Coltsfoot (Tussilago farfara) is a flower in the daisy family that’s long been cultivated for its medicinal properties. However, research suggests there may be negative side effects associated with it.

Used as an herbal tea, Coltsfoot is said to treat respiratory infections, sore throats, gout, flu, and fever (1).

That said, it’s quite controversial. Research has linked some of its key components to liver damage, blood clots, and even cancer.

This article examines the potential benefits and side effects of coltsfoot, as well as its dosage recommendations.

Test-tube and animal studies link coltsfoot to several health benefits.

May reduce inflammation

Coltsfoot is often used as a natural remedy for inflammatory conditions like asthma and gout, a type of arthritis that causes swelling and joint pain.

Although research on these specific conditions is lacking, several studies indicate that coltsfoot may have anti-inflammatory properties.

One study found that tussilagone, an active component in coltsfoot, reduced several inflammatory markers in mice with drug-induced colitis, a condition characterized by intestinal inflammation (2).

In another study in mice, tussilagone helped block specific pathways involved in regulating inflammation (3).

Still, human research is needed.

Could benefit brain health

Some research suggests that coltsfoot could help protect brain health.

For example, in one test-tube study, coltsfoot extract prevented nerve cell damage and fought harmful free radicals, which are compounds that contribute to chronic disease (4).

Similarly, an animal study showed that administering coltsfoot extract to rats helped protect nerve cells, prevent tissue death in the brain, and reduce inflammation (5).

However, human studies are necessary.

May treat chronic cough

In traditional medicine, coltsfoot is often used as a natural remedy for respiratory conditions like bronchitis, asthma, and whooping cough.

Research in animals suggests that coltsfoot could be effective against chronic coughing caused by these conditions.

One animal study found that treating mice with a mixture of coltsfoot compounds helped reduce cough frequency by up to 62%, all while increasing the secretion of sputum and decreasing inflammation (6).

In another mouse study, orally administering extracts from this plant’s flower bud decreased cough frequency and increased the amount of time between coughs (7).

Despite these promising results, high-quality human studies are needed.

Summary

Animal and test-tube studies show that coltsfoot could help decrease inflammation, promote brain health, and treat chronic coughing. More research is needed to determine how it may affect health in humans.

Although coltsfoot may provide several health benefits, there are several serious concerns about its safety.

This is because coltsfoot contains pyrrolizidine alkaloids (PAs), compounds that cause acute and chronic liver damage when taken orally (8).

Several case reports tie coltsfoot-containing herbal products and supplements to serious side effects and even death.

In one study, a woman drank coltsfoot tea throughout her pregnancy, which resulted in a fatal blockage of the blood vessels leading to her newborn baby’s liver (9).

In another case, a man developed a blood clot in his lung after taking a supplement of coltsfoot and several other herbs (10).

Some PAs are also thought to be carcinogenic. In fact, senecionine and senkirkine, two PAs found in coltsfoot, have been shown to cause damage and mutations to DNA (11).

Insufficient research exists on the effects of coltsfoot itself in humans. However, one dated study noted that administering high amounts of coltsfoot to rats for a year caused 67% of them to develop a rare form of liver cancer (12).

As such, coltsfoot is listed in the Poisonous Plant Database of the Food and Drug Administration (FDA) and is even prohibited in certain countries (13).

Summary

Coltsfoot contains PAs, which are toxic compounds linked to liver damage and cancer. Many health authorities have discouraged its use.

The use of coltsfoot is not typically recommended due to its PA content and has even been banned in countries like Germany and Austria.

However, scientists have developed variations of the coltsfoot plant that are free of these harmful compounds and believed to be a safe alternative for use in herbal supplements (14).

Still, it’s best to moderate your intake to avoid any adverse effects.

If you drink coltsfoot tea, stick to 1–2 cups (240-475 ml) per day. For tinctures, be sure to use only as directed. The listed serving size for most topical products is about 1/5 tablespoon (1 ml).

Coltsfoot is not recommended for children, infants, or pregnant women.

If you have liver disease, heart problems, or other underlying health conditions, it’s best to talk to your healthcare practitioner before supplementing.

Summary

Coltsfoot is generally discouraged due to its PA content. If you do decide to use it or take varieties without these harmful compounds, be sure to moderate your intake.

Coltsfoot is a plant long used in herbal medicine to treat respiratory conditions, gout, flu, colds, and fever.

Scientific studies link it to several health benefits, including reduced inflammation, brain damage, and coughing. However, it contains several toxins and may cause serious harm, including liver damage and cancer.

Therefore, it’s best to stick to varieties that are free of PAs — or limit or avoid coltsfoot altogether — to minimize your health risks.