Herbs that can “warm the interior” belong to a category of Chinese medicinal herbs used to treat various internal cold syndromes and their associated symptoms. Most of the herbs in this category are widely used culinary spices and traditionally consumed in winter for their warming properties.
- Fu Zi and Wu Tou (Aconite Root)
- Gan Jiang (Dried Ginger)
- Rou Gui (Chinese Cinnamon Bark)
- Wu Zhu Yu (Evodia Fruit)
- Xi Xin (Chinese Wild Ginger)
- Hua Jiao (Sichuan Pepper)
- Gao Liang Jiang (Lesser Galangal Rhizome)
- Ding Xiang (Clove)
- Hu Jiao (Black Pepper)
- Bi Ba (Long Pepper)
- Xiao Hui Xiang (Fennel Seed)
Internal Cold Syndrome can develop in two ways: due to external invasion of pathogenic cold (acute), or deficiency of yang of the internal organs (chronic). The general actions of these herbs are to expel cold, warm the meridians and internal organs, promote qi and blood circulation, alleviate pain and cramp caused by cold.
Interior warming herbs are contraindicated for those with excess heat and yin deficiency syndromes. If you frequently eat spices such as ginger, cinnamon, pepper, clove or fennel seeds please pay attention to the contraindicated symptoms below.
Fu Zi and Wu Tou (Aconite Root)
Aconite (Aconitum carmichaelii) is a herbaceous, flowering plant species belonging to the buttercup family. It is native to the mountainous parts of north east Asia, particularly in China and Japan. Many species of aconite are cultivated in gardens, having either blue or yellow flowers. The plant is highly toxic and its roots contain the alkaloid aconitine which can cause numbness and tingling when touched to the lips and skin.
Aconite has long history of use in the traditional medicines of Asia, including traditional Chinese medicine and Ayurveda. Aconite was also described in Greek and Roman medicine. Several species of aconite have been used as arrow poisons for hunting and warfare. Also known as wolfsbane and monkshood, aconite has appeared in many popular literary works including Shakespeare, Dracula and Harry Potter.
Fu Zi and Wu Tou both come from the roots of the same plant. Fu Zi is the thin and long lateral root of the plant while Wu Tou is the main root. The root is harvested in autumn as the plant dies down and is then dried and specially processed with ginger to reduce its toxicity before use.
Fu Zi (Radix Aconiti Lateralis Praeparata) is an important herb in the Chinese materia medica because of its potency and versatility. If administered alone, it has a moderate cardiotonic effect, short duration and numerous side effects. Therefore it is generally combined with other herbs such as Gan Cao or Gan Jiang to synergistically increase the therapeutic effect of the formula and minimise its toxicity. It can also be combined with Da Huang to treat constipation, Huang Lian for epigastric distension, Yin Chen Hao for yin-jaundice, Long Dan Cao for liver damp-heat affecting the spleen and Sheng Di Huang to nourish blood.
Wu Tou (Radix Aconiti Carmichaeli) is better able to expel wind-cold, warm the meridians and relieve pain, while Fu Zi is regarded as more potent for its ability to warm Kidney-Yang (combined with Rou Gui) and rescue Yang from collapse (combined with Ren Shen). Both herbs are indicated for the treatment of arthritic cold bi-syndrome.
Gan Jiang (Dried Ginger)
Gan Jiang (Rhizoma Zingiberis) is the dried rhizome of the plant Zingiber officinale. Garden ginger is widely used in many parts of the world because of its valuable medicinal and culinary uses. Ginger cultivation began in south-east Asia and is commercially grown in the tropical regions of east Africa, China, Jamaica and India, the latter being the world’s largest producer.
Around the world, ginger is mixed with mango tree sap as a panacea in Congo, to relieve nausea, headache, the common cold in India and Nepal, to relieve fatigue, prevent and cure rheumatism in Indonesia, as a throat lozenge in the Philippines, stomach aches in Peru and clinically proven for pregnancy-related nausea and vomiting in the United States.
Its active constituents have been shown to exert antioxidative, antitumorigenic, anti-inflammatory and immunomodulatory effects in vitro and it is an effective antimicrobial and antiviral agent.
In Chinese medicine, Gan Jiang targets the Spleen, Stomach, Heart and Lung meridians and is used in formulas to relieve symptoms of abdominal pain, asthmatic cough, indigestion, diarrhoea and constipation due to interior cold syndromes. Chinese medicine also uses the fresh ginger rhizome which has slightly different actions for the relief of acute nausea, vomiting and externally contracted colds.
