Antifungal
Undecylenic Acid
Also known as: 10-Undecenoic Acid, Undecenoic Acid, Undecylenic acid, 10-Undecenoic acid
Natural antifungal fatty acid derived from castor oil. Used to support healthy gut flora and combat candida overgrowth.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every Undecylenic Acid product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Thorne Undecylenic Acid | 86 A- | $0.54 |
| 2 | Pure Encapsulations A.C. Formula II | 81 A- | $0.75 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much Undecylenic Acid should I take?
The typical range is 150-500 mg daily. 2-4 weeks typical course
When should I take Undecylenic Acid?
With meals. Yes.
Which form of Undecylenic Acid is best?
Calcium undecylenate — Common supplemental form. Other forms in the catalog: Free acid.
Is Undecylenic Acid safe?
Commonly reported: GI upset at high doses. Serious warnings: None known. No known issues
Which Undecylenic Acid supplement scores highest?
Thorne Undecylenic Acid, at 86/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Antifungal support
- Candida overgrowth
- Gut health
How it works
- Disrupts fungal cell membranes
- Inhibits fungal growth
Dosage
- Typical range
- 150-500 mg daily
- Timing
- With meals
- With food
- Yes
- Duration
- 2-4 weeks typical course
- Special populations
- Generally safe for adults
Forms
- Calcium undecylenate
- Free acid
Safety
Common side effects
- GI upset at high doses
Contraindications
- None known
Products containing Undecylenic Acid
Top-scoring supplements in our catalog that list Undecylenic Acid on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Traditional use with limited clinical trials
Grade C: Mostly observational or small trials; mechanism is plausible but unproven at scale.
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.