What is Coumarin: A Guide from a Vietnamese Cinnamon Farmer

If you love cinnamon, you’ve probably heard the word “coumarin” and wondered whether you should worry. As a farmer from Xuan Ai Commune in Lao Cai, where our family has grown cinnamon for generations, let me explain what coumarin actually is — clearly, honestly, and without the scare stories.

What Is Coumarin?

Coumarin is a natural compound found in many plants, including cinnamon. It’s responsible for that sweet, warm, pleasant aroma we all love. It isn’t an additive or a contaminant — it occurs naturally in the bark. The key thing to understand is that the amount depends on the type of cinnamon.

Why Cassia Has More Than Ceylon

Not all cinnamon carries the same coumarin level. Cassia cinnamon — the variety we nurture here in Xuan Ai, and the type most common worldwide — naturally contains more coumarin than Ceylon (“true”) cinnamon. That higher content is part of what gives cassia its bold, distinctive aroma and flavour. Ceylon is milder in both taste and coumarin.

Is Coumarin Safe?

In the sweet, everyday amounts most people use — a sprinkle on oatmeal, a stick in your coffee or stew, a dash in baking — coumarin is not a concern. The consideration only arises with large amounts consumed regularly over a long time, because in high doses coumarin can stress the liver in sensitive individuals. For normal culinary use, cinnamon remains one of the world’s most cherished and safe spices.

How Much Is Too Much?

Regulatory bodies use a tolerable daily intake for coumarin of about 0.1 mg per kilogram of body weight. For an average adult that works out to a modest few grams of cassia per day before it becomes a concern — well above a normal sprinkle, but reachable if you take large cinnamon supplements daily. If you want the full breakdown by body weight and teaspoons, read our dedicated guide on how much cinnamon per day is safe.

How Harvest and Quality Affect Coumarin

Here in Lao Cai, cooler autumn temperatures of 15–20°C give us the ideal harvest window. Careful cultivation, the right harvest timing and proper sun-drying all influence the final quality of the bark. Good farming doesn’t eliminate coumarin — it’s natural — but honest, quality harvesting means you know exactly what you’re getting, with consistent aroma and no hidden fillers.

Should You Choose Ceylon or Cassia?

If you consume very large daily amounts and want the lowest coumarin, Ceylon is the gentler pick. If you want bold flavour and use cinnamon in normal culinary quantities, cassia — like our Vietnamese cinnamon — gives you the richest aroma with no real cause for worry. The smart approach is simple: enjoy cinnamon for its flavour and benefits, and just be mindful with very high daily doses.

Ready to experience authentic, carefully harvested Vietnamese cinnamon? Explore our Vietnamese Cassia Sticks (Whole Quills) — hand-harvested and shipped direct from our family farm in Lao Cai. Learn more about our story.