According to the Chinese materia medica, Gan Jiang should be used with caution during pregnancy.
Rou Gui (Chinese Cinnamon Bark)
Rou Gui (Cinnamomi Chinensis Cortex) is the bark of the cassia tree (Cinnamomum Aromaticum) also known as Chinese cinnamon. It is a small evergreen tree native to southern China, Bangladesh, India and Vietnam. Medicinal Rou Gui is produced mainly in the areas of Guangdong, Guangxi and Yunnan.
Cassia is a close relative to, and often confused with Ceylon cinnamon (C. verum) which is the well-known culinary spice native to India and Sri Lanka. Cassia is also similar to Saigon cinnamon (C. loureiroi), camphor laurel (C. camphora) and Indonesian cinnamon (C. burmannii). Whole branches and small trees are harvested for cassia bark, which gives it a much thicker and rougher texture than the small shoots used to produce true cinnamon spice. Cassia sticks are extremely hard and usually made of one thick layer, whereas cinnamon sticks have many thin layers and can be easily ground.
Rou Gui is primarily indicated for Kidney-Yang deficiency syndrome displaying symptoms of sore and cold lower back and knees, abdominal pain, diarrhoea, impotence, infertility and menstrual disorders due to cold.
Wu Zhu Yu (Evodia Fruit)
Wu Zhu Yu (Fructus Evodiae Rutaecarpae) is the fruit of the evodia tree (Tetradium ruticarpum) which grows to 9m tall in temperate to tropical south east Asia. Also known as the beebee tree, tetradium is popular amongst beekeepers because it flowers in late summer when few other trees do and attracts large numbers of bees. The flowers produce clusters of red berries which ripen and expose tiny black seeds throughout autumn. The fruit is gathered in August or November and dried in the sun. The mildly toxic fruit is soaked in a decoction of Gan Cao (licorice root) before use.
Wu Zhu Yu is as pungent and hot as Fu Zi and can warm the liver meridian, disperse and descend liver qi. Indications for Wu Zhu Yu include vertex headache, cold cramping pain in the stomach or sides of the lower abdomen.
Xi Xin (Chinese Wild Ginger)
Xi Xin (Herba Asari Cum Radice) belongs to the Aristolochiaceae family of low-growing herbs found across the temperate zones of the northern hemisphere. In China, it thrives in the moist, humus-rich forest soils of Huayin at elevations above 1,200 metres.
Xi Xin has distinctive heart-shaped leaves which grow from the rhizome just beneath the soil surface. Two leaves emerge each year from the growing tip. The herb has fine roots and a very pungent taste. It is harvested in autumn and dried for later use. Xi Xin is traditionally indicated for the relief of wind-cold pain and can warm the lung to eliminate cold phlegm and fluids.
Safety warning: Xi Xin has similar names or appearance with other plants in the Aristolochia family. There is a risk that Xi Xin may be confused, substituted or adulterated with other botanicals that contain Aristolochic acid, which is a carcinogenic and nephrotoxic substance (refer to precautions below).
Hua Jiao (Sichuan Pepper)
The Chinese Prickly-ash (Zanthoxylum simulans) is a flowering plant native to eastern China and Taiwan. It is one of several species of Zanthoxylum from which Sichuan pepper is produced. Hua Jiao is the outer reddish brown husk of the small 3-4mm berry that splits open to release shiny black seeds. Only the husks are used.
Despite its name, Sichuan pepper is not related to black pepper, but is widely used as a spice in the cuisine of Sichuan, China from which it takes its name. It is also important in Tibetan, Bhutanese and Nepalese cuisine since few spices can grow in these regions. Hua Jiao has a unique aroma and flavour that is not hot or pungent like black pepper or chili. It has an alkaline pH and a numbing effect on the lips when eaten in large doses.
Since Hua Jiao is slightly toxic and moves quickly in the middle jiao, it is only used for acute excessive damp-cold syndrome for a short duration. It can relieve severe abdominal pain and cramp in the abdomen, frequent watery stools and urination due to cold.
Gao Liang Jiang (Lesser Galangal Rhizome)
Lesser galangal (Alpinia officinarum) is a plant belonging to the ginger family native to China. Although it resembles ginger, there is little similarity in taste. Lesser galangal has a reddish brown skin and flesh with a stronger, sweeter taste than greater galangal. Greater galangal (Alpinia galanga) which has a lighter yellow coloured flesh is more commonly used in Asian cuisines such as Thai tom yum soup and curries.
