How much cinnamon is too much?

For cassia cinnamon, "too much" is mostly a coumarin question, not a cinnamon-toxicity question. A 2012 analysis of retail cassia found enough coumarin that a daily bark dose in the low grams can cross Europe's tolerable intake for that compound. Ceylon cinnamon's coumarin content is low enough that the same math doesn't apply the same way.

The cassia ceiling is about coumarin

The European Food Safety Authority sets a tolerable daily intake for coumarin of 0.1 mg per kilogram of body weight — about 7 mg a day for a 70 kg adult. A 2012 analysis of 60 retail cinnamon samples found cassia cinnamon averaging 2,650 to 7,017 mg of coumarin per kilogram of bark. Working through that range: a 70 kg adult would reach the 7 mg tolerable intake somewhere between roughly 1 and 2.6 grams of cassia bark a day, depending on the specific product — well within a multi-capsule bark-powder serving. Cinnamon dosage walks through the full table and how it scales for a different body weight.

Ceylon doesn't have the same ceiling

The same 2012 analysis found a Ceylon sample, sourced directly from a Sri Lankan plantation, with no detectable coumarin. At ordinary supplement doses, that means Ceylon cinnamon doesn't run into the same practical upper limit — the coumarin math simply doesn't produce a ceiling the way it does for cassia. That's a difference in one specific, measurable risk, not a blanket claim that Ceylon has no upper limit of any kind; see who should not take cinnamon for the other things worth checking regardless of species.

Signs of too much, regardless of species

Separately from coumarin, concentrated bark powder can cause stomach upset in some people, particularly at the higher end of trial doses (several grams a day). Mouth or lip irritation is a documented reaction to cinnamon-flavored products like gum or candy, not to swallowed capsules. Cinnamon side effects covers what's actually documented for both, including how thin the data is on exact rates.

No established toxic dose

We haven't found a human trial or case series that establishes a toxic or fatal dose of cinnamon. The coumarin ceiling above is a liver-safety margin drawn from a regulatory tolerable intake, not a documented poisoning threshold — it's the most concrete number available, but it isn't the same thing as an overdose limit.

Questions people ask

What happens if you take too much cinnamon supplement?

For a cassia product taken well above the coumarin math above, the concern is liver stress at high, sustained intake (see cinnamon side effects). At a simpler level, more bark powder in one sitting can mean more stomach upset. There's no documented acute-overdose scenario in the human literature.

Is there a maximum daily amount of cinnamon supplement?

No single number applies to every product — it depends on the species and the form (bark powder vs. extract). For cassia, the practical ceiling comes from coumarin math, worked out above and in cinnamon dosage. For Ceylon, that specific ceiling isn't in play at typical doses.

Can you overdose on cinnamon supplements?

No case of a cinnamon overdose in the sense of acute poisoning is documented in the literature we found. The real, documented risk at high sustained intake is coumarin's link to liver injury for cassia specifically — a slow-accumulation concern, not a single-dose one.

Related reading: cinnamon dosage, cinnamon side effects, and Ceylon vs. cassia cinnamon.