The rhizome of the sweet sedge has long been rumoured as a psychoactive substance with possible hallucinogenic properties. However, it seems that it is not Calamus but a similar, possibly related plant that may have such properties- for Calamus this claim has not been substantiated. This confusion stems from a possible mistranslation of a herb's name found in Dioscorides' writings.
Calamus does in fact have stimulating and warming properties that can have a useful therapeutic effect. Its main application has been in the treatment of stomach complaints and as a detoxifying tonic that rids the body of waste materials. It is strongly diuretic and can be used in cases of oedema. Calamus is also reputed to be a powerful nervous system tonic and as a useful herb for the mind and memory. In Tibetan medicine incense containing Calamus root is used therapeutically as a nerve tonic. Externally, a decoction of Calamus can be added to the bathwater as a stimulating, warming additive, e.g. in inflammatory or scrofulous skin conditions, chilblains and the like and is also said to strengthen feeble children.
Although probably not as an entheogen, Calamus has long played a role in magical herbalism. It has been used for protection, especially from snakes and snake bites, as well as from evil spirits. In medieval Europe the leaves were used as a strewing herb whilst the aromatic roots were burnt as incense. It also has a long tradition as an aphrodisiac in both Europe and Asia, and in India Calamus root is considered nourishment for the Kundalini snake.