Rou Gui - 肉桂 - Cortex Cinnamomi

Properties: Pungent, sweet, hot

Meridans Entered:
Primary: Kidney, Spleen, Heart and Liver
Sinews: Shaoyin
Extraordinary Vessels: Chong, Du

Traditional Actions/Indications:

Warms the Kidneys, Spleen and Heart and strengthens Yang and Ming Men Fire
Kidney Yang Deficiency and Deficiency of Ming-Men Fire with aversion to Cold, cold limbs, weak back, impotence and urinary frequency
Spleen and Kidney Yang Deficiency with abdominal pain and Cold, reduced appetite and diarrhoea
Kidney Unable to Grasp Qi
Heart Yang Deficiency, particularly with chest Bi
Disperses deep Cold, warms the channels, unblocks the channels and vessels and alleviates pain
Deep Cold causing Qi Stagnation or Blood Stasis with Cold in the Blood causing amenorrhea or dysmenorrhea, Cold-Damp Bi, Yin-type boils (chronic sores that are usually concave and ooze a clear fluid) and sores or abscesses that do not heal
It enters the Blood aspect and, in small amounts, enhances the Blood moving action of other substances
Leads the Fire back to its source
Upward Floating of Deficient Yang (False Heat, True Cold or Heat Above and Cold Below) with flushed face, wheezing, severe sweating (the sweat pours out like oil), weak and cold lower extremities and a deficient and rootless pulse
Any condition with Heat in the Upper body (dry mouth, sore throat, or teeth which is worse at night) and Cold in the Lower body (Lower back pain, cold lower extremities, diarrhoea and weakness in the proximal portion of the pulse)
Assists in the generation of Qi and Blood
Chronic Qi and Blood Deficiency (auxiliary)
Aids fasting
Mentioned in the Shen Nong Ben Cao Jing as part of the superior class of herbs which can, with protracted taking, enable one to communicate with spirits, make the body light, and prevent forgetfulness. This may suggest it was part of supplementing the diet when engaging in an "avoiding grain" (Bigu 辟穀) fasting regime to cultivate life (Yangsheng 養生).

Suggested Daily Dosage: 1-5g in decoction. It should be decocted later.

Cautions: It is contraindicated for syndrome of yin deficiency with fire effulgent, haemorrhage due to blood heat and pregnant women. It is incompatible with Chi Shi Zhi (nineteen incompatibilities).

Interactions:

Antidiabetic drugs: May have additive effect on drugs that lower blood sugar.
Anticoagulant drugs: Coumarins in cinnamon may have additive effect on drugs that slow clotting such as warfarin, heparin, aspirin and NSAIDs. This is much less of a problem for Ceylon cinnamon (C. vera).
Hepatotoxic drugs: Large doses may have liver toxicity which may increase the toxicity of hepatotoxic drugs, including acetaminophen, amiodarone, carbamazepine, isoniazid, methotrexate, methyldopa, fluconazole, itraconazole, erythromycin, phenytoin, lovastatin, pravastatin, simvastatin and others.
Should be stopped before surgery due to anticoagulant effect (University of Texas at El Paso, accessed 2021)).

Notable Constituents:

Coumarin
Aromatic class of compounds with a vanilla scent and bitter taste, which are used as precursors to anticoagulant drugs such as coumadin / warfarin which work by blocking the synthesis of Vitamin K. It is moderately toxic to the liver and kidneys, recommended at 0.1mg/kg of body weight and present in considerably higher amounts in C. cassia than C. verum (0.10 - 12.18mg per g compared to 0.005 - 0.090mg per g). This makes the Tolerable Daily Intake for a 50kg adult anywhere between 0.4 - 50g. However, it may be precisely this action that produces its effects on circulation, pain and reviving Heart Yang so it may be better to monitor dose rather than substituting unless there are specific contraindications to coumarin (e.g. already taking blood thinners, especially Warfarin).

