Home > Herb database > Shan Yao

Yam

Chinese: 山药

Pinyin: Shān Yào

Parts used: Dried rhizome

TCM category: Tonic herbs for Qi Deficiency

TCM nature: Neutral

TCM taste(s): Sweet

Organ affinity: Spleen Kidney Lung

Scientific name: Dioscorea opposita

Other names: Chinese yam, Cinnamon vine, Nagaimo, Chinese potato, Japanese mountain yam, Korean yam

Use of yam (Shan Yao) in TCM

Please note that you should never self-prescribe TCM ingredients. A TCM ingredient is almost never eaten on its own but as part of a formula containing several ingredients that act together. Please consult a professional TCM practitioner, they will be best able to guide you.

Preparation: Remove impurities, wash, cut and dry.

Dosage: 3-6g.

Main actions according to TCM*: Tonifies the Spleen and Stomach. Tonifies the Lung Qi and nourishes the Lung Yin. Nourishes the Kidneys and consolidates Jing.

Primary conditions or symptoms for which yam may be prescribed by TCM doctors*: Vaginal discharge Diarrhea Spermatorrhea Urinary incontinence Uterine prolapse Whooping cough

Contraindications*: This herb should be used with caution when there is Excess Heat or Dampness, especially Dampness in the abdomen.

Common TCM formulas in which yam (Shan Yao) are used*

Wan Dai Tang

Source date: 1826 AD

Number of ingredients: 10 herbs

Formula key actions: Tonifies the Middle Burner. Removes Dampness. Stops vaginal discharge. Strengthens the Spleen.

Conditions targeted*: PreeclampsiaOtitis media and others

Shan Yao is a king ingredient in Wan Dai Tang. Like the name indicates, it means it has more power than other ingredients in the formula.

In Wan Dai Tang, Shan Yao strengthens the Spleen, tonifies Qi, removes Dampness, and builds up the Essence. It works collaboratively with Bai Zhu to support the Girdle Vessel in securing the Channels.

Read more about Wan Dai Tang

Yi Huang Tang

Source date: 1826 AD

Number of ingredients: 5 herbs

Formula key actions: Strengthens the Spleen. Dries Dampness. Clears Heat. Stops vaginal discharge.

Conditions targeted*: CervicitisCervical erosion and others

Shan Yao is a king ingredient in Yi Huang Tang. Like the name indicates, it means it has more power than other ingredients in the formula.

In Yi Huang Tang, Shan Yao strengthens the Spleen and stabilizes the Penetrating Vessel and the Essence. It also works together with Qian Shi (Foxnut seeds) to tonify the Directing Vessel Deficiency. The 2 herbs are also able to support Body Fluids metabolism.

Read more about Yi Huang Tang

Liu Wei Di Huang Wan

Source date: 1119 AD

Number of ingredients: 6 herbs

Formula key actions: Nutritive tonic for the Liver and Kidney Yin Essence (nourishes the parasympathetic nervous system).

Conditions targeted*: Chronic nephritisProstate diseases and others

Shan Yao is a deputy ingredient in Liu Wei Di Huang Wan. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Liu Wei Di Huang Wan, Shan Yao stabilizes the Essence by tonifying the Spleen. Indeed, to reinforce Essence and improve its function, the Spleen (the source of postnatal Essence) must function properly.

Read more about Liu Wei Di Huang Wan

Ba Wei Di Huang Wan

Source date: 220 AD

Number of ingredients: 8 herbs

Formula key actions: Tonifies Yang. Warms the Kidneys and lower extremities.

Conditions targeted*: Diabetes mellitusDiabetes insipidus and others

Shan Yao is a deputy ingredient in Ba Wei Di Huang Wan. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Ba Wei Di Huang Wan, Shan Yao stabilizes the Essence by tonifying the Spleen. Indeed, to reinforce Essence and improve its function, the Spleen (the source of postnatal Essence) must function properly.

Read more about Ba Wei Di Huang Wan

You Gui Wan

Source date: 1624 AD

Number of ingredients: 10 herbs

Formula key actions: Warms and tonifies Kidney Yang. Replenishes the Essence. Tonifies the Blood.

Conditions targeted*: Nephrotic syndromeOsteoporosis and others

Shan Yao is a deputy ingredient in You Gui Wan. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

Read more about You Gui Wan

Qi Ju Di Huang Wan

Source date: 1350 AD

Number of ingredients: 8 herbs

Formula key actions: Nourishes Kidney and Liver Yin. Improves vision.

