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Active ingredient

Manufacturer
Shenzhen Siwei Yijiu Trading Co., Ltd. | Nanjing Ningjitong Pharmaceutical Biotechnology Co., Ltd
Effective date
2026-04-08
Label type
HUMAN OTC DRUG LABEL
Version
1
Source
full-release
Hydrated at
2026-06-01 01:53:00

Label at a glance#

ProductZYNTHIX
Active ingredientUNDECYLENIC ACID
Label structure11 sections

Indications and uses

For the treatment of most athlete’s foot, jock itch, and ringworm. Relieves itching, burning, cracking, and scaling.

Dosage and administration

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...

Label contents#

Full prescribing information#

Active ingredient

OTC - ACTIVE INGREDIENT SECTION

Undecylenic Acid 25%

Purpose

OTC - PURPOSE SECTION

Antifungal

Uses

INDICATIONS & USAGE SECTION

  • For the treatment of most athlete’s foot, jock itch, and ringworm.
  • Relieves itching, burning, cracking, and scaling.

Warnings

WARNINGS SECTION

  • For external use only.
  • This product is not effective on the scalp.
  • Flammable. Keep away from fire or flame.

Do not use

OTC - DO NOT USE SECTION

  • On children under 2 years of age unless directed by a doctor.
  • For diaper rash.

When using this product

OTC - WHEN USING SECTION

  • Avoid contact with eyes.
  • May cause mild stinging or burning sensation on broken skin.

Stop use and ask a doctor if

OTC - STOP USE SECTION

  • 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 section

OTC - PREGNANCY OR BREAST FEEDING SECTION

If pregnant or breast-feeding, ask a health professional before use.

Keep out of reach of children

OTC - KEEP OUT OF REACH OF CHILDREN SECTION

If swallowed, get medical help or contact a Poison Control Center right away.

Directions

DOSAGE & ADMINISTRATION SECTION

  • 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.

Other information

OTHER SAFETY INFORMATION

  • Store at room temperature 15°-30°C (59°-86°F).
  • Protect from excessive heat and direct sunlight.

Inactive ingredients

INACTIVE INGREDIENT SECTION

Alcohol denat, Borneol, Glycerin, Isopropyl alcohol, Menthol, Water.

Questions?

OTC - QUESTIONS SECTION

213-396-1046 / MalachiPerez291@gmail.com

Box Front Panel

PACKAGE LABEL.PRINCIPAL DISPLAY PANEL

ZYNTHIX
ANTIFUNGAL PEN

25% Undecylenic Acid
Maximum Strength

  • Helps Treat Fungal Infections
  • Relieves Itching & Burning
  • Supports Healthy Nails

NET:12ml/0.42fl.oz
(3x4mL)

Product PackagingProduct Packaging

DailyMed RxNorm Mappings#

RxCUI, RxNorm string, TTY table
RxCUIRxNorm stringTTYSPL version
998329undecylenic acid 25 % Topical SolutionPSN1
998329undecylenic acid 250 MG/ML Topical SolutionSCD1
998329undecylenic acid 25 % Topical SolutionSY1

DailyMed Product Concepts#

Product concept, Relation, Version table
Product conceptRelationVersionEffective
6c13b22c-b3ba-4127-b768-0132dd5ab0d1Product name120230829

DailyMed Package Descriptions#

Package NDC, Product, Description table
Package NDCProductDescriptionFormQuantityStrengthSPL version
87575-4041-1ZYNTHIX4 mL in 1 APPLICATORSOLUTION41
87575-4041-1ZYNTHIX3 in 1 BOXSOLUTION31

Products#

Every source-derived product name is available through these pages.

DailyMed product names page 1 of 1 · 9 matching rows.

NDC Codes#

Product NDC, Package NDC table
Product NDCPackage NDC
87575-404187575-4041-1

Ingredients#

Every source-derived ingredient row is available through these pages.

DailyMed ingredient rows page 1 of 1 · 7 matching rows.

Name, UNII, Kind table
NameUNIIKind
UNDECYLENIC ACIDK3D86KJ24NACTIB
MENTHOLL7T10EIP3AIACT
BORNEOLM89NIB437XIACT
ALCOHOL3K9958V90MIACT
ISOPROPYL ALCOHOLND2M416302IACT
GLYCERINPDC6A3C0OXIACT
WATER059QF0KO0RIACT

Source Document#

Source XML

openFDA label cross-check#

OpenFDA label data provides additional search and identifier links. DailyMed’s Structured Product Label is the canonical label on FDA.report. Matching records are deduplicated before they are shown below.

Matched openFDA labels page 1 of 1 · 1 matching rows.

Brand, Generic, Manufacturer table
BrandGenericManufacturerSPL set IDEffective dateAvailable safety fieldsJoin
ZYNTHIXUNDECYLENIC ACID SOLUTIONShenzhen Siwei Yijiu Trading Co., Ltd.4ef4a167-f673-efb4-e063-6294a90a30262026-04-08WarningsExact identifier
ndc (package): 87575-4041-1
ndc (product): 87575-4041
ndc11 (package): 87575404101
spl id: 4ef4a167-f674-efb4-e063-6294a90a3026
spl set id: 4ef4a167-f673-efb4-e063-6294a90a3026

Reported adverse events (FAERS/openFDA)#

Adverse event summaries are temporarily unavailable. Other product information remains available.