Tacrolimus, also known by its brand name Prograf among others, is an immunosuppressive drug used in transplantation to reduce the risk of organ rejection. It is also used in the treatment of certain skin conditions like eczema and in the management of autoimmune diseases. Tacrolimus is typically administered orally or topically in the form of ointments or creams. Here is some content about Tacrolimus and its active pharmaceutical ingredient (API):