Iwata et al., (2016) found 1g of cinnamon decoction contained 3.0mg coumarin, with a recommended safe dose of 0.1 mg/kg/day, making the effective safe dose for a 60kg individual 2g of cinnamon. 76% of patients taking herbal medicine exceeded this level, and 18% had abnormal readings on a liver function test but none showed signs of pathological changes.
Eugenol
Anti-inflammatory, neuroprotective, antipyretic, antioxidant, antifungal and analgesic phenolic molecule suggested to be responsible for its toothache controlling properties. Its exact mechanism of action is unknown, however, it has been shown to interfere with action potential conduction.
Cinnamaldehyde
Aldehyde that gives cinnamon its flavour and odour. The essential oil of cinnamon bark is about 90% cinnamaldehyde. Effective as a fungicide but with low toxicity, it is ideal for agriculture where it is applied to the root systems of over 40 crop plants. It is also used as an insecticide against mosquitoes and their larvae, a corrosion inhibitor for steel, an antimicrobial, an inducer of apoptosis in leukemia cells, an inhibitor of Tau protein formation in Alzheimer's and as a potential anti-obesity drug, activating thermogenisis causing apipose tissue to burn more energy. Despite low internal toxicity it is classified as a skin irritant, but has also been identified as promoting type I collagen biosynthesis via activation of IGF-I signaling (Takasao et al., 2012)
Cinnamic Acid
An unsaturated carboxylic acid which can be synthesized by the oxidation of cinnamaldehyde. It is used in flavouring and as a precursor to the sweetner Aspartame. It has also been investigated as a potential hair growth stimulant through oxytocin receptor activation (Kageyama et al., 2024).
Styrene
A carcinogenic compound structurally similar to cinnamaldehyde and may be formed by degradation of cinnamic acid by certain moulds growing on cinnamon (Lafeuille et al, 2009). It is present in many natural foods such as coffee and peanuts but has its highest concentrations in C. cassia (Steele et al, 1994).

Appears in 78 formulae listed on this site: (click to display)

Ai Fu Nuan Gong Wan (Mugwort and Cyperus Pill to Warm the Palace)
From: Straight Directions from Ren-Zhai (1264) by Yang Shi-Ying / Ren-Zhai

Bai Zhu Fu Zi Tang (White Atractylodes and Aconite Accessory Decoction)
From: Arcane Essentials from the Imperial Library by Wang Tao (752)

Bao Yuan Tang (Preserve the Primal Decoction)
From: Collected Treatises of Jing-Yue by Zhang Jie Bin / Zhang Jing Yue (1624)

Bu Shen Gu Chi Wan (Tonify the Kidneys to Firm the Teeth Pills)
From: Chengdu Jiuzhitang Jinding Pharmaceutical Co., Ltd.

Bu Yi Qi Guan Jiu (Supplement and Boost Lycium and Cinnamon Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Chang Ning Tang (Intestinal Serenity Decoction)
From: Fu Qing-Zhu's Women's Disorders by Fu Qing-Zhu (1826)

Chu Shi Wei Ling Tang (Eliminate Dampness by Combining Calm the Stomach and Five Ingredient Powder with Poria)
From: Golden Mirror of the Medical Tradition by Wu Qian (1742)

Chu Shi Zhu Yang Jiu (Mulberry Reinforcing Yang Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Cong Rong Qiang Zhuang Jiu (Cistanches Strengthening Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Cong Zi Jiu (Onion Seed Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Dan Shen Shi Hu Jiu (Salvia and Dendrobium Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Di Huang Yin Zi (Rehmannia Drink)
From: Comprehensive Recording of Sagely Beneficence from the Zhenghe Era (1117) by Song Imperial Court

Du Huo Ji Sheng Jiu (Pubescent Angelica and Taxillus Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Du Huo Ji Sheng Tang (Pubescent Angelica and Taxillus Decoction)
From: Important Formulas Worth a Thousand Gold Pieces by Sun Si Miao (650)

Fu Biao Zheng Hong Hua You (Axe Brand Original Red Flower Oil)
From: Product information sheet by Leung Kai Fook Medical Co. Ltd

Gu Zhen Tang (Stabilise the True Decoction)
From: Indispensable Tools for Pattern Treatment by Wang Ken-Tang (1602)

Gui Fu Li Zhong Tang (Cinnamon Twig and Prepared Aconite Root Decoction to Regulate the Middle)
From: Traditional Chinese Internal Medicine (c. 1970) by Shanghai College of TCM

Gui Ling Gan Lu Yin (Cinnamon and Poria Sweet Dew Drink)
From: Formulas from the Discussion Illuminating the Yellow Emperor's Basic Questions (1172) by Liu Wan-Su

Gui Ling Gan Lu Yin (Cinnamon and Poria Sweet Dew Drink)
From: Confucians' Duties to Their Parents by Zhang Cong-Zheng / Zi-He (1228)

