Limited evidenceImmunity

Horseradish Root

Horseradish root, usually combined with nasturtium, is a licensed herbal remedy in Germany for airway and urinary infections. The clinical support is one open trial plus laboratory work, not a solid trial programme.

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What the science says

Acute bronchitis Limited evidence
A clinical study of a Tropaeolum majus plus Armoracia rusticana combination reported symptom improvement in acute bronchitis. The design was not a rigorous double-blind placebo comparison, so the size of the true effect is uncertain.
Antibacterial activity Limited evidence
The mustard oils (isothiocyanates) in horseradish inhibit bacteria including established biofilms in laboratory studies, and a pharmacology review summarises this activity. Whether enough reaches the urinary tract in people to treat an infection is unproven.

Dosage & safety

Studied doseThe German combination product supplies roughly 200 mg nasturtium herb plus 80 mg horseradish root per tablet, taken 3–5 times daily. Standalone horseradish supplements are not standardized.

SafetyIrritating to the stomach at higher doses, causing heartburn, nausea and mouth or skin irritation. Avoid with gastric or duodenal ulcers and with kidney disease, and in children under 4. It is not a replacement for antibiotics in a diagnosed urinary infection.

How to take it

TimingSpread through the day, three to five times daily as the tested product is dosed.

With food?Always with food — horseradish is harsh on an empty stomach and causes heartburn and nausea.

Worth knowingThe evidence is for the German nasturtium-plus-horseradish combination tablet, not for standalone horseradish capsules, which are not standardized at all.

Frequently asked questions

Does horseradish help bronchitis or urinary infections?

The evidence for horseradish is limited: one non-rigorous clinical study of a nasturtium-plus-horseradish combination reported symptom improvement in acute bronchitis. Its antibacterial mustard oils work in the lab, but it is unproven that enough reaches the urinary tract to treat an infection.

How much horseradish root should I take?

The German combination product supplies roughly 200 mg nasturtium herb plus 80 mg horseradish root per tablet, taken 3–5 times daily with food. Standalone horseradish supplements are not standardized.

Can horseradish replace antibiotics for a UTI?

No. Horseradish root is not a replacement for antibiotics in a diagnosed urinary infection, and its antibacterial activity is shown only in laboratory studies.

Does horseradish have side effects?

At higher doses horseradish causes heartburn, nausea and mouth or skin irritation, so always take it with food. Avoid it with gastric or duodenal ulcers, kidney disease, and in children under 4.

Scientific references

A combination of Tropaeolum majus herb and Armoracia rusticana root for the treatment of acute bronchitis
Albrecht U, Stefenelli U, Stange R — Phytomedicine, 2023
Natural isothiocyanates express antimicrobial activity against developing and mature biofilms of Pseudomonas aeruginosa
Kaiser SJ, Mutters NT, Blessing B — Fitoterapia, 2017
Isothiocyanates in medicine: A comprehensive review on phenylethyl-, allyl-, and benzyl-isothiocyanates
Hoch CC, Shoykhet M, Weiser T — Pharmacol Res, 2024

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Herbal medicines: what the evidence says (335)