What is Bai Hu Tang?

Bai Hu Tang, also known as White Tiger Decoction, is a classical Chinese herbal formula used by practitioners for high fever that comes with heavy sweating, fierce thirst and a strong, fast pulse. This document covers a single drug (a TCM formula), not an individual herb.

It is made from four ingredients: shi gao (gypsum, a calcium mineral), zhi mu (a root), gan cao (licorice root) and jing mi (plain rice). In traditional language it is described as a formula that "clears blazing heat" while protecting the body's fluids.

The honest verdict: it has a very long and respected place in Chinese medicine, but modern human trial evidence for the formula itself is thin to absent. A long history of traditional use is not proof that something works, and that applies here.

One safety point matters from the start. Bai Hu Tang contains licorice root, which can raise blood pressure, cause fluid retention and lower potassium, a mineral your heart needs to beat steadily.

How does Bai Hu Tang work?

Nobody has shown in a good human trial how Bai Hu Tang works in the body. What follows is the traditional explanation plus what laboratory work hints at.

In traditional Chinese medicine, gypsum and zhi mu are described as strongly "cold" herbs that drain burning heat from the chest and stomach. Licorice and rice are said to shield the stomach from that coldness and keep the formula from being too harsh.

That is a traditional model of the body. It is a way of matching a formula to a pattern of symptoms, not a description of measured biology.

Laboratory and animal studies of the separate ingredients suggest they may lower fever and calm inflammation (swelling and irritation in tissue). Those results come from cells and rodents. They do not show that the finished formula does the same thing in a person.

The licorice part is better understood. Glycyrrhizin, its main compound, makes the body hold on to salt and water and lose potassium, which is why the safety limits below are real rather than theoretical.

What forms does Bai Hu Tang come in?

Bai Hu Tang is most often taken as a decoction, meaning the raw ingredients are simmered in water and the liquid is drunk warm.

You may also see it as granules or a powder that dissolves in hot water, or as pills and capsules of concentrated extract. Strength varies a lot between makers, so the amount of herb in one capsule from one brand is not the same as another.

Some products are variations rather than the plain formula. Bai Hu Jia Ren Shen Tang adds ginseng, and Bai Hu Jia Gui Zhi Tang adds cinnamon twig. These are different preparations with different traditional uses.

Quality control is a real issue with imported herbal products. Some have been found to contain heavy metals or undeclared pharmaceutical drugs, so buy only from a supplier that tests its batches.

Where it comes from:

Bai Hu Tang first appears in the Shang Han Lun (Treatise on Cold Damage Disorders), written by Zhang Zhongjing around 200 CE in China.

It is one of the best known formulas in that text and has been taught continuously ever since. The name refers to the White Tiger, the traditional Chinese symbol of the west and of autumn, the season that ends summer heat.

It also entered Japanese Kampo and Korean traditional medicine, which both draw on the same classical source. Within Chinese medicine it is a staple formula for what practitioners call a "four bigs" pattern: big fever, big sweat, big thirst and a big pulse.

What does Bai Hu Tang help with?

• High fever with heavy sweating and strong thirst: This is the classic reason a TCM practitioner would choose Bai Hu Tang. The traditional picture is a fever that does not come with chills, along with drenching sweat and a craving for cold drinks. We could not find reliable human trials testing the formula against placebo for fever. A high or persistent fever needs a medical diagnosis, because the cause matters far more than the fever itself.
• Intense thirst and dry mouth during illness: Tradition treats strong thirst as a core sign pointing to this formula rather than a condition to be fixed on its own. There is no trial evidence we can cite showing it relieves thirst better than drinking fluids. Ongoing unexplained thirst can signal diabetes or dehydration and should be checked by a doctor.
• Heat exhaustion and summer heat symptoms: Practitioners have long used cooling formulas of this type for what Chinese medicine calls summer heat, with sweating, thirst and fatigue. No human trials support this use. Real heat exhaustion or heatstroke is a medical emergency and needs cooling, fluids and urgent care, not herbs.
• Toothache and swollen gums linked in TCM to 'stomach heat': Classical texts describe using this formula, often modified, when gum pain and mouth heat appear alongside thirst and a strong appetite. We found no human trial evidence for this. Dental pain usually has a physical cause such as decay or infection that only a dentist can treat.
• Red, hot, itchy skin flare-ups with heat signs: Modern TCM practice sometimes applies this formula to skin conditions such as eczema or psoriasis flares when the pattern looks hot and dry. The published research here is limited to laboratory work and small uncontrolled reports. It is not enough to say the formula helps skin disease.

Which foods are rich in Bai Hu Tang?

1. Licorice sweets and licorice tea: they contain the same compound as the gan cao in this formula, so they add to the blood pressure and potassium risk
2. Non-glutinous white rice: one of the four ingredients, used here to protect the stomach rather than as an active ingredient

Practical Tips:

If you are taking this formula, keep licorice sweets and licorice tea to a minimum so the doses do not stack up.

What are the side effects of Bai Hu Tang?

• Loose stools or diarrhoea
• Stomach discomfort or reduced appetite
• Feeling cold, chilled or weak
• Swelling in the ankles, hands or face from fluid retention (licorice)
• Raised blood pressure (licorice)
• Low potassium, which can cause muscle weakness, cramps or an irregular heartbeat (licorice)
• Headache
• Allergic rash or itching

Good to know:

Most reported problems are mild digestive ones and come from the formula's strongly cooling nature, especially if it is taken when it does not match your symptoms.

The serious risks come from the licorice root. Long or high-dose use can push blood pressure up, cause swelling and drop your potassium far enough to affect your heart rhythm.

Those effects build up over weeks rather than appearing on day one. They are a good reason to keep courses short and supervised.

How much Bai Hu Tang should you take?

• Recommended daily: There is no modern, standardised dose. Bai Hu Tang is a prescription formula and should be dosed by a trained practitioner who has assessed you. For context, classical decoction amounts per day are roughly: shi gao 30-90 g, zhi mu 9-18 g, gan cao 3-6 g and jing mi 9-15 g. The ingredients are simmered together and the liquid is split into two or three warm doses. Granule and capsule products are concentrated, so follow the label on the specific product rather than converting from raw herb weights. Do not raise the dose on your own because the licorice content limits how much is safe.
• Best time of day: Spread the daily amount over two or three doses across the day, taken warm. There is no evidence that any one time of day works better.
• With or without food: Usually taken warm between meals. If it upsets your stomach or gives you loose stools, take it shortly after food instead.
• Time to effect: Traditional practice expects a change in fever and thirst within hours to a day or two. We have no trial data to confirm that. If you are no better in 48 hours, see a doctor.
• How long to take it: This is a short-course formula for an acute problem, not a daily supplement. Traditionally it is stopped as soon as the fever and thirst settle, often within a few days. If nothing has changed after two days, stop and get a medical opinion. Because of the licorice, taking it for more than about two weeks without supervision raises the risk of raised blood pressure, swelling and low potassium (a mineral your heart needs).