Griseofulvinis an antifungal drug that is administered orally. It is used both in animals and in humans, to treat fungal infections of the skin and nails. It is produced by culture of some strains of the mold Penicillium griseofulvum. The drug binds to tubulin, interfering with microtubule function, thus inhibiting mitosis. It binds to keratin in keratin precursor cells and makes them resistant to fungal infections. It is only when hair or skin is replaced by the keratin-griseofulvin complex that the drug reaches its site of action. Griseofulvin will then enter the dermatophyte through energy dependent transport processes and bind to fungal microtubules. This alters the processing for mitosis and also underlying information for deposition of fungal cell walls. Griseofulvin is used orally only for dermatophytosis. It is ineffective topically. Griseofulvin is reserved for cases with nail, hair or large body surface involvement.