What is Du Huo?

Du Huo is a dried root used in Chinese medicine. It comes from a plant in the carrot family, Angelica pubescens. It is given for sore, stiff joints and for pain in the low back, hips and legs.

Old texts pick it out for pain that gets worse in cold, damp weather. It is almost never used on its own. The best known blend is Du Huo Ji Sheng Tang.

Long use in a tradition is not proof that a herb works. The tradition here is strong. But good human trials of Du Huo by itself are missing.

How does Du Huo work?

No one has shown how Du Huo works in people. Lab work points to plant compounds called coumarins. The main one is osthole.

In cells and in rats, osthole seems to calm swelling and dull pain signals. Whether it does the same in a person, at the dose in a cup of tea, is not known.

Chinese medicine explains it another way. It says the herb drives out "wind damp". That is the cold, wet quality thought to settle in joints.

What forms does Du Huo come in?

The usual form is dried root slices, boiled in water to make a strong tea. This is what most Chinese medicine clinics use.

You can also buy it as a loose powder, as granules that melt in hot water, in capsules, and in liquid extracts. It is also one herb inside ready-made pills such as Du Huo Ji Sheng Wan.

Where it comes from:

Du Huo turns up in Chinese medical writing from about the third century. It became a main herb for stiff, painful joints.

The formula Du Huo Ji Sheng Tang was written down in the 600s by Sun Simiao. It is still given today for low back and knee pain in older adults.

What does Du Huo help with?

• Osteoarthritis (wear-and-tear joint pain): This is the main modern use. Almost all of the research uses the multi-herb blend, not the single root. We could not find a human trial of Du Huo taken on its own.
• Low back pain: Chinese medicine treats this as a core use, mostly in people over 50. Support comes from old texts and clinic habit. No trial has tested the single root for it.
• Hip and leg pain: Old texts say Du Huo works on pain in the lower half of the body. This is a rule of thumb from the tradition, not a lab finding.
• Joint pain that flares in cold, damp weather: Texts name this as the pattern the herb suits best. There is no test that can check this pattern. No study has looked at whether weather changes the result.
• Stiff, sore neck with headache: A smaller traditional use, usually as part of a blend. Nothing here has been tested in people.

What are the side effects of Du Huo?

• Upset stomach or nausea (feeling sick)
• Loose stools
• Dry mouth
• Skin that burns faster in the sun
• Rash or itchy skin, rarely
• Dizziness at high doses

Good to know:

Most people take Du Huo with no trouble. When side effects show up, they are mild. They tend to fade once you stop the herb.

The one to watch is sun. The root holds compounds that make skin burn faster. Cover up or use sun cream on bright days.

Quality is a real risk too. Roots get mixed up or swapped in trade. Buy from a seller who tests what they sell.

How much Du Huo should you take?

• Recommended daily: In a boiled tea, the usual amount is 3 to 9 grams of dried root a day. Some texts go up to 12 grams. Capsules, granules and extracts vary a lot in strength, so follow the label or ask your practitioner.
• Best time of day: Split the daily amount into two doses, one in the morning and one in the evening.
• With or without food: Take it after food. That lowers the chance of an upset stomach.
• Time to effect: This has not been measured well. Traditional practice expects some change within one to two weeks.
• How long to take it: Short courses are normal, often two to six weeks. Check how you feel at four weeks. If nothing has changed, stop it and talk to a doctor or practitioner.