Question 1

How does Rou Gui work as a warming herb in the body?

Accepted Answer

Rou Gui (Cinnamomum cassia bark) works primarily through its active compound cinnamaldehyde, which acts as a vasodilator to improve circulation and generate warmth. In Traditional Chinese Medicine (TCM), this mechanism addresses kidney yang deficiency and cold bi-syndrome by dispersing cold and invigorating blood flow. Pharmacologically, its anti-inflammatory properties help alleviate arthritis caused by cold dampness. Evidence Level C supports these biological activities, though specific clinical trial data remains limited.

Question 2

Can I take Rou Gui while pregnant or breastfeeding?

Accepted Answer

No, Rou Gui is considered unsafe during pregnancy. As a warming herb that invigorates blood circulation, it stimulates uterine contractions and may induce miscarriage, particularly at therapeutic doses (1–5 g). Traditional use contraindicates it for pregnant women. While data on breastfeeding is limited, caution is advised due to potential transfer of active compounds like coumarin. Pregnant or nursing individuals should avoid this herb entirely unless directed by a qualified practitioner.

Question 3

What is the correct dosage for Rou Gui bark?

Accepted Answer

The standard adult dosage for Rou Gui bark is 1–5 grams as a decoction. Because heat destroys volatile oils, it should be added only during the last 5–10 minutes of cooking. For standardized extracts, 200–500 mg is common. Dosage depends on the specific formulation and condition severity. Long-term use should be monitored to avoid coumarin accumulation. Always follow a qualified herbalist's guidance rather than self-prescribing.

Question 4

Does Rou Gui interact with prescription medications?

Accepted Answer

Yes, Rou Gui has significant drug interaction potential. Due to its coumarin content, it may potentiate anticoagulant drugs like warfarin, increasing bleeding risk. Additionally, cinnamaldehyde may enhance the effects of antidiabetic medications, potentially causing hypoglycemia. Patients with liver disease should avoid it due to hepatotoxicity risks. Evidence Level C supports these interactions based on pharmacological data. Always consult a physician before combining with blood thinners or diabetes medication.

Question 5

What are the side effects of taking Cinnamomum cassia bark?

Accepted Answer

Common side effects arise from its warming nature, causing 'heat' symptoms like dry mouth, sore throat, or constipation in those with yin deficiency. The most serious concern is hepatotoxicity (liver damage) due to coumarin content, particularly with long-term use or high doses. Contraindications include yin deficiency with heat signs and existing liver disease. Evidence Level C indicates these risks are pharmacologically plausible. Discontinue use if jaundice or abdominal pain occurs.

Rou Gui

Sources & Citations

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Pregnancy & lactation

Evidence summary

PubMed sources

Government sources