# Cassia Cinnamon (Cinnamomum cassia)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/cassia-cinnamon
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-31
**Evidence Score:** 2 / 10
**Category:** Spice
**Also Known As:** Chinese cinnamon, Cassia bark, Bastard cinnamon, Rou gui, Cinnamomum aromaticum, Baker's cinnamon, Saigon cinnamon, Korintje cinnamon, Indonesian cinnamon, Padang cassia

## Overview

Cassia cinnamon (Cinnamomum cassia) contains cinnamaldehyde and type-A procyanidins as its primary bioactive compounds, which improve [insulin sensitivity](/ingredients/condition/weight-management) by activating insulin receptor signaling and inhibiting protein tyrosine phosphatase 1B (PTP1B). These compounds also slow gastric emptying and inhibit intestinal alpha-glucosidase enzymes, reducing postprandial blood glucose spikes.

## Health Benefits

• Reduces peak blood glucose response by 10-16 mg/dL in obese women during glucose tolerance testing (moderate evidence from crossover trial)
• Lowers fasting blood glucose by 10.3-29% in type 2 diabetics (strong evidence from systematic review of 3 RCTs)
• Decreases postprandial blood glucose by 7-13 mg/dL in diabetics (moderate evidence from 12-week trial)
• May attenuate [insulin resistance](/ingredients/condition/weight-management) in sleep loss models (preliminary evidence from review)
• Potentially reduces plasma lipids in type 2 diabetics (limited evidence from open trial)

## Mechanism of Action

Cinnamaldehyde and type-A procyanidins in Cassia cinnamon activate insulin receptor autophosphorylation and inhibit PTP1B, enhancing downstream GLUT4 translocation to cell membranes and increasing peripheral glucose uptake. These compounds also inhibit intestinal alpha-glucosidase and alpha-amylase enzymes, slowing carbohydrate [digestion](/ingredients/condition/gut-health) and blunting postprandial glucose excursions. Additionally, cinnamaldehyde activates TRPA1 receptors and may modulate GLP-1 secretion, contributing to improved glycemic control through an incretin-mediated pathway.

## Clinical Summary

A systematic review of 3 RCTs in type 2 diabetic patients demonstrated that Cassia cinnamon supplementation (1–6 g/day) lowers fasting [blood glucose](/ingredients/condition/weight-management) by 10.3–29% compared to placebo. A crossover trial in obese women found that 3 g of Cassia cinnamon reduced peak blood glucose by 10–16 mg/dL during oral glucose tolerance testing. Postprandial glucose reductions of approximately 7–30% have been observed in additional controlled trials, though effect sizes vary with dose, duration, and baseline glycemic status. Evidence is strongest for short-term fasting glucose reduction in type 2 diabetics; long-term [cardiovascular](/ingredients/condition/heart-health) and HbA1c outcomes require larger confirmatory trials.

## Nutritional Profile

Per 100g dried Cassia Cinnamon powder: Calories ~247 kcal, Carbohydrates ~80.6g (of which dietary fiber ~53.1g, representing dominant macronutrient fraction), Protein ~3.99g, Fat ~1.24g (primarily polyunsaturated and saturated fatty acids in roughly equal fractions). Key minerals: Calcium ~1002mg (high but bioavailability limited by oxalate content), Iron ~8.32mg, Manganese ~17.5mg (exceptionally high, exceeding daily requirements in typical serving sizes), Magnesium ~60mg, Phosphorus ~64mg, Potassium ~431mg, Zinc ~1.83mg. Vitamins present in modest amounts: Vitamin K ~31.2mcg per 100g, Vitamin A ~15 IU, small amounts of B vitamins (B6 ~0.158mg, folate ~6mcg). Primary bioactive compounds: Cinnamaldehyde (60-75% of essential oil fraction, the dominant phenylpropanoid responsible for most pharmacological effects), Coumarin at notably high concentrations of 1,000-12,000mg/kg dry weight (significantly higher than Ceylon cinnamon at <100mg/kg — a critical safety distinction), Cinnamyl acetate (~3% of essential oil), Eugenol (~10% of essential oil), Procyanidin-type polyphenols (primarily type-A procyanidins) estimated at ~8,000mg/kg dry weight, trans-cinnamic acid, and smaller amounts of linalool and camphor. Bioavailability notes: Cinnamaldehyde is rapidly absorbed via gastrointestinal tract but undergoes extensive first-pass [metabolism](/ingredients/condition/weight-management) to cinnamic acid and hippuric acid; polyphenol absorption is moderate (~5-10%) and enhanced by fat co-ingestion; coumarin is well-absorbed (near complete oral bioavailability) and accumulates with repeated use, posing hepatotoxicity risk at intakes exceeding 0.1mg/kg body weight/day — a threshold reachable with as little as 1-2 teaspoons daily of Cassia variety specifically. Typical culinary serving (1 teaspoon ≈ 2.6g) provides approximately 26-31mg coumarin, ~1.6-1.95g cinnamaldehyde, and ~208mg polyphenols.

