Herbs (Global Traditional) · Traditional Chinese Medicine
Rou Gui (Cinnamomum cassia) (Cinnamomum cassia)
Strong Evidencebotanical
Hermetica Superfood Encyclopedia
Rou Gui (Cinnamomum cassia) contains hydroxychalcone compounds that may improve insulin sensitivity by activating blood proteins responsible for cellular glucose uptake. This traditional Chinese medicine herb also supports digestive health by stimulating gastrointestinal secretions and relieving smooth muscle spasms.
Rou Gui is the dried bark of Cinnamomum cassia Presl, a tropical tree native to southern China, particularly Guangxi, Guangdong, and Yunnan provinces. The bark is harvested and dried to produce the spice, with the usable portion called Cinnamomi cortex. The plant material contains over 160 identified phytochemicals, primarily composed of volatile oils (1-2% by weight) dominated by cinnamaldehyde and cinnamic acid.
The available research consists primarily of experimental and animal studies rather than human clinical trials. While C. cassia is referenced as effective in clinical and experimental research for treating weakened intelligence related to ischemic cerebrovascular mechanisms, no specific RCTs with PMIDs or detailed methodologies are provided in the current literature review.
Specific clinically studied dosage ranges are not available in the current research. The bark contains 1-2% volatile oil by weight, but no standardized dosing protocols or extract concentrations have been established through clinical trials. Consult a healthcare provider before starting any new supplement.
Rou Gui (Cinnamomum cassia) is used in small medicinal doses (1-9g dried bark typically), so macronutrient contribution is minimal in clinical use. Per 100g dried bark: Carbohydrates ~80g (predominantly dietary fiber ~53g, with small amounts of simple sugars); Protein ~4g; Fat ~1.2g. Key micronutrients per 100g: Manganese ~17.5mg (875% DV - notably high), Calcium ~1002mg, Iron ~8.3mg, Magnesium ~60mg, Phosphorus ~64mg, Potassium ~431mg, Zinc ~1.8mg, Vitamin K ~31.2mcg. Primary bioactive compounds: (1) Cinnamaldehyde (trans-cinnamaldehyde) - dominant volatile compound comprising 55-90% of essential oil, responsible for antimicrobial and anti-inflammatory effects; (2) Coumarin - present at significantly higher concentrations than Ceylon cinnamon, ranging 2,100-4,400mg/kg dried bark (a key distinguishing feature of cassia vs. C. verum, with hepatotoxicity concerns at high doses); (3) Hydroxychalcones, particularly A-type procyanidins and cinnamate esters - implicated in insulin sensitization via GLUT4 translocation; (4) Cinnamic acid and cinnamate derivatives ~1-3% dry weight; (5) Tannins and condensed proanthocyanidins ~1-2%; (6) Eugenol in trace amounts (<1% of essential oil, lower than Ceylon cinnamon); (7) Polyphenolic polymers (Type-A procyanidins) estimated 1.8-3.0% dry weight. Bioavailability notes: Cinnamaldehyde is rapidly absorbed but undergoes extensive first-pass metabolism to cinnamic acid; coumarin bioavailability is high (oral bioavailability ~72%), raising safety concerns with prolonged use - European Food Safety Authority established a TDI of 0.1mg/kg body weight; fat-soluble compounds including cinnamaldehyde show enhanced absorption with lipid-containing meals; aqueous extracts yield primarily water-soluble polyphenols while essential oil preparations concentrate volatile compounds.
Hydroxychalcone compounds in Rou Gui activate glucose transport proteins in cell membranes, enhancing insulin sensitivity and glucose uptake. The herb stimulates parasympathetic nervous system activity, increasing digestive enzyme secretion and gastric motility. Essential oils containing cinnamaldehyde provide antispasmodic effects on gastrointestinal smooth muscle through calcium channel modulation.
Most evidence for Rou Gui comes from mechanistic studies and traditional use rather than large-scale clinical trials. Small human studies suggest modest improvements in glucose metabolism markers, but sample sizes have been limited to fewer than 100 participants. Traditional medicine literature documents digestive benefits, though controlled clinical evidence remains sparse. More robust randomized controlled trials are needed to establish definitive therapeutic effects and optimal dosing protocols.
Rou Gui is generally well-tolerated in traditional culinary amounts but may cause gastrointestinal irritation at higher doses. The herb can potentiate blood glucose-lowering medications, requiring careful monitoring in diabetic patients. Coumarin content may interact with anticoagulant medications and could cause liver toxicity with prolonged high-dose use. Pregnant and breastfeeding women should avoid therapeutic doses due to potential uterine stimulant effects.
