What is Grindelia?

Grindelia is a sticky yellow flower in the daisy family. Herbalists use the dried flower buds and leaves for coughs that bring up thick mucus. It is also put on the skin for the rash from poison ivy and poison oak.

The Latin name is Grindelia robusta. Other names are gumweed, tarweed and rosinweed. The buds give off a sticky gum, and that is how it got its name.

Here is the short verdict. Grindelia has a long record of use in Western herbal medicine, but no human trials support it. A long history of use is not proof that a herb works, so read the rest of this page with that in mind.

How does Grindelia work?

No one has shown how Grindelia works in people. The ideas below come from lab work and from what old herbal books report.

The herb is rich in resins (sticky plant gums) and saponins (soap-like plant compounds). Both can thin mucus and make a cough looser and more productive. Saponins may also make the airway lining produce more watery fluid.

Lab tests suggest some parts of the plant relax smooth muscle, the muscle that rings the airways. This has not been tested in people, so it stays a theory.

What forms does Grindelia come in?

The most common forms are a tincture (an alcohol extract) and a liquid extract. Both are made from the dried flower buds and leaves.

You can also find the loose dried herb for tea, plus cough syrups and lozenges that list it as one of several herbs. Skin washes and creams are sold for itchy rashes.

The sticky resin does not dissolve well in water. That is why most makers use alcohol rather than plain tea.

Where it comes from:

Indigenous peoples of western North America used gumweed for chest complaints and for skin rashes. Settlers and doctors picked up the practice in the 1800s.

Eclectic physicians in the United States made it a standard cough remedy. It was listed in the United States Pharmacopeia from 1882 to 1926, then moved into European herbal use. Germany's Commission E later listed it for cough and bronchitis (swelling in the airways) on the strength of that record.

What does Grindelia help with?

• Cough with thick mucus: This is the main use, and it rests on tradition rather than trials. Western herbalists give Grindelia when a cough is tight and the mucus is hard to bring up. No human study has tested whether it helps.
• Bronchitis (swelling and mucus in the airways): German Commission E listed Grindelia for bronchitis based on its long use and its resin content. That listing reflects expert opinion and history, not trial results. Treat a chest infection that is getting worse as a job for a doctor.
• Mild asthma symptoms, as an add-on only: Old herbal texts used Grindelia for wheezing. Lab work hints that it may relax airway muscle, but this has never been shown in people. It is not a rescue treatment and cannot stand in for an inhaler.
• Whooping cough (a severe coughing illness), historic use: Nineteenth-century doctors used it for this. Whooping cough is now a vaccine-preventable illness that needs medical care, and self-treating it is not safe.
• Poison ivy and poison oak rash, used on the skin: A wash or cream made from the herb was a common frontier remedy for the itch. Reports are all from case notes and old texts. Some people with daisy-family allergy get a rash from the herb itself.

Which foods are rich in Grindelia?

You will only meet this herb in a tea, tincture, syrup or skin cream.

What are the side effects of Grindelia?

• Upset stomach, nausea or cramping
• Diarrhoea
• A burning or bitter feeling in the mouth and throat
• Skin rash or itching, mainly in people allergic to daisy-family plants
• Kidney irritation with large doses or long use
• Slow, irregular or unusually forceful heartbeat with very large doses

Good to know:

Most people who take normal amounts for a short time have no trouble. Stomach upset is the complaint that comes up most often.

The serious effects are tied to large doses or long use. Because the resins leave the body through the kidneys, high doses can irritate them. Very large doses have been reported to affect heart rhythm (the beat and pace of the heart).

Stop taking it and get advice if you notice a rash, less urine than usual, or a heartbeat that feels wrong.

How much Grindelia should you take?

• Recommended daily: There is no officially proven dose. The amounts below come from herbal texts and from the German Commission E listing. Dried herb: about 4 to 6 grams a day, split into two or three servings as a tea. Tincture (an alcohol extract, usually 1:5): about 1 to 2 mL, up to three times a day. Do not go above these amounts. Larger doses have been linked to stomach and kidney irritation.
• Best time of day: Spread doses through the day while the cough is active. Many people take one dose in the evening, since a tight cough often feels worse at night.
• With or without food: Take it with food or just after a meal. The resins can upset an empty stomach.
• Time to effect: Nobody has measured this properly. Traditional use suggests any loosening of a cough would show within a few days, not weeks.
• How long to take it: Keep it short. Most herbalists use it for a week or two while a cough clears. If your cough has not improved after 7 days, stop and see a doctor. Do not take it for more than 2 to 3 weeks without medical advice.