Individual Herbs Notebook

Gui Zhi

Translation: Cinnamon Twig

Pharmaceutical: Ramulus Cinnamomi
Taxonomy: Cinnamomum cassia

Other names: Cinnamon Twig

Category: Herbs that Release the Exterior



Properties: Pungent, sweet, warm

Meridans Entered:
Primary: Lung, Heart, Kidney, Liver
Sinews: Taiyang
Divergent Zones: Taiyang
Extraordinary Vessels: Du, Yin Wei, Yang Wei


Traditional Actions/Indications:
  1. Releases the Exterior, assists Yang, adjusts the Ying and Wei and releases the muscle layer
    Taiyang Wind Strike (Taiyang Zhongfeng, 太阳中风) - a weak person who catches cold easily with spontaneous sweating, aversion to drafts, fever and chills, nasal congestion, stiff and aching head and muscles
  2. Warms the channels and collaterals to relieve pain
    Wind-Cold-Damp Bi
  3. Unblocks Yang and transforms Qi and thin mucus
    Edema due to Cold-Phlegm or Yang Qi Deficiency with urinary dysfunction, dizziness and palpitations
  4. Assists Heart Yang and warms and facilitates the flow of Yang Qi in the chest
    Palpitations due to Yang Obstruction in the chest due to Stagnation or Deficiency
    Listless chest Yang with upward movement of Phlegm and thin mucus and disorderly descent of Lung Qi with shortness of breath, chest and back pain and palpitations
    Heart and Spleen Yang Deficiency
  5. Warms and facilitates the flow of Qi through the channels and collaterals and Blood through the vessels
    Wind-Cold-Damp Bi
    Blood Stasis due to Cold, causing amenorrhea or dysmenorrhea with or without abdominal masses
  6. Warms the Middle and directs Turbid Yin downward
    Middle Jiao Yang Deficiency
    Heart and Spleen Yang Deficiency (patient usually craves sweets)

Suggested Daily Dosage: 3-10g in decoction for exterior conditions, or up to 15g for Bi Syndromes.


Cautions: This herb induces heat, damages the yin and moves blood. It is prohibited for those with warm pathogens, yin deficiency with effulgent fire, or reckless movement of the blood due to heat in the blood. Use with caution in pregnant women.


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.
  • 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. Coumarins are 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.
  • 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.
  • 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 77 formulae listed on this site: (click to display)
Research Links & References: (click to display)