What is Dang Gui Wei?

Dang Gui Wei is the thin tail of the dang gui root. Dang gui is the root of a plant in the carrot family. It is a single herb, not a mixed formula.

Chinese medicine splits this root into parts and uses each part in its own way. The body of the root is used to build blood. The tail is used to move blood and ease pain.

Herbalists use the tail for period pain, bruises and old injuries. Human trial evidence for the tail on its own is very thin. It has a long history of use, but that history is not proof that it works.

How does Dang Gui Wei work?

No one has shown how Dang Gui Wei works in the body. What follows is theory and lab work, not proof.

Lab tests find ferulic acid and ligustilide in dang gui root. In test tubes and in animals, these may widen blood vessels. They may also make platelets (the cells that form clots) less sticky.

That may be why the herb can add to the effect of blood thinners. TCM theory puts it another way. It says the tail moves blood that has become stuck.

What forms does Dang Gui Wei come in?

You will most often meet it as dried root slices, boiled into a tea.

Herb shops also sell it as a powder, as granules and as a tincture (an alcohol extract). It is nearly always mixed with other herbs by a trained herbalist.

Most products sold in shops in the West say only dong quai or dang gui. These use the whole root, not the tail.

Where it comes from:

Dang gui has been used in China for close to 2000 years.

Early texts such as the Shen Nong Ben Cao Jing list the root. Later doctors split it into three parts and gave each part its own job.

The head was said to stop bleeding. The body was said to build blood. The tail was said to move blood.

What does Dang Gui Wei help with?

• Period pain (painful periods): This is the most common reason a herbalist reaches for the tail. It is used inside multi-herb formulas, not alone. No human trial has tested the tail on its own for period pain, so treat this as traditional use only.
• Bruises and pain after a knock or injury: Chinese trauma formulas often include the tail to help move blood and settle pain. The idea comes from centuries of practice. There is no published human trial of the tail for bruising.
• Long-standing aches in the arms and legs: Herbalists add the tail to formulas for stiff, aching limbs, especially in older people. This is a traditional pattern-based use. Human evidence is missing.
• Pain that Chinese medicine calls blood stasis (blood seen as stuck): Blood stasis is a TCM idea, not a medical test result. The tail is a standard choice for it. Because the idea has no lab measure, it cannot be checked against modern trial data.
• Cold hands and feet linked in TCM to poor blood movement: Warming formulas sometimes include the tail for cold, numb fingers and toes. Lab work shows the root may relax blood vessels in animals. That is not proof of benefit in people.

Which foods are rich in Dang Gui Wei?

1. Dang gui chicken soup: Chinese home cooking simmers the whole root, not the tail, with chicken
2. Herbal soup packs from Chinese grocers: these usually hold whole root slices with other herbs

Practical Tips:

No everyday food holds the root tail, and food amounts of whole dang gui are small, but they still count if you take a blood thinner.

What are the side effects of Dang Gui Wei?

• Upset stomach or a bloated feeling
• Loose stools or diarrhoea (watery stools)
• Bruising more easily than usual
• Heavier or longer periods
• Nosebleeds or bleeding gums
• Skin rash or burning in strong sunlight (the root holds compounds that can make skin sun-sensitive)
• Allergic reaction, such as itching, rash or swelling
• Headache

Good to know:

Most people who take it inside a formula have no trouble. Stomach upset and loose stools are the usual mild complaints.

The serious risk is bleeding, and it is not mild. This matters most if you already take a blood thinner or have a bleeding problem.

Stop the herb and speak to a doctor if you bruise or bleed more than normal.

How much Dang Gui Wei should you take?

• Recommended daily: No modern research has set a dose for the tail on its own. In Chinese herbal practice, whole dang gui is usually used at about 3 to 15 grams of dried root a day. It is boiled into a tea with several other herbs. The tail is often used near the lower end, about 3 to 9 grams a day. This is a single herb that is meant to be fitted into a formula. Get your dose from a trained practitioner rather than guessing.
• Best time of day: Usually split into two doses, morning and evening. For period pain, herbalists often start it a few days before a period is due.
• With or without food: Take it with or just after food. Food lowers the chance of an upset stomach or loose stools.
• Time to effect: Not known from trials. In practice, herbalists judge period pain over one to three cycles, and pain after an injury over one to two weeks.
• How long to take it: Herbalists normally use it in short courses, often two to six weeks. Check in with your practitioner after about four weeks. If nothing has changed, there is no reason to keep taking it. Stop at least two weeks before any planned surgery or dental surgery, because of the bleeding risk.