Calamus root (Acorus calamus)

Tier 4 — risky / avoid · Carcinogen · Beta-asarone

Contains beta-asarone, classified as a probable human carcinogen by international authorities. FDA banned calamus as a food additive in 1968 after animal studies showed it causes intestinal tumours. Still found in some traditional Ayurvedic and Chinese medicine products. The European variety contains the highest beta-asarone levels. There is no safe dose for internal consumption. No clinical trial has demonstrated any therapeutic benefit.

Dose: AVOID — beta-asarone is a probable carcinogen; FDA banned as food additive in 1968