Short answer: Cassia cinnamon contains coumarin, a consideration at higher intakes at higher intakes for anyone with a liver condition — a specific, named caution for this particular cinnamon variety.
Why "Cassia" specifically, not cinnamon generally, is named
Different cinnamon varieties carry different coumarin levels — naming Cassia specifically reflects a more precise, checkable caution than a generic cinnamon warning.
Who should be most attentive to this specific caution
Anyone with a liver condition, and anyone taking the formula at higher intakes over long periods — two specific circumstances worth discussing with a doctor.
💡 Worth knowing: cinnamon is described as the gentlest of the actives here — a comparatively modest caution relative to berberine's more significant interaction profile.