Zinc Undecenoate
Is It Right for You?
A complete guide to Zinc Undecenoate — what it treats, how it works, dosages, side effects, and when a clinician may prescribe it following an online consultation.
What Is Zinc Undecenoate?
Zinc undecenoate is a topical antifungal, the zinc salt of undecenoic acid. It is used to treat fungal skin infections such as athlete's foot, helping to clear the infection while soothing and protecting the skin.
It is usually combined with undecenoic acid in creams, ointments, and powders. The undecenoic acid provides the main antifungal action, while the zinc adds a soothing, drying, and astringent effect.
Some zinc undecenoate products are available to buy, while certain preparations are prescription-only in the UK. A licensed clinician can review your skin through a telehealth consultation and prescribe where appropriate.
What Conditions Is Zinc Undecenoate Used For?
Zinc undecenoate is used for:
treating the fungal infection on the feet and between the toes, easing itching and scaling.
treating ringworm-type infections on the body where appropriate.
the zinc adds a soothing, drying effect that helps calm and protect the skin.
Fungal infections often return if treatment stops too early. Keep using zinc undecenoate for the full recommended time, usually continuing for a period after the skin has cleared, to fully treat the infection.
How Does Zinc Undecenoate Work?
Zinc undecenoate releases undecenoic acid on the skin, which has antifungal activity. It works by stopping the growth of the fungi (dermatophytes) that cause infections like athlete's foot.
By inhibiting the fungus, it allows the infected skin to recover, reducing itching, redness, and scaling.
The zinc part adds a soothing, mildly astringent and protective effect, helping to dry and calm the affected skin while the antifungal action clears the infection.
Dosages & Administration
The correct dose depends on the type and severity of infection, age, weight, and kidney function. Always follow your clinician's instructions. The table below is for general reference only.
Administration Tips
Wash and dry the area well first, especially between the toes, then apply as directed and wash your hands afterwards.
Keep using it for the full course, including after the skin looks normal, and keep feet clean, dry, and aired to help prevent recurrence.
Side Effects of Zinc Undecenoate
Zinc undecenoate is generally well tolerated. Side effects are local and uncommon.
- Mild skin irritation or stinging
- Redness at the application site
- Itching
- Dryness
- Severe irritation, blistering, or burning
- Signs of an allergic skin reaction (worsening rash, swelling)
- Spreading or worsening infection
- Severe allergic reaction
If your skin does not improve after the recommended period, worsens, or becomes more painful, weepy, or spreading, stop and seek advice, as you may have a different or more severe infection needing other treatment.
Drug Interactions
Always disclose all prescription drugs, over-the-counter medicines, vitamins, and supplements to your clinician or pharmacist before starting zinc undecenoate.
Other products on the same area can affect the result or cause irritation; space them as advised and avoid unnecessary layering.
Tight, non-breathable shoes and damp socks encourage fungal growth and can reduce the benefit of treatment.
Using several antifungal products at once is rarely needed; follow your clinician's or pharmacist's advice.
Important Warnings
Keep applying zinc undecenoate for the full recommended period, including after the skin looks better, to stop the infection returning.
Keep feet clean and dry, change socks regularly, and let shoes air. Treating footwear with an antifungal powder can help prevent reinfection.
Keep the product away from the eyes and broken skin, and avoid using it on areas it is not intended for unless advised.
Use only if needed and as directed. Tell your clinician if you are pregnant or breastfeeding so suitable advice can be given.
Speak to a Clinician About Treatment
Getting advice no longer means sitting in a waiting room. Through The GP Service, you can consult with a licensed clinician in minutes — from home, on your lunch break, or wherever works for you. If treatment is clinically appropriate, your clinician can issue a prescription during the consultation. A consultation does not guarantee a prescription.
The treatment you need, when you need it.
Zinc Undecenoate FAQs
Some products are available to buy, while certain preparations are prescription-only. A licensed clinician can review your skin and prescribe where appropriate via telehealth.
Zinc undecenoate is the zinc salt of undecenoic acid and is usually combined with it. The undecenoic acid gives the main antifungal action while the zinc soothes, dries, and protects the skin.
Improvement often takes a couple of weeks, and you should keep applying it for a period after the skin looks normal to fully clear the infection and prevent recurrence.
Reinfection is common if feet stay damp or footwear is not treated. Good foot hygiene, dry socks, and aired shoes help, along with completing the full course.
Yes. Athlete's foot often starts between the toes, so apply it there as directed after drying the area thoroughly.
If your skin does not improve, worsens, or spreads, seek advice, as you may have a different infection or need a different treatment.