Xiao Yao San: Benefits, Side Effects, and Medications


Xiao Yao San is a herbal blend that has been used in Traditional Chinese Medicine (TCM) for centuries. Traditional Chinese medicine practitioners believe that Xiao Yao San removes congestion from the liver and improves the flow of qi (energy). Stagnation of liver qi is believed to affect the blood and contribute to stress / mood swings, pain, irritability, constipation, abdominal pain, premenstrual syndrome (PMS), and irregular menstrual cycles.

Xiao Yao San can be mixed by hand with the herbs themselves, but it is also sold as a dietary supplement. Although the blends may vary, the following herbs are most frequently combined in Xiao Yao San:

  • Bupleurum (hu tea)
  • Dong embankment (danggi)
  • White Peony Root (Bai Shao)
  • White attraylodes (bai zhu)
  • Poria (fuling)
  • Mint (bo he)
  • Quick fried ginger root (pao jian)
  • Licorice root (Zhigang Cao)

A variant called Jia Wei Xiao Yao San (fortified loose powder) contains the eight herbs with peony bark (mu dan pi) and gardenia fruit (zhi zi).

Also know as

  • Xiao Yao Wang (similar formula sold as teapots)
  • Free and Easy Wanderer (FAEW)
  • Relaxed tramp
  • Wandering dust

What is Xiao Yao San used for?

While there is limited scientific research on the efficacy of Xiao Yao San for therapeutic purposes, and much of what actually exists comes from animal research, there are several diseases and conditions in which the herbal blend shows promise.


An animal study published in the journal Phytotherapy Research suggests that Xiao Yao San may help alleviate depression by enhancing amino acid metabolism and altering the intestinal microflora .

The review, published in Evidence-Based Complementary and Alternative Medicine , included 26 randomized controlled trials involving 1,837 people with depression. Studies have compared Xiao Yao San to a placebo and various antidepressants, and have seen it as an adjunct to antidepressants.

The review concluded that Xiao Yao San appears to improve the efficacy of antidepressants. However, there was no significant improvement in depression with Xiao Yao Sang alone.

Contrary to these results, the study authors stated that the study was poorly designed and that more rigorous testing would be needed before Xiao Yao San could be recommended for the treatment of depression.

Post-traumatic stress disorder (PTSD)

In 2009, researchers found that Xiao Yao San reduced stress-induced anxiety behavior in rats. More recent research has linked this effect to the neurosteroid allopregnanolone, a natural hormone derived from progesterone that is believed to be a key factor in the development of PTSD.

Again, using stress-induced rats, the researchers found that Xiao Yao San not only reduced anxiety behavior, but also increased levels of allopregnanolone in the brain.

According to a 2017 study, Xiao Yao Sang's anti-inflammatory compounds, peoniflorin and isolikiritine, may be key to their beneficial effects on PTSD. Researchers have found that these compounds, which have previously been shown to alleviate depression, affect neurobiological pathways associated with PTSD symptoms.

Additionally, a 2017 study found that the mixture counteracts oxidative stress using the same mechanisms as the antidepressant Prozac (fluoxetine), a common treatment for post-traumatic stress disorder.


Research examining Xiao Yao San's effects on stress is limited to rodent studies. The stress hormone cortisol affects neurons in the hippocampus, the part of the brain responsible for concentration, memory, and mood. A study with rats found that Xiao Yao San was protected against this.


Xiao Yao San is traditionally used to calm the sour stomach. Current research shows that the herbal blend can help alleviate functional dyspepsia , more commonly known as chronic indigestion.

Xiao Yao San can help relieve stomach upset, nausea, bloating, and belching associated with indigestion, according to a review of 14 studies published in the Journal of Gastroenterology and Hepatology .

The researchers noted that the herbal drug appears to work in the same way as prokinetic drugs, drugs that increase bowel movements, such as Motilium (domperidone) and Raglan (metoclopramide).

A 2018 review of Chinese indigestion drugs also confirmed these results and suggested that Xiao Yao San was more effective than prokinetic drugs.

Possible side effects.

Xiao Yao San is considered safe and non-toxic. Reported side effects of certain herbs in the mix include:

  • Seizures (licorice root)
  • Dizziness (licorice root)
  • Edema (licorice root)
  • Headache (licorice root)
  • High blood pressure (licorice root)
  • Low blood sugar level (poria)
  • Lactation in non-lactating women (licorice root)
  • Numbness (licorice root)
  • Upset stomach (dong quai)
  • Weakness (licorice root)


Each herb in the mix is considered safe, although there are some contraindications for certain ingredients in certain doses. If you have any of the following conditions, talk to your doctor before taking Xiao Yao San:

  • Pregnancy: Dong quai can stimulate uterine contractions and should not be taken during pregnancy unless supervised by a doctor or midwife trained in TCM.
  • Cardiovascular disease: the two ingredients in Xiao Yao San are not recommended for people with cardiovascular disease: licorice root, which increases blood pressure, and porio, which has a diuretic effect.
  • Kidney Disease: Licorice root and poria are also not recommended for people with kidney disease.
  • Diabetes: Poria should not be taken at the same time as blood sugar lowering medications, such as insulin, as it can cause low blood sugar levels.

Also, licorice root is not recommended for people over the age of 65. Long-term use of the herb can cause high blood pressure and low potassium levels, potentially leading to heart and muscle problems.

Get Drug Information / Anastasia Tretyak

Selection, preparation and storage

Like Free and Easy Wanderer, Relaxed Wanderer, Xiao Yao San, and Xiao Yao Wan, the herbal blend is available in capsules, tinctures, and tea tablets (herbal extracts compressed into small pea-sized balls). They can be found in health food stores, herbal stores, and online. Tea tablets are a convenient dosage form, but may not be the ideal form according to many TCM practitioners who prefer herbal teas.

Nutritional supplements are largely unregulated and the content of any product may differ from what is stated on the product label or contain doses different from the amount indicated for each herb. Many Xiao Yao San brands list only proprietary blends or list ingredients in Chinese.

When choosing a supplement, look for products certified by ConsumerLabs, US Pharmacopeia, or NSF International.

Get the word of drug information

There is currently not enough research to support the use of Xiao Yao Sang for the treatment of any medical condition. If you are considering taking Xiao Yao San, consult your doctor. Although primary care physicians are becoming more and more familiar with herbal medicine, they may be advised to consult a licensed TCM physician.

Frequently asked questions

  • It is not clear. A study published in the journal BMC Complementary and Alternative Medicine found that Jia Wei Xiao Yao San is the most commonly prescribed herbal formula for PMS in Taiwan. However, the study authors note that there are no published studies on its safety or efficacy in treating PMS.

  • The tea tablets are swallowed whole, but because they are so small, the standard dose is usually eight tablets three times a day. Follow the manufacturer's instructions when taking tea pills or other herbal supplements.

  • There are different translations. The most common is the "dust of happiness and carelessness." Others include Leisure Dust, Free Tramp Dust, Tramp Dust, and Fun Life Dust. Note that "san" means powder and "wang" means pill, so the pill form is generally called Xiao Yao Wang.

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