Lesser galangal was widely used in ancient and medieval Europe, and is still used as a spice and medicine in Lithuania and Estonia. In Chinese medicine, Gao Liang Jiang has a strong action in warming the Spleen and Stomach to treat epigastric symptoms such as cramping pain, vomiting and diarrhoea due to cold.
Ding Xiang (Clove)
Cloves are the strongly aromatic dried flower buds of Eugenia caryophyllata, a tree native to the Spice Islands of Indonesia. It is now cultivated in many tropical regions including Madagascar, Tanzania, South America, Indonesia, Malaysia and Sri Lanka.
The young flower buds change from a pale colour to green, then bright red which is when they are ready to be collected.
Cloves are used as a spice in cuisines all over the world, in the production of perfumes and incense, in Chinese medicine, Ayurveda and western herbalism. The essential oil is used as a painkiller in dental emergencies. Cloves can increase hydrochloric acid in the stomach and improve peristalsis.
Ding Xiang targets the stomach, spleen and kidney meridians to warm Kidney-Yang, direct rebellious qi downwards and warm the middle jiao to relieve epigastric and abdominal pain, vomiting and diarrhoea due to cold.
Hu Jiao (Black Pepper)
Black pepper (Piper nigrum) is a flowering vine native to India which has been prized for its fruit, the peppercorn, since at least 2000 BCE. It is extensively cultivated in tropical regions, with Vietnam being the world’s largest producer and exporter of pepper – the world’s most traded spice.
Black pepper is produced from the green unripe drupes of the pepper plant. Fully mature peppercorns turn dark red in colour. The drupes are blanched in hot water and dried during which the pepper around the seed shrinks and darkens giving black peppercorn its wrinkly appearance.
Hu Jiao is indicated for warming the middle jiao to relieve epigastric and abdominal pain, vomiting and diarrhoea due to cold.
Bi Ba (Long Pepper)
Long pepper (Piper longum) belongs to the same family as black pepper and has a similar but hotter taste. The pepper fruit consists of many minuscule fruits embedded in the surface of a flower spike. First discussed as a medicament by Hippocrates, it was an important spice to the ancient Greeks and Romans until it was displaced by black pepper in the fourteenth century. Long pepper is widely used Ayurvedic medicine (pippali) for its longevity enhancing effects. Bi Ba (Piperis longi fructus) also warms the middle jiao with similar effects as Hu Jiao.
Xiao Hui Xiang (Fennel Seed)
Fennel (Foeniculum vulgare) is a bulbous plant native to the shores of the Mediterranean and western Asia. It is a member of the celery family and well-known for its aromatic aniseed flavour which features in Mediterranean, Middle Eastern and Asian cooking. The entire plant is edible but only fennel seeds and extracts are used medicinally.
Xiao Hui Xiang (Foeniculi fructus) is not a true seed but the fruit of the fennel plant with the appearance of a dry seed 4–10 mm long. It is cultivated in all parts of China where the fruit is collected in autumn as it ripens and dried in the sun.
Xiao Hui Xiang can warm the middle jiao and enter the kidney and liver meridians to relieve abdominal and epigastric pain, hernia due to cold and improve the appetite.
Precautions and contraindications
Interior warming herbs are hot in nature and contraindicated for patients with existing Heat or Yin Deficiency syndromes. It is advisable to avoid interior warming herbs if you experience symptoms of excess heat, thirst, night sweating, red tongue with no coating, sore lower back and knees.
Fu Zi, Gan Jiang, Rou Gui, Wu Zhu Yu, Hua Jiao, Xiao Hui Xiang are contraindicated during pregnancy and should be used under careful supervision of a qualified Chinese medicine practitioner.
Rou Gui may be toxic to the kidneys and cause haematuria if taken in large doses. Wu Zhu Yu should not be used in large doses or for long periods of time.
Xi Xin is a botanical product at risk of containing toxic Aristolochic acids. All species of Aristolochia are prohibited for supply, sale or use in therapeutic goods in Australia. Refer to the TGA Practitioner Alert about botanical products containing Aristolochia species and Aristolochic Acid [PDF].
- Chen JK, Chen TT. Chinese medical herbology and pharmacology, Art of Medicine Press, City of Industry CA.
- Yang, Y. 2010, Chinese herbal medicines: comparisons and characteristics, 2nd edn, Churchill Livingstone, Edinburgh.
- Unraveling the story of xi xin [http://asarumunfurled.wordpress.com/]