Conditions targeted*: Diabetes mellitusDiabetes insipidus and others

Shan Yao is a deputy ingredient in Qi Ju Di Huang Wan. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Qi Ju Di Huang Wan, Shan Yao stabilizes the Essence by tonifying the Spleen. Indeed, to reinforce Essence and improve its function, the Spleen (the source of postnatal Essence) must function properly.

Read more about Qi Ju Di Huang Wan

Zuo Gui Wan

Source date: 1624 AD

Number of ingredients: 8 herbs

Formula key actions: Nourishes the Yin. Strengthens the Kidneys. Fills the Essence. Augments the marrow.

Conditions targeted*: Chronic bronchitisChronic nephritis and others

Shan Yao is a deputy ingredient in Zuo Gui Wan. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Zuo Gui Wan, Shan Yao benefits the Yin and tonifies the Spleen which is the origin of the postnatal Qi and Blood

Read more about Zuo Gui Wan

Zuo Gui Yin

Source date: 1624 AD

Number of ingredients: 6 herbs

Formula key actions: Nourishes the Yin. Tonifies the Kidneys.

Shan Yao is a deputy ingredient in Zuo Gui Yin. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Zuo Gui Yin, Shan Yao benefits the Yin and tonifies the Spleen which is the origin of the postnatal Qi and Blood

Read more about Zuo Gui Yin

Zhi Bo Di Huang Wan

Source date: 1584 AD

Number of ingredients: 8 herbs

Formula key actions: Tonifies Yin. Drains Fire.

Shan Yao is a deputy ingredient in Zhi Bo Di Huang Wan. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Zhi Bo Di Huang Wan, Shan Yao stabilizes the Essence by tonifying the Spleen. Indeed, to reinforce Essence and improve its function, the Spleen (the source of postnatal Essence) must function properly.

Read more about Zhi Bo Di Huang Wan

Ba Xian Chang Shou Wan

Source date: 1615 AD

Number of ingredients: 8 herbs

Formula key actions: Treats Yin Deficiency of the Lungs and Kidneys.

Shan Yao is a deputy ingredient in Ba Xian Chang Shou Wan. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Ba Xian Chang Shou Wan, Shan Yao stabilizes the Essence by tonifying the Spleen. Indeed, to reinforce Essence and improve its function, the Spleen (the source of postnatal Essence) must function properly.

Read more about Ba Xian Chang Shou Wan

Shen Ling Bai Zhu San

Source date: 1107 AD

Number of ingredients: 10 herbs

Formula key actions: Augments the Qi. Strengthens the Spleen. Leaches out Dampness. Stops diarrhea.

Conditions targeted*: Chronic gastritisEnteritis and others

Shan Yao is a deputy ingredient in Shen Ling Bai Zhu San. This means it helps the king ingredient(s) treat the main pattern or it serves to treat a coexisting pattern.

In Shen Ling Bai Zhu San, Shan Yao tonifies the Spleen and supports the key herbs.

Read more about Shen Ling Bai Zhu San

Suo Quan Wan

Source date: 1227 AD

Number of ingredients: 3 herbs

Formula key actions: Warms the Kidneys. Dispels cold. Reduces urinary frequency. Stops leakage.

Conditions targeted*: Urinary incontinencePostpartum incontinence and others

Shan Yao is an assistant ingredient in Suo Quan Wan. This means that it either serves to reinforces the effect of other ingredients or it moderates their toxicity.

In Suo Quan Wan, Shan Yao strengthens the Spleen, tonifies the Kidneys, and binds up the Essence.

Read more about Suo Quan Wan

Fu Tu Dan

Source date: 1107 AD

Number of ingredients: 5 herbs

Formula key actions: Stabilizes the Kidney Qi. Strengthens the Spleen. Stops leakage.

Read more about Fu Tu Dan

Wen Qi Hua Shi Tang

Source date: 1827 AD

Number of ingredients: 7 herbs

Formula key actions: Supports Kidney Yang. Supplies Spleen Qi. Expels Cold and Dampness from the Uterus.

