Ingredient 1 of 6
Undecylenic Acid in Nail Defender
Learn where this castor oil fatty acid comes from, why it leads the label and how it fits the daily spray routine.*

- Group
- Fatty acid
- Source
- Castor bean oil
- Position
- First on the label
- Brand focus
- Purifying, skin balance*
The short version
Undecylenic acid is the first ingredient on the Nail Defender label. It is a fatty acid made from castor oil, and the brand includes it for its purifying qualities and its role in supporting a healthy skin balance around the nail.*
Where it comes from
Castor plants grow in warm parts of the world. Their beans are pressed to make castor oil, a thick oil that has been used in personal care for a very long time. When castor oil is heated and broken down, one of the results is undecylenic acid. So while the name sounds technical, its roots are in a plant.
Why it leads the label
Ingredients are usually listed starting with the main one. Putting undecylenic acid first tells you it is the backbone of the formula. The rest of the label builds around it: clove oil adds a fresh plant note, and the moisturizing oils help the spray feel gentle.*
How it fits your routine
You do not need to do anything special. Each spray of Nail Defender carries undecylenic acid along with the other five names. Spray onto clean, dry nails once or twice a day and let it absorb. The steps are on our how to use page.
Tip: Clean, dry nails give each spray the best start. Pat dry between the toes too.
Want the full story?
Our journal post From Castor Bean to Nail Spray follows this ingredient from the field to the bottle.
Other names on the label

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