## Dosage & Preparation

Clinically studied doses range from 1g/day (capsules) for 9-12 weeks for glucose control, 5g single dose before glucose testing, up to 12g/day (6g twice daily) in impaired glucose tolerance studies. Studies used whole bark powder in capsules, not standardized extracts. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Cassia cinnamon contains coumarin at concentrations of 1–12 mg/g of powder, which poses hepatotoxicity risk at chronic high doses; the European Food Safety Authority set a tolerable daily intake of 0.1 mg/kg body weight for coumarin, limiting safe Cassia intake to roughly 0.5–1 g/day for a 70 kg adult with daily use. Cassia cinnamon can potentiate the blood-glucose-lowering effects of insulin, metformin, sulfonylureas, and other antidiabetic medications, increasing hypoglycemia risk and requiring dose monitoring. It may also interact with hepatotoxic drugs or anticoagulants such as warfarin due to coumarin content affecting CYP2A6 [metabolism](/ingredients/condition/weight-management). Cassia cinnamon is not recommended in pregnancy at supplemental doses due to uterine-stimulating properties of cinnamaldehyde and insufficient safety data.

## Scientific Research

Clinical evidence includes a crossover trial (n=10) showing 5g Cassia reduced peak glucose but not [insulin sensitivity](/ingredients/condition/weight-management) (PMID: 26716656), and a systematic review finding 2 of 3 RCTs demonstrated 10.3-29% fasting glucose reduction in type 2 diabetics (PMID: 18066129). However, a 12-week RCT using 12g daily found no insulin sensitivity changes via gold-standard clamp testing (PMID: 25249415).

## Historical & Cultural Context

Cassia cinnamon has historical use in traditional Chinese medicine for glucose regulation and metabolic disorders. Modern clinical trials for type 2 diabetes and prediabetes build upon this traditional foundation, though specific duration and system details are not elaborated in current research.

## Synergistic Combinations

Chromium picolinate, alpha-lipoic acid, bitter melon extract, gymnema sylvestre, fenugreek seed

## Frequently Asked Questions

### How much cassia cinnamon should I take to lower blood sugar?

Clinical trials showing blood glucose reductions in type 2 diabetics used doses ranging from 1 to 6 grams per day, with 1–3 g/day being the most commonly studied effective dose. However, because Cassia cinnamon contains coumarin, daily supplemental use should generally not exceed 0.5–1 g/day to stay within the EFSA's tolerable daily intake of 0.1 mg coumarin per kg body weight and avoid liver toxicity risk.

### What is the difference between cassia cinnamon and Ceylon cinnamon for blood sugar?

Most clinical evidence for blood glucose lowering comes from Cassia cinnamon (Cinnamomum cassia), which has higher concentrations of cinnamaldehyde and type-A procyanidins than Ceylon cinnamon (Cinnamomum verum). Ceylon cinnamon contains negligible coumarin (less than 0.017 mg/g vs. up to 12 mg/g in Cassia), making it safer for long-term daily use, but it has less direct clinical trial evidence supporting glycemic efficacy at equivalent doses.

### Can cassia cinnamon damage your liver?

Yes, chronic high-dose consumption of Cassia cinnamon poses a hepatotoxicity risk due to its coumarin content, which can reach 1–12 mg per gram of powder. Coumarin is metabolized by CYP2A6 into a reactive epoxide that causes hepatocellular damage in susceptible individuals; case reports of cinnamon-induced liver injury exist at intakes exceeding the EFSA tolerable daily intake. People with pre-existing liver conditions or those on hepatotoxic medications should avoid supplemental Cassia cinnamon entirely.

### Does cassia cinnamon interact with metformin or diabetes medications?

Cassia cinnamon has additive blood-glucose-lowering effects when combined with metformin, insulin, or sulfonylureas, increasing the risk of hypoglycemia. Patients on antidiabetic medications who add cinnamon supplementation should monitor blood glucose more frequently and consult their physician about potential dose adjustments. The interaction is pharmacodynamic rather than pharmacokinetic for most antidiabetics, though coumarin in Cassia may also mildly inhibit CYP2A6, potentially affecting drug metabolism.

### How long does it take for cassia cinnamon to lower blood sugar?

Postprandial blood glucose reductions can occur acutely within 30–60 minutes of ingestion due to alpha-glucosidase inhibition slowing carbohydrate absorption. Sustained reductions in fasting blood glucose in type 2 diabetics have been observed after 40 days to 4 months of consistent supplementation at 1–6 g/day in the RCTs included in systematic reviews. The timeline depends heavily on baseline glycemic status, dose, and dietary consistency.

### What is the most effective form of cassia cinnamon for blood sugar control—powder, extract, or whole stick?

Clinical trials showing blood sugar benefits have primarily used cassia cinnamon powder at doses of 1-6 grams daily, making powder the most studied and evidence-supported form. Water-soluble extracts may offer faster absorption, but standardized extracts lack the robust clinical data that whole powder possesses. Whole cinnamon sticks provide minimal bioavailable compounds compared to ground powder, making them less effective for therapeutic blood sugar management.

### Who should avoid cassia cinnamon supplementation due to coumarin content?

Individuals taking anticoagulant medications (warfarin, dabigatran) should consult a healthcare provider before supplementing, as cassia cinnamon contains high levels of coumarin that may potentiate bleeding risk. People with liver disease or compromised hepatic function should also exercise caution or avoid cassia cinnamon due to potential coumarin accumulation. Pregnant women and those with coumarin sensitivity should limit intake to culinary amounts unless medically supervised.

### Does consuming cassia cinnamon with food improve its blood sugar-lowering effectiveness?

Taking cassia cinnamon with meals—particularly meals high in carbohydrates—appears to maximize its blood glucose-reducing effect, as clinical trials documenting the 10-16 mg/dL reductions typically administered it with glucose challenges or meals. Taking cinnamon on an empty stomach has not been shown to be superior and may cause gastrointestinal discomfort. Consistency of timing relative to meals is more important than whether it is taken fasted or fed.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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