Coltsfoot

Botanical name: Tussilago farfara

Parts used and where grown

The flowers, leaves, and roots of coltsfoot have been used as herbal medicines. However, the roots are generally avoided now. Coltsfoot originates in Eurasia and North Africa, and now also grows throughout damp areas of North America.

Coltsfoot has been used in connection with the following conditions (refer to the individual health concern for complete information):

Science Ratings	Health Concerns
	Cough Sore throat
Reliable and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit. For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Science Ratings

Health Concerns

Cough

Sore throat

Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars

Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star

For a herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Historical or traditional use (may or may not be supported by scientific studies)

Coltsfoot historically has been used by herbalists to alleviate coughs due to all manner of conditions. It was considered particularly useful for people with chronic coughs, such as those due to emphysema or silicosis.¹ Coltsfoot leaf was originally approved for the treatment of sore throats in the German Commission E monograph² but has since been banned in Germany for internal use.³

Active constituents

Mucilage, bitter glycosides, and tannins are considered the major constituents of coltsfoot.⁴ These are thought to give the herb anti-inflammatory and antitussive (cough prevention and treatment) activity.⁵ Coltsfoot also contains pyrrolizidine alkaloids, potentially toxic constituents.

How much is usually taken?

Internal use of coltsfoot root is not recommended due to the potential liver toxicity of its pyrrolizidine alkaloids. Tea of coltsfoot leaf or flower is made by steeping 1–2 teaspoons (5–10 grams) in 1 cup (250 ml) hot water for ten to twenty minutes.⁶ People can drink three cups (750 ml) daily. Alternatively, 1/2–1 teaspoon (2–4 ml) of tincture of the leaf or flower can be taken three times per day. Some practitioners of herbal medicine have recommended having hot coltsfoot tea ready in a thermos to drink for morning coughs due to emphysema.⁷ People should not use coltsfoot for more than one month consecutively unless on the advice of a doctor. Also, preparations guaranteed to be pyrrolizidine-free can be used indefinitely and are preferable.

Are there any side effects or interactions?

Coltsfoot contains potentially liver-damaging pyrrolizidine alkaloids, with much higher levels appearing in the root than in the leaves or the flowers. Animal studies using amounts of coltsfoot hundreds of times higher than those used as medicine have shown these alkaloids can cause cancer in animals.⁸ A single case of an baby who developed liver disease and died after the mother drank tea containing coltsfoot during pregnancy has been reported.⁹ This eventually led to the banning of coltsfoot in Germany in 1992.

Coltsfoot should not be taken during pregnancy or breast-feeding.¹⁰ Otherwise, coltsfoot is generally safe.¹¹

Coltsfoot should be differentiated from the plant called western coltsfoot (Petastites frigidus), because western coltsfoot can contain higher amounts of pyrrolizidine alkaloids. Use of western coltsfoot is not recommended.

At the time of writing, there were no well-known drug interactions with coltsfoot.

References

1. Weiss RF. Herbal Medicine. Gothenburg, Sweden: Ab Arcanum and Beaconsfield, UK: Beaconsfield Publishers Ltd, 1988, 196–7.

2. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin: American Botanical Council and Boston: Integrative Medicine Communications, 1998, 114–5.

3. Foster S. Herbal Renaissance. Salt Lake City: Gibbs-Smith Publisher, 1993, 74–8.

4. Weiss RF. Herbal Medicine. Gothenburg, Sweden: Ab Arcanum and Beaconsfield, UK: Beaconsfield Publishers Ltd., 1988, 196–7.

5. Gruenwald J, Brendler T, Jaenicke C (eds). PDR for Herbal Medicines. Montvale, NJ: Medical Economics Company, 1998, 1993–5.

6. Weiss RF. Herbal Medicine. Gothenburg, Sweden: Ab Arcanum and Beaconsfield, UK: Beaconsfield Publishers Ltd., 1988, 196–7.

7. Weiss RF. Herbal Medicine. Gothenburg, Sweden: Ab Arcanum and Beaconsfield, UK: Beaconsfield Publishers Ltd., 1988, 196–7.

8. Weiss RF. Herbal Medicine. Gothenburg, Sweden: Ab Arcanum and Beaconsfield, UK: Beaconsfield Publishers Ltd., 1988, 196–7.

9. Roulet M, Laurini R, Rivier L, Calame A. Hepatic veno-occlusive disease in newborn infant of a woman drinking herbal tea. J Pediatrics 1988;112:433–6.

10. McGuffin M, Hobbs C, Upton R, Goldberg A. American Herbal Products Association’s Botanical Safety Handbook. Boca Raton, FL: CRC Press, 1997, 117–8.

11. Weiss RF. Herbal Medicine. Gothenburg, Sweden: Ab Arcanum and Beaconsfield, UK: Beaconsfield Publishers Ltd., 1988, 196–7.

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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires August 2007.