Thalix 100mg & 200mg( Thalidomide ) Capsules affects the immune system. It helps promote immune responses to prevent inflammation in the body. Thalix 100mg & 200mg ( Thalidomide ) Capsules is used to treat and prevent the debilitating and disfiguring skin sores caused by erythema nodosum leprosum (ENL), an inflammatory complication of leprosy. It is also used together with another medicine called dexamethasone to treat multiple myeloma (bone marrow cancer)