In Wen Qi Hua Shi Tang, Shan Yao protects the Penetrating Vessel (Chong Mai)

Read more about Wen Qi Hua Shi Tang

Tiao Gan Tang

Source date: 1827 AD

Number of ingredients: 7 herbs

Formula key actions: Nourishes Kidney and Liver Yin.

In Tiao Gan Tang, Shan Yao tonifies Stomach and Kidneys

Read more about Tiao Gan Tang

Gui Shao Di Huang Tang

Source date: 1706 AD

Number of ingredients: 8 herbs

Formula key actions: Nourishes Blood. Nourishes Yin.

In Gui Shao Di Huang Tang, Shan Yao nourishes Liver and Kidney Yin

Read more about Gui Shao Di Huang Tang

Da Bu Yuan Jian

Source date: 1624 AD

Number of ingredients: 8 herbs

Formula key actions: Tonifies Yin and Blood. Nourishes Qi and Yang.

Conditions targeted*: Uterine prolapse and others

In Da Bu Yuan Jian, Shan Yao benefits the Yin and tonifies the Spleen which is the source of the postnatal constitution.

Read more about Da Bu Yuan Jian

Shen Qi Wan

Source date: 220 AD

Number of ingredients: 8 herbs

Formula key actions: Tonifies and warms Kidney Yang.

Conditions targeted*: Diabetes mellitusHyperaldosteronism and others

In Shen Qi Wan, Shan Yao is Sweet and bland. It stabilizes the Essence by tonifying the Spleen. To reinforce the Essence and improve its function, the Spleen which is the source of postnatal Essence, must function properly. It is effective in treating Deficiency and various consumptive patterns.

Read more about Shen Qi Wan

Ren Shen Zi Xie Tang

Source date: 1602 AD

Number of ingredients: 7 herbs

Formula key actions: Tonifies Blood.

In Ren Shen Zi Xie Tang, Shan Yao tonifies Qi in order to nourish Blood

Read more about Ren Shen Zi Xie Tang

Dang Gui Di Huang Yin

Source date: 1640 AD

Number of ingredients: 7 herbs

Formula key actions: Nourishes Blood. Tonifies Kidney and Liver Yin. Regulates the menstrual cycle.

In Dang Gui Di Huang Yin, Shan Yao stabilizes the Essence by tonifying the Spleen. Indeed, to reinforce Essence and improve its function, the Spleen (the source of postnatal Essence) must function properly.

Read more about Dang Gui Di Huang Yin

Key TCM concepts behind yam (Shan Yao)'s properties

In Traditional Chinese Medicine (TCM), yam are plants that belong to the 'Tonic herbs for Qi Deficiency' category. Tonic herbs are used for patterns of Deficiency, when one lacks one of the 'Four Treasures' (Qi, Blood, Yin and Yang). Qi tonics are typically sweet and they tend to enter the Spleen and Lungs because these Organs are most involved with the production of Qi.

Furthermore yam are plants that are Neutral in nature. This means that yam typically don't affect the balance in your body. Balance between Yin and Yang is a key health concept in TCM. Eating too many "Hot" (Yang) ingredients can lead to an imbalance whereby one has a Yang Excess. The inverse is true as well: too many "Cold" (Yin) ingredients can lead to a Yin Excess. The Neutral nature of yam means that you don't have to worry about that!

Yam also taste Sweet. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Sweet ingredients like yam tend to slow down acute reactions and detoxify the body. They also have a tonic effect because they replenish Qi and Blood.

The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such yam are thought to target the Spleen, the Kidney and the Lung. In TCM the Spleen assists with digestion, Blood coagulation and Fluids metabolism in the body. The Kidneys do not only regulate the urinary system but also play a key role in the reproductive system and the growth and aging process of the body. In addition to performing respiration, the Lungs are thought in TCM to be a key part of the production chain for Qi and the Body Fluids that nourish the body.

Research on yam (Shan Yao)

A mixture consisting of Rhizoma Dioscoreae has a good nutritional and health promoting effect on pregnancy.1

Sources:

1. Ling CD, Zhang ZJ, Chen ZL. (1996). Studies on nutritional effects of traditional Chinese tonics with strengthened nutrients on pregnant women and rats. Zhongguo Zhong Xi Yi Jie He Za Zhi. , 16(5):270-3.

Use of yam (Shan Yao) as food

Yam are also eaten as food. It is used as an ingredient in dishes such as Stir-fried Chinese Yam or Sautéed Yam with Soy Sauce.