Eden Apothecary · Herb Profile
Cinnamomum cassia
Pronounced Cassia: KASH-uh (also KAS-ee-uh). Cinnamomum cassia: sin-uh-MOH-mum KASH-ee-uh. Rou Gui: roh gway.
Hot and drying: an acrid, sweet, aromatic bark that rekindles the deep vital fire, warms and awakens a cold, torpid digestion and a cold lower body, and, unlike its gentler cousin true cinnamon, carries a coumarin load that caps the safe dose.
Food amounts appear safe; avoid medicinal and concentrated doses. Culinary quantities of cassia are generally regarded as acceptable in pregnancy, but therapeutic doses are traditionally avoided: Grieve and later materia medica class cinnamon bark as an emmenagogue that can stimulate the uterus, and animal studies indicate that cinnamaldehyde exposure during pregnancy may harm the fetus. NCCIH states cassia cinnamon in amounts commonly found in foods is likely safe in pregnancy while larger amounts lack safety data, and the AHPA Botanical Safety Handbook does not certify high-dose use. Given the emmenagogue reputation, the coumarin burden, and the absence of safety data at medicinal doses, avoid therapeutic or supplemental cassia in pregnancy; seasoning food is not a concern. (NCCIH; AHPA Botanical Safety Handbook, 2nd ed.; Grieve, A Modern Herbal; Brinker, Herbal Contraindications and Drug Interactions.)
Food amounts appear compatible; avoid concentrated doses. Cassia as a food spice is generally considered compatible with breastfeeding. Grieve notes that cinnamon bark can reduce the secretion of milk (a mild lactifuge or anti-galactagogue reputation), so large or sustained medicinal doses may be undesirable for a mother wishing to maintain supply, and the coumarin content argues against concentrated, prolonged use. No specific infant toxicity is documented at culinary intake. Use food amounts; avoid therapeutic doses and the neat essential oil while nursing. (Grieve, A Modern Herbal; NCCIH; AHPA Botanical Safety Handbook, 2nd ed.)
Culinary amounts are fine; avoid medicinal doses, the coumarin burden, and the neat oil. Cassia as a food spice is acceptable for children. Medicinal or supplemental doses are not advised, because a child reaches the coumarin tolerable daily intake at a much lower amount than an adult (small body weight times the 0.1 mg per kg ceiling), and the essential oil (cinnamaldehyde) is a strong mucous-membrane irritant that has caused chemical burns and must never be given neat or used near the face of infants and young children. Any therapeutic pediatric use should be practitioner-directed at low, short-course, food-level dosing. (EFSA coumarin tolerable daily intake; NCCIH; AHPA Botanical Safety Handbook, 2nd ed.)
Cassia bark is rich in coumarin (roughly 1,000 to 6,000 mg per kg, about 0.1 to 0.6 percent, far more than Ceylon cinnamon), and coumarin is hepatotoxic in susceptible people at sustained high intake. The European Food Safety Authority sets a tolerable daily intake of 0.1 mg coumarin per kg body weight (about 6 mg for a 60 kg adult), a ceiling that a single teaspoon of cassia powder can exceed, so medicinal, concentrated, or long-term use should be practitioner-guided rather than casual self-dosing, and is inappropriate for anyone with liver disease. It is hot and acrid: it can aggravate heartburn, gastritis, and any heat or yin-deficient pattern. The essential oil (largely cinnamaldehyde) is a potent mucous-membrane and skin irritant and sensitizer that must be diluted and never taken neat. Cassia also lowers blood glucose and carries mild coumarin anticoagulant activity, both of which matter alongside medication (see Drug Interactions).
Pregnancy at therapeutic doses (emmenagogue and uterine stimulant; see Pregnancy Safety). Liver disease or concurrent hepatotoxic-drug therapy (coumarin load). Yin deficiency with heat, interior heat and fire, and heat-type bleeding (TCM). Known allergy or contact sensitivity to cinnamon or cinnamaldehyde, or to balsam of Peru or tolu (cross-reactivity). Caution with anticoagulants and antidiabetic medication. The concentrated essential oil is not for internal use except under professional guidance.
Cinnamomum cassia is not at risk. It is a widely cultivated plantation tree of southern China (Guangxi, Guangdong), Vietnam (the source of 'Saigon cinnamon'), and Indonesia, grown at commercial scale for bark, buds, and oil, so supply is agricultural rather than wild-harvested and there is no conservation concern. It is not listed by United Plant Savers (a North American native-plant registry). The practical stewardship issues are quality and authenticity: cassia is routinely sold simply as 'cinnamon', and adulteration or confusion between cassia and Ceylon bark is common, so buy species-verified bark from reputable suppliers. Because the coumarin hazard tracks the cassia type specifically, clear labeling that distinguishes C. cassia from C. verum is itself a form of consumer protection.
Yes. Cassia is one of the sacred spices of the holy anointing oil, 'and of cassia five hundred shekels' (Exodus 30:24, Hebrew qiddah), and it perfumes the King's robes in Psalm 45:8 (Hebrew qetsiah/ketziot: 'all thy garments smell of myrrh, and aloes, and cassia'); it also appears as an article of Tyrian commerce in Ezekiel 27:19. Traditional and most botanical commentators identify the biblical cassia with the aromatic inner bark of Cinnamomum cassia (or a closely allied cassia-lignea) imported to the ancient Near East from eastern Asia and India, though the precise species behind the two Hebrew terms is debated. The spice was well known to the classical Mediterranean world (Greek kasia), noted by Herodotus, Theophrastus, Dioscorides, and Pliny.
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