Safety & Dosage Guide
Cinnamon is one of the most popular health supplements in the world — but safe daily intake depends entirely on which type you're using. This guide covers the evidence, the EFSA guidelines, and how to calculate your own safe limit.
Written & reviewed by
Sarah Chen
Health & Wellness Writer · Melbourne, Australia
Sarah is a health and wellness writer specialising in evidence-based nutrition content. All articles are researched against peer-reviewed clinical literature — following strict editorial guidelines. This content is for educational purposes only — not medical advice.
Most people don't realise there are several distinct species sold as "cinnamon." The two most relevant for daily supplementation are Ceylon cinnamon (Cinnamomum verum) and Cassia cinnamon (Cinnamomum aromaticum), and their safety profiles differ dramatically.
The key compound is coumarin — a naturally occurring chemical that is toxic to the liver and kidneys at elevated doses. Cassia cinnamon contains approximately 2,100–4,400mg of coumarin per kg. Ceylon cinnamon contains roughly 170mg/kg — about 18 times less.
| Type | Coumarin content | Safe daily amount (70kg adult) | Risk level |
|---|---|---|---|
| Ceylon (C. verum) | ~170mg/kg | Up to ~4g/day | Low |
| Cassia (C. aromaticum) | ~2,100–4,400mg/kg | ~700mg/day max | Moderate |
| Saigon (C. loureirii) | ~6,950mg/kg | ~200mg/day max | High |
Source: EFSA TDI 0.1mg coumarin/kg/day. Coumarin concentrations from Woehrlin et al. (2010), Journal of Agricultural and Food Chemistry.
The European Food Safety Authority (EFSA) established a Tolerable Daily Intake (TDI) of 0.1mg of coumarin per kilogram of body weight per day. This is the maximum amount considered unlikely to cause adverse effects over a lifetime of exposure.
This standard was informed by animal studies showing hepatotoxicity (liver damage) at sustained high coumarin doses, and supported by human case reports of liver enzyme elevations in individuals consuming large amounts of Cassia cinnamon or coumarin-containing foods regularly.
Your personalised Cassia limit (EFSA TDI):
50kg
~5mg coumarin/day
~240mg Cassia max
70kg
~7mg coumarin/day
~330mg Cassia max
90kg
~9mg coumarin/day
~430mg Cassia max
Note: Cassia coumarin content varies by source. These are conservative estimates based on ~2,100mg coumarin/kg Cassia.
Most clinical research on cinnamon's health effects uses between 1g and 6g of cinnamon extract per day, typically for 8–16 weeks. The most commonly studied doses are 1g, 2g, and 3g per day. Below is a summary of doses used in landmark trials:
1g/day
RCTBlood sugar (T2DM)
Significant reductions in fasting glucose and HbA1c vs placebo (Crawford 2009, Khan et al. 2003)
1–3g/day
Meta-analysisLDL cholesterol
Reductions of 9–26% in multiple trials; greatest effect in those with highest baseline cholesterol
1.5g/day
RCTPCOS
Improved insulin sensitivity and menstrual regularity in pilot RCT (Wang et al. 2007)
3g/day
RCTInflammation (CRP)
Significant reduction in CRP and IL-6 biomarkers in overweight adults
6g/day (acute)
RCTGlycaemic response
Slowed gastric emptying by 37%, reducing post-meal blood glucose spike
Note: Unless specified, studies used Cassia cinnamon. Ceylon cinnamon at equivalent doses is expected to show similar efficacy due to shared cinnamaldehyde content, but with a superior safety profile.
For Ceylon cinnamon, the coumarin content is low enough that the limiting factor is general tolerance, not coumarin toxicity. Most evidence-based guidelines suggest:
For Cassia cinnamon, apply the EFSA formula: multiply your body weight in kg by 0.1mg (your coumarin TDI), then divide by the coumarin concentration of your product (typically ~2.1mg/g for standard Cassia). This gives you the maximum grams of Cassia cinnamon per day.
Formula for Cassia maximum:
Max g/day = (Body weight kg × 0.1) ÷ 2.1
For a 70kg person: (70 × 0.1) ÷ 2.1 ≈ 3.3g Cassia max. But this is already well above amounts providing meaningful health benefits, so just switch to Ceylon.
People with liver conditions
Coumarin is hepatotoxic at high doses. Use Ceylon only and discuss with your hepatologist.
Those on blood thinners (warfarin, aspirin)
Cinnamaldehyde has mild anticoagulant properties. Monitor INR more closely if adding cinnamon supplements.
People on diabetes medications (metformin, insulin)
Cinnamon may have additive blood-glucose-lowering effects. Monitor glucose levels and adjust medication with your doctor.
Pregnant women
High-dose cinnamon supplements may stimulate uterine contractions. Culinary amounts (< 1g/day) are generally considered safe.
Chronic kidney disease (CKD)
Cinnamon contains oxalates which can accumulate in impaired kidneys. Use low doses of Ceylon only.
Children under 12
No established safe dosing exists for children. Culinary use is fine; avoid supplements.
A heaped teaspoon of cinnamon powder is approximately 2.6g — so culinary use at 1–2 teaspoons per day is broadly consistent with therapeutic doses used in research. However, supplement capsules offer two key advantages:
Whether you use powder or capsules, the same dosage principles apply. What matters most is the type of cinnamon (Ceylon for daily use), the dose (1–3g/day for most goals), and consistency (most studies run 8+ weeks before meaningful results appear).
For general wellness
1g/day Ceylon
~½ tsp powder or 2 × 500mg capsules
For blood sugar support
1–2g/day Ceylon
Taken with meals for best effect
For anti-inflammatory
2–3g/day Ceylon
Divide across 2–3 meals
For PCOS / hormonal
1.5g/day Ceylon
Consistent daily use over 3+ months
Maximum safe (long-term)
≤6g/day Ceylon
Evidence above 6g/day is limited
Cassia cinnamon
Occasional only
Not recommended for daily supplementation
Ceylon vs Cassia: Complete Safety Guide →
The definitive comparison of cinnamon types
Cinnamon and Type 2 Diabetes →
25+ RCTs reviewed — what the evidence shows
Interactive Dosage Calculator →
Calculate your personalised dose by weight & goal
Is Cinnamon Safe for Kidneys? →
What CKD patients and older adults need to know
Free: Cinnamon Safety & Dosage Guide PDF
Dosage tables, coumarin safety limits, drug interactions & Australian product tips — all in one reference PDF.
Medical Disclaimer: This article is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before starting any supplement regimen, especially if you have existing health conditions or take medications. Read our full disclaimer →