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Limited evidenceGut health

Caprylic Acid (C8)

A medium-chain fat sold as an antifungal for candida overgrowth. It does kill Candida in a test tube, but there are no human trials showing it treats intestinal candida; its only well-documented human effect is raising ketones.

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What the science says

  • Antifungal action against Candida Limited evidence

    Laboratory work shows caprylic acid and other medium-chain fatty acids inhibit Candida albicans in vitro at fairly high concentrations. Whether an oral capsule reaches such concentrations in the gut, and whether that changes symptoms, has not been tested in humans.

  • Ketone production Moderate evidence

    A systematic review and meta-analysis of human studies confirms that C8 raises blood ketones, with the size of the rise depending strongly on how much carbohydrate is eaten alongside it. This is the best-documented effect of caprylic acid, and it has nothing to do with candida.

Dosage & safety

Studied doseNo dose has been established for candida; labels typically suggest 500–1,000 mg one to three times daily with food. Ketogenesis studies used far larger amounts, roughly 10–30 g of C8 per day.
SafetyCommonly causes nausea, cramping and loose stools, especially at higher doses and on an empty stomach. "Candida overgrowth" as a diagnosis in otherwise healthy people is not recognized; genuine invasive or oral candidiasis needs medical antifungal treatment, not a supplement.

How to take it

TimingTiming does not matter; split larger amounts across the day.
With food?With food, because on an empty stomach it commonly causes cramping and loose stools.
Worth knowingStart with one capsule a day, since the gut side effects are dose-related and show up quickly.

Frequently asked questions

Does caprylic acid kill candida in the gut?

Caprylic acid inhibits Candida albicans in a test tube at fairly high concentrations, but no human trial shows it treats intestinal candida, so the evidence is limited. Genuine candidiasis needs medical antifungal treatment.

Does caprylic acid (C8) raise ketones?

Yes, with moderate evidence: a meta-analysis confirms C8 raises blood ketones, with the rise depending strongly on how much carbohydrate you eat alongside it. Ketogenesis studies used roughly 10–30 g of C8 per day.

How much caprylic acid should I take?

No dose of caprylic acid is established for candida; labels suggest 500–1,000 mg one to three times daily with food. Start with one capsule a day, since the gut side effects are dose-related.

Does caprylic acid have side effects?

Caprylic acid commonly causes nausea, cramping and loose stools, especially at higher doses and on an empty stomach, so take it with food.

Scientific references

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