Guo Qi Yin (Delayed Menstruation Drink)
From: Indispensable Tools for Pattern Treatment by Wang Ken-Tang (1602)

Huang Qi Dang Gui Jiu (Astragalus and Tangkuei Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Huang Qi Du Zhong Jiu (Astragalus and Eucommia Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Hui Yang Jiu Ji Tang (Restore and Revive the Yang Decoction)
From: Six Texts on Cold Damage (1445) by Tao Hua

Hui Yang Jiu Ji Tang (Revive the Yang in Emergencies Decoction)
From: Revised Popular Guide to the Discussion of Cold Damage by Yu Gen-Chu, Revised by He Bing-Yuan (Qing dynasty)

Huo Xue Jiu (Quicken the Blood Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Ji Sheng Shen Qi Wan (Life Saver Kidney Qi Pill)
From: Formulas to Aid the Living by Yan Yong-He (1253)

Jiao Tai Wan (Grand Communication Pill)
From: Comprehensive Medicine According to Master Han (1522)

Jin Yang Guang Gao (Golden Sunshine Paste)
From: Product label by Sheng Chun Tang Pharmaceuticals

Ju He Wan (Tangerine Seed Pill)
From: Formulas to Aid the Living by Yan Yong-He (1253)

Juan Bi Tang (Remove Painful Obstruction Decoction)
From: Awakening of the Mind in Medical Studies by Cheng Guo-Peng (1732)

Kang Zhuang Jiu (Robust Health Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Long Chi Qing Hun San (Dragon's Tooth Powder to Clear the Ethereal Soul)
From: Comprehensive Medicine According to Master Zhang (1695) by Zhang Lu-Yu / Shi-Wan

Nei Bu Dang Gui Jian Zhong Tang (Internally Tonifying Tangkuei Decoction to Construct the Middle)
From: Important Formulas Worth a Thousand Gold Pieces by Sun Si Miao (650)

Nei Bu Huang Qi Tang (Astragalus Decoction to Tonify the Interior)
From: Formulas Bequeathed by the Unorthodox Genius Liu Jian-Zi (499) by Liu Jian-Zi

Niu Xi Dan Shen Jiu (Achyranthes and Salvia Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Niu Xi Fu Zi Jiu (Achyranthes and Aconite Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Niu Xi Rou Gui Jiu (Achyranthes and Cinnamon Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Niu Xi Shi Hu Jiu (Achyranthes and Dendrobium Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Nuan Gan Jian (Warm the Liver Decoction)
From: Collected Treatises of Jing-Yue by Zhang Jie Bin / Zhang Jing Yue (1624)

Qian Jin Nei Tuo San (Powder to Support the Interior Worth a Thousand Gold Pieces)
From: Restoration of Health from the Myriad Diseases by Gong Ting-Xian (1587)

Qian Lie Shu Wan (Prostate Comfort Pills)
From: Aura Herbs (2020)

Que Lao Jiu (Step Back from Old Age Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Ren Shen Fu Ling Jiu (Ginseng and Poria Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Ren Shen Yang Rong Tang (Ginseng Decoction to Nourish Luxuriance)
From: Discussion of Illnesses, Patterns and Formulas Related to the Unification of the Three Aetiologies (1174)

San Bi Tang (Three Painful Obstruction Decoction)
From: Fine Formulas for Women (1237)

Shao Fu Zhu Yu Tang (Drive Out Stasis from the Lower Abdomen Decoction)
From: Correction of Errors Among Physicians by Wang Qing-Ren (1830)

Shao Yao Tang (Peony Decoction)
From: Discussion of Cold Damage by Zhang Zhong-Jing (c. 220)

Shen Xiao Tai Yi Gao (Wonderously Effective "Tai Yi" [great medicine] Ointment)
From: Categorised Essentials of Repairing the Body by Xue Ji (1548)

Shi Bu Wan (Ten Tonic Pill)
From: Formulas to Aid the Living by Yan Yong-He (1253)

Shi Liu Wei Liu Qi Yin (Sixteen Ingredient Drink for Qi Flow)
From: Introduction to Medicine (1575) by Li Chan / Jian-Zhai

Shi Quan Da Bu Tang (All Inclusive Great Tonifying Decotion)
From: Transmitted Trustworthy and Suitable Formulas (1180)

Shu Di Dang Shen Tang (Prepared Rehmannia and Codonopsis Decoction)
From: Journal of Ethnopharmacology 324, 117786 by Xiao-min Liu, Hui Shi & Wei Li (2024)

