication or herbal supplement. Better safe than sorry!
Special populations: Pediatric and geriatric considerations
Thinking about using zinc undecylenate and undecylenic acid cream on a young child? It’s generally not recommended for children under two years of age unless a doctor specifically advises it. So, check with your pediatrician first.
For older adults, there haven’t been specific studies done on this particular cream, so we don’t know about any special considerations. But it’s always a good idea to use caution and follow the directions carefully, no matter what your age.
And no matter who’s using it, keep a close eye out for any unusual reactions or side effects.
Storage and handling
You’ll want to store your zinc undecylenate and undecylenic acid cream at room temperature, away from heat, moisture, and direct light.
Also, as with any medication, make sure you keep this cream in a place where children can’t get to it.
Pharmacology and Toxicology
When you use zinc undecylenate and undecylenic acid cream topically, there’s not much information available about how it gets absorbed into your system, how your body breaks it down, or how it gets eliminated.
As far as toxicity goes, studies on animals show that the dose that would be lethal to 50% of a rat population (LD50) is 2500 mg/kg when taken orally. For mice, the oral LD50 is 8150 mg/kg.
The data is limited when it comes to whether this cream causes cancer, genetic mutations, birth defects, or developmental problems.
Research and clinical trials
There’s a fair amount of research on undecylenic acid and its antifungal properties. Some in vitro studies (meaning, studies done in a lab, not on living creatures) have shown that it can inhibit biofilm and hyphal growth.
However, there’s not a lot of clinical trial data out there, meaning that the research hasn’t been duplicated in human trials.
Key Takeaways
Zinc undecylenate and undecylenic acid cream are antifungal medications you can buy without a prescription to treat common skin infections. They’re available in many different formulations, so it’s important to read the directions carefully.
While these creams are generally safe, you should always follow the directions, take any listed precautions, and talk to your doctor or other health professional if you have questions or concerns.
It’s worth noting that more research is needed to understand how these creams might interact with other drugs, or to determine whether they have any long-term effects.