Use with caution. Review interactions and contraindications below.
TCM Properties
- Taste
- acrid, sweet
- Temperature
- warm
- Channels
- Heart, Lung, Bladder
Traditional Use
Primary Actions
- Releases the exterior and harmonizes the nutritive and defensive Qi - Gui Zhi is the classic warm, acrid twig for Wind-Cold patterns with spontaneous sweating, aversion to wind, stiff neck, and disharmony between Ying and Wei, especially as expressed in the Gui Zhi Tang pattern.
- Warms and unblocks the channels and collaterals - it is used for cold-damp joint pain, numbness, cold-constrained menstruation, and channel obstruction where warming circulation is needed without the deeper, stronger interior heat of Rou Gui.
- Warms Yang and assists Qi transformation - Gui Zhi is classically applied when the Bladder's transforming function is impaired by cold or Yang weakness, leading to edema, poor fluid movement, or chest and epigastric fullness from constrained Yang.
- Unblocks Heart Yang and moves chest Qi - its light but penetrating warmth makes it useful in chest Bi presentations, palpitations, or cold-type chest discomfort when Yang obstruction and phlegm coexist.
Secondary Actions
- Gui Zhi is frequently paired with Bai Shao to regulate the relationship between defensive and nutritive Qi rather than simply pushing sweat or heat outward.
- Although it comes from the same tree as Rou Gui, Gui Zhi acts more superficially and at the channel level, while Rou Gui penetrates more deeply to restore Ming Men fire and severe interior cold.
Classic Formulas
- Gui Zhi Tang (桂枝汤) - foundational Shang Han Lun formula for Wind-Cold with spontaneous sweating and Ying-Wei disharmony, with Gui Zhi as the chief exterior-releasing and harmonizing herb.
- Dang Gui Si Ni Tang (当归四逆汤) - classic formula for cold in the channels with cold hands and feet, where Gui Zhi warms and unblocks the vessels so Blood can circulate to the extremities.
- Wen Jing Tang (温经汤) - gynecologic classic for cold in the Chong and Ren with irregular menstruation, infertility, or abdominal pain, using Gui Zhi to warm the channels and dispel congealed cold.
- Zhi Shi Xie Bai Gui Zhi Tang (枳实薤白桂枝汤) - Jin Gui Yao Lue formula for chest Bi, where Gui Zhi helps open Yang and move constrained cold-phlegm in the chest.
Classical References
- Me and Qi describes Gui Zhi as warm, acrid, and sweet, entering the Heart, Lung, and Bladder channels and especially suited to releasing Wind-Cold while warming channels and assisting fluid transformation.
- Classical formula tradition consistently distinguishes Gui Zhi from Rou Gui by medicinal part and clinical depth: twig for surface and channel harmonizing, bark for deeper Yang restoration.
- Quality-control discussions in modern materia medica note that true Gui Zhi should be slender young twigs and not old dark branches or leaf-stalk-heavy adulterated material.
Modern Research
Active Compounds
- Cinnamaldehyde (phenylpropanoid aldehyde) - the best-known bioactive cinnamon constituent and a major anti-inflammatory research marker in twig as well as bark preparations
- 2-methoxycinnamaldehyde and related cinnamaldehyde derivatives - compounds tied to nitric-oxide and cytokine modulation in experimental inflammation studies
- Coumarin (benzopyrone) - a safety-relevant constituent when cinnamon products are used in large or prolonged doses
- Linalool, camphor, and other essential-oil terpenoids - part of the volatile aromatic fraction isolated from Cinnamomum cassia twigs
- Phenolic constituents such as caffeic-acid-related compounds - contribute to antioxidant and cell-signaling research on twig extracts
Studied Effects
- Essential oil isolated from Cinnamomum cassia twigs alleviated experimental pain and inflammation in mice, giving twig-specific support to Gui Zhi's classical warming-and-unblocking reputation (PMID 27780753).
- A rat study found anti-inflammatory and anti-arthritic effects from Cinnamomum cassia twigs in both acute and chronic arthritis models, aligning with traditional use for cold-damp painful obstruction (PMID 34015366).
- A broad review of Cinnamomum cassia summarizes the plant's phytochemistry, pharmacology, and toxicology, including twig-related essential-oil constituents and anti-inflammatory activity (PMID 31557828).
PubMed References
Safety & Interactions
Contraindications
- Warm or febrile disorders without cold involvement
- Yin deficiency with Heat signs
- Blood-heat bleeding or excessive sweating from fluid depletion
Cautions
- Gui Zhi is lighter than Rou Gui but can still aggravate heat signs, thirst, restlessness, or bleeding if used in the wrong pattern
- Some cinnamon products contain coumarin levels high enough to raise liver-safety concerns with excessive intake
- Gastrointestinal upset and allergic reactions have been reported with cinnamon products
Drug Interactions
-
CYP450 substrate drugs
— Preclinical studies suggest cinnamon inhibits CYP2A6, CYP2C9, CYP2D, and CYP3A4 and may increase the risk of side effects from drugs metabolized by these enzymes (Moderate)
Source: Memorial Sloan Kettering Integrative Medicine - Cinnamon
-
Statins
— Concurrent use has been associated with hepatitis in a case report (Moderate)
Source: Memorial Sloan Kettering Integrative Medicine - Cinnamon
-
Pioglitazone
— Animal studies suggest cinnamon can increase pioglitazone bioavailability (Moderate)
Source: Memorial Sloan Kettering Integrative Medicine - Cinnamon