Su Zi Jiang Qi Tang (Perilla Fruit Decoction for Directing Qi Downward)
From: Important Formulas Worth a Thousand Gold Pieces by Sun Si Miao (650)

Suan Zao Ren Jiu (Zizyphus Spinosa Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Tan Yin Wan (Phlegm and Thin Mucus Pill)
From: Shaanxi New Medicine (1972)

Tong Guan Wan (Open the Gate Pill)
From: Secrets from the Orchid Chamber by Li Gao / Li Dong Yuan (1276)

Tuo Hua Jian (Out-Thrusting and Transforming Decoction)
From: Collected Treatises of Jing-Yue by Zhang Jie Bin / Zhang Jing Yue (1624)

Wen Jing Tang (Flow Warming Decoction)
From: Fine Formulas for Women (1237)

Wen Pi Tang (Warm the Spleen Decoction)
From: Formulas of Universal Benefit from my Practice (1132)

Wu Ji San (Five Accumulations Powder)
From: Secret Formulas to Manage Trauma and Reconnect Fractures Received from an Immortal (c. 846)

Wu Ling Tong Guan Tang (Five Ingredients with Poria Decoction to Open the Gate)
From: Case Histories of Cheng Men-Xue (2002) by Cheng Men-Xue

Wu Zhu Yu Tang (Evodia Decoction )
From: Comprehensive Recording of Sagely Beneficence from the Zhenghe Era (1117) by Song Imperial Court

Xiao Qi Qi Tang (Minor Seven Emotions Decoction)
From: Formulary of the Pharmacy Service for Benefiting the People of the Taiping Era by Tai Yi Ju (Imperial Medical Bureau) (1107)

Xiao Xu Ming Tang (Minor Extend Life Decoction)
From: Formulas with Short Articles (Jin Dynasty, 4th Century)

Yan Hu Suo San (Corydalis Powder)
From: Formulas to Aid the Living by Yan Yong-He (1253)

Yan Hu Suo Tang (Corydalis Decoction)
From: Formulas to Aid the Living by Yan Yong-He (1253)

Yang He Tang (Temperate Yang Decoction)
From: Complete Collection of Pattern and Treatments in External Medicine (1740)

Yang Rong Jiu (Nourish the Constructive Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Yang Xin Tang (Nourish the Heart Decoction)
From: Indispensable Tools for Pattern Treatment by Wang Ken-Tang (1602)

Yao Tong Pian (Lumbar Pain Pills)
From: Aura Herbs (2020)

Yao Yun (Hot Medical Compress)
From: Divine Pivot Classic by Unknown but given by the character Bo Gao (Pre-Qin to late Han dynasty)

Yin Chen Zhu Yu Tang (Virgate Wormwood, Atractylodes and Aconite Decoction)
From: Awakening of the Mind in Medical Studies by Cheng Guo-Peng (1732)

You Gui Wan (Restore the Right [Kidney] Pill)
From: Collected Treatises of Jing-Yue by Zhang Jie Bin / Zhang Jing Yue (1624)

You Gui Yin (Restore the Right [Kidney] Drink)
From: Collected Treatises of Jing-Yue by Zhang Jie Bin / Zhang Jing Yue (1624)

Zan Yu Dan (Special Pill to Aid Fertility)
From: Collected Treatises of Jing-Yue by Zhang Jie Bin / Zhang Jing Yue (1624)

Zhen Ren Yang Zang Tang (True Man's Decoction to Nourish the Organs)
From: Formulary of the Pharmacy Service for Benefiting the People of the Taiping Era by Tai Yi Ju (Imperial Medical Bureau) (1107)

Zhou Gong Bai Sui Jiu (Master Zhou's Hundred Years Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Zong Zi Yao Jiu (Boosting Progeny Medicinal Wine)
From: Chinese Medicinal Wines and Elixirs (2008) by Various

Research Links & References: (click to display)

Individual Herbs Notebook

肉 桂  Rou Gui

Translation: Cinnamon Flesh

Pharmaceutical: Cortex Cinnamomi
Taxonomy: Cinnamomum cassia

Other names: Cinnamon Bark / Tvak त्वक् / Dar Sini دارچین / Qirfa قرفة

Category: Herbs that Warm the Interior and Expel Cold

Research Links:

Reference Notes: