What Is Coltsfoot?

Coltsfoot is a perennial plant that can grow up to 12 inches tall. The plant has golden-colored flowers that resemble dandelions. Coltsfoot originated in Europe and parts of Asia. The plant also grows throughout damp areas of North America and is known to flourish along roadsides and in meadows and hedgerows. 

Coltsfoot has been used as an herbal supplement in traditional Chinese medicine (TCM) and Western herbalism, primarily as a treatment for sore throat and chronic (long-term) coughs and other respiratory diseases.

Coltsfoot's latin name, Tussilago farfara, is derived from the word "tussis," meaning cough, and "ago," meaning "to act on."

Uses of Coltsfoot

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease. 

Coltsfoot is often mistaken for the dandelion plant. The flowers and leaves are the primary parts of the plant that are used for medicinal purposes, and the roots are usually avoided.

Coltsfoot has been used in TCM as an antioxidant (to strengthen the immune system), an antitussive (to ease cough), an antimicrobial (to kill bacteria), and an anti-inflammatory agent (to lower inflammation). However, most studies involving coltsfoot have been done on animals and not on humans. There is not enough evidence to support the use of coltsfoot for these actions in humans.

Additionally, the safety of coltsfoot taken orally has been questioned due to the presence of hepatotoxic pyrrolizidine alkaloids (PAs). PAs can severely damage the liver and lungs.

What Are the Side Effects of Coltsfoot?

Many side effect concerns are with oral use of coltsfoot due to its PA content. The primary side effect reported from this use of coltsfoot is liver toxicity. Other possible side effects include:

• Carcinogenicity: A substance that promotes carcinogenesis (the formation of cancer)
• Mutagenicity: A chemical or physical agent's capacity to cause mutations (genetic alterations), which is what is linked to the carcinogenesis of PAs
• Sun sensitivity: Making you more susceptible to sunburn and sun damage of the skin
• Allergic reactions: Hives, skin rash, swelling, wheezing, shortness of breath, or more serious signs and symptoms like nausea and vomiting, severe trouble breathing, weak pulse, seizures, or loss of consciousness

Always consult your healthcare provider first about supplement use.

Precautions

Coltsfoot is not generally considered safe for anyone. However, the herb should be especially avoided in the following populations:

• Infants or children
• Pregnant people
• Breastfeeding people
• Those with liver problems
• People with allergies to ragweed, chrysanthemums, marigolds, daisies, or related plants in the Asteraceae (Compositae) family
• Individuals with high blood pressure as coltsfoot may interfere with treatment
• People with heart disease
• People with bleeding disorders
  

Dosage: How Much Coltsfoot Should I Take?

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs. 

There is insufficient clinical research data to support a recommended safe dosage of coltsfoot. The appropriate dose of any supplement, including coltsfoot, should be based on several factors such as weight, age, general health, and other factors.

Although herbal products may be natural, that doesn't mean they are necessarily safe, particularly when taken in large doses.

What Happens If I Take Too Much Coltsfoot?

Taking too much coltsfoot may lead to liver damage and increase the risk of certain cancers.

A study examined the toxic effects of plants containing PAs. The study reported that the toxic effects of some herbs—including coltsfoot—can cause acute liver disease, resulting in veno-occlusive disease (characterized by an enlarged liver) or, in some instances, liver cirrhosis. Cirrhosis is a serious condition in which the liver no longer functions properly due to long-term damage.

The study also explains that some PAs, including those in coltsfoot, have shown genotoxic (causing genetic damage), mutagenic (causing gene mutations), teratogenic (affecting the normal development of the fetus in utero), and carcinogenic (cancer-causing) effects.

The PA in coltsfoot has also reportedly caused veno-occlusive disease (a condition involving liver enlargement), which was reported in a newborn after the infant’s mother drank tea containing coltsfoot during pregnancy. The liver condition was said to result from the well-known hepatotoxins (substances that are toxic to the liver) contained in coltsfoot.

Interactions

There are no well-documented cases of coltsfoot interacting with other drugs or supplements.

Coltsfoot may increase blood-clotting time and cause a higher risk of bruising and bleeding when taken with anticoagulants, such as Jantoven (warfarin) or aspirin.

Anyone taking these or any other medications, supplements, or over-the-counter (OTC) drugs or preparations should consult their healthcare provider before taking herbal products.

It is essential to carefully read the ingredients list and nutrition facts panel of a supplement to learn which ingredients and how much of each ingredient is included. Please review this supplement label with your healthcare provider to discuss any potential interactions with foods, other supplements, and medications.

How to Store Coltsfoot

If you have coltsfoot in your home, store it as directed on the packaging and ensure it is out of the reach of children and pets.

Sources of Coltsfoot & What to Look For

Coltsfoot is commonly made into tea using the leaves or flowers of the plant. Other preparations include a topical flower compress to treat skin problems such as inflammation.

Some people smoke the herb, suggesting that it is effective for respiratory disorders, but the evidence does not back up the safety or efficacy of smoking coltsfoot. In addition, the safe and effective use of coltsfoot in tea or to treat skin problems is not backed up by scientific evidence.

Herbal supplements are not regulated as strictly as conventional drugs and food products in the United States. Therefore, you must do your due diligence to ensure you get a safe, hepatotoxic PA-free product.

Dietary supplements sold in the United States are not required to state the amount of PAs they may contain. You should assume there are hepatotoxic PAs in any coltsfoot product unless stated otherwise. Avoid using coltsfoot products that are not certified and labeled as hepatotoxic PA-free.

Summary

Coltsfoot, also known as Tussilago farfara, is an herbal supplement marketed for antitussive, antimicrobial, and anti-inflammatory properties. However, limited human studies assessing the safety and efficacy of coltsfoot are available. Coltsfoot use also carries the risk of liver toxicity due to pyrrolizidine alkaloids in its products.

The potential risks of coltsfoot outweigh the purported benefits. Always consult a healthcare provider before taking coltsfoot or any other herbal supplement.