adjuvant

(noun) an additive that enhances the effectiveness of medical treatment.

(adj) furnishing added support. Synonyms: accessory, adjunct, ancillary, appurtenant, auxiliary. Examples: "An ancillary pump." "An adjuvant discipline to forms of mysticism." "The mind and emotions are auxiliary to each other."

(adj) enhancing the action of a medical treatment. Example: "The adjuvant action of certain bacteria."