Zynthix
Undecylenic Acid Solution · Solution · Topical
Active ingredient
Active ingredient Undecylenic Acid 25%
Purpose
Purpose Antifungal
Uses
Uses For the treatment of most athlete’s foot, jock itch, and ringworm. Relieves itching, burning, cracking, and scaling.
Warnings
Warnings For external use only. This product is not effective on the scalp. Flammable. Keep away from fire or flame. Do not use On children under 2 years of age unless directed by a doctor. For diaper rash. When using this product Avoid contact with eyes. May cause mild stinging or burning sensation on broken skin. Stop use and ask a doctor if Irritation occurs or gets worse. There is no improvement within 4 weeks (for athlete's foot and ringworm) or 2 weeks (for jock itch).
Do not use
Do not use On children under 2 years of age unless directed by a doctor. For diaper rash.
When using this product
When using this product Avoid contact with eyes. May cause mild stinging or burning sensation on broken skin.
Stop use and ask a doctor
Stop use and ask a doctor if Irritation occurs or gets worse. There is no improvement within 4 weeks (for athlete's foot and ringworm) or 2 weeks (for jock itch).
Pregnancy or breast-feeding
Pregnancy or breast feeding section If pregnant or breast-feeding, ask a health professional before use.
Keep out of reach of children
Keep out of reach of children If swallowed, get medical help or contact a Poison Control Center right away.
Directions
Directions Clean the affected area and dry thoroughly. Twist off the cap, rotate the bottom to dispense solution to the brush. Apply a thin layer to the affected area twice daily (morning and night) or as directed by a doctor. For athlete's foot: pay special attention to spaces between the toes; wear well-fitting, ventilated shoes, and change shoes and socks at least once daily. For athlete's foot and ringworm, use daily for 4 weeks. For jock itch, use daily for 2 weeks. Supervise children in the use of this product.
Inactive ingredients
Inactive ingredients Alcohol denat, Borneol, Glycerin, Isopropyl alcohol, Menthol, Water.
Questions?
Questions? 213-396-1046 / MalachiPerez291@gmail.com
Label text from the FDA structured product label by Shenzhen Siwei Yijiu Trading Co., Ltd. (revised Apr 8, 2026). Long sections are shortened; the complete label is on DailyMed.
Active ingredients
- Undecylenic Acid in 1 product
Zynthix NDC products (1)
| NDC | Strength & form | Labeler | Type |
|---|---|---|---|
| 87575-4041 | Undecylenic Acid 1 g/4mL Solution | Shenzhen Siwei Yijiu Trading Co., Ltd. | OTC MONOGRAPH DRUG |
Frequently asked questions
What is Zynthix used for?
Uses For the treatment of most athlete’s foot, jock itch, and ringworm. Relieves itching, burning, cracking, and scaling.
Who makes Zynthix?
Zynthix is listed by 1 labeler in the FDA NDC directory, including Shenzhen Siwei Yijiu Trading Co., Ltd..