Gui Zhi (Cinnamomum cassia): Benefits, Dosage, Safety & Evidence

Frequently asked questions

How does Gui Zhi work in the body?

Gui Zhi works primarily through its active compound cinnamaldehyde, which acts as a vasodilator to improve blood flow and generate warmth. In Traditional Chinese Medicine (TCM), it functions to harmonize the Ying and Wei Qi, helping to release exterior cold from the body. This mechanism supports its use for poor circulation, muscle pain, and warming the body surface. Evidence Level: C.

Does Gui Zhi interact with blood thinners?

Yes, Gui Zhi has potential interactions with anticoagulant and antiplatelet medications. Because the herb promotes blood circulation and contains coumarin derivatives, taking it alongside drugs like warfarin or aspirin may increase the risk of bleeding. It is contraindicated for individuals with bleeding disorders and should be avoided by those on blood-thinning therapy unless supervised by a physician. Evidence Level: C.

What is the standard dosage for Gui Zhi?

The standard adult dosage for Gui Zhi is typically 3 to 9 grams daily, usually prepared as a decoction. The specific amount depends on the formulation and the condition being treated, such as exterior cold or palpitations. Because it is a warming herb, dosage should be carefully monitored to avoid excessive internal heat or sweating. Evidence Level: Traditional.

Is Gui Zhi safe to take during pregnancy?

No, Gui Zhi is considered unsafe during pregnancy and is strictly contraindicated. The herb stimulates blood circulation and warms the uterus, which can promote uterine contractions and increase the risk of miscarriage. Pregnant individuals should avoid this herb and consult a qualified practitioner for safer alternatives to treat colds or circulation issues. Evidence Level: C.

What are the side effects of taking Gui Zhi?

Common side effects of Gui Zhi include excessive sweating and a sensation of warmth or heat due to its acrid nature. It is contraindicated for individuals with Yin deficiency or heat signs, as it can exacerbate symptoms like dry mouth or night sweats. Overuse may lead to fluid depletion or increased heart rate in sensitive individuals. Evidence Level: C.

PubMed-compiled information sheet

This sheet was compiled from PubMed (NIH) abstracts using AI assistance. Every factual claim is cited to a real PubMed article (see the source list). It has not yet been human-reviewed — confirm with a healthcare provider before use.

Compiled from 30 PubMed articles · model: gemma4:31b

Summary

Gui Zhi (Cinnamomum cassia) is a tropical aromatic evergreen tree used globally as a spice and in traditional medicine for its diverse pharmacological properties [PMID:31557828, PMID:26142534].

Background

Cinnamomum cassia Presl, belonging to the Lauraceae family, is a medicinal-food homologous plant commonly used in traditional Chinese medicine [PMID:31557828, PMID:41957048].

Traditional uses

It is used in traditional Chinese, Japanese (Kampo), Ayurvedic, and Unani medicine to manage conditions such as dyspepsia, peptic ulcer disease, ischemic brain injury, and diseases resulting from kidney yang deficiency, including diabetic nephropathy [PMID:26142534, PMID:25725434].

Active compounds

The herb contains terpenoids, phenylpropanoids, and glycosides [PMID:31557828]. Cinnamaldehyde is the most abundant compound in the buds [PMID:29145172], and other identified components include syringaresinol (a lignan) [PMID:40780474] and a purified polysaccharide designated CCP1A [PMID:42282441].

Mechanism of action

Cinnamaldehyde operates by inhibiting the NF-κB pathway, modulating pro-inflammatory mediators, and disrupting bacterial cells [PMID:38903995]. Other mechanisms include the SIRT1/FOXO1-autophagy axis for liver protection [PMID:41957048], AMPK activation for cognitive protection [PMID:40780474], and the modulation of vascular endothelial tight junctions and neuroinflammation [PMID:40507090].

Clinical evidence

Evidence CType 2 Diabetes Mellitus

Cinnamon enhanced glucose transport and enzyme inhibition; human studies showed reductions in fasting blood glucose (12.9 to 52.2 mg/dL) and HbA1c (0.27 to 0.83%) [PMID:40641727, PMID:30144878]

Evidence BAcute and Chronic Gastritis

A phase II trial of CKD-495 (extracted from C. cassia) showed a significantly higher endoscopic erosion improvement rate (73%) compared to other groups (41-52%) [PMID:40255536]

Evidence CGout

Cinnamomum cassia was identified as having high xanthine oxidase inhibitory activity (>85%) [PMID:29628890]

Safety & adverse effects

Cinnamaldehyde was evaluated for safety using the CCK8 method and high-dose administration in mice [PMID:38663778].

Drug interactions

Literature indicates that Cinnamomum cassia has anti-coagulant activity and should be prescribed with care to patients on anticoagulant therapy [PMID:28866770].

Evidence summary

Evidence ranges from high-level human clinical trials for gastritis and diabetes to preclinical animal models for neuroprotection and liver disease, with significant support for its anti-inflammatory and hypoglycemic effects.

PubMed sources

1.PMID: 39736250 (2025) — Bioinformatics identification based on causal association inference using multi-omics reveals the underlying mechanism of Gui-Zhi-Shao-Yao-Zhi-Mu decoction in modulating rheumatoid arthritis. · Phytomedicine : international journal of phytotherapy and phytopharmacology
2.PMID: 29145172 (2018) — Volatiles from Cinnamomum cassia buds. · Zeitschrift fur Naturforschung. C, Journal of biosciences
3.PMID: 29628890 (2018) — Anti-gout Potential of Malaysian Medicinal Plants. · Frontiers in pharmacology
4.PMID: 35004802 (2021) — A Review on the Mechanism and Application of Keishibukuryogan. · Frontiers in nutrition
5.PMID: 28866770 (2017) — Anti-coagulant activity of plants: mini review. · Journal of thrombosis and thrombolysis

Gui Zhi

Sources & Citations

Calculate a safe dose of Gui Zhi

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Frequently asked questions

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Drug interactions

Evidence summary

PubMed sources

Government sources

Gui Zhi

Sources & Citations

Calculate a safe dose of Gui Zhi

Related Herbs

Lavandula latifolia

Heal All Spica

Jahe Merah

Frequently asked questions

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Drug interactions

Evidence summary

PubMed sources

Government sources