Terbinafine is widely used as an antifungal agent, particularly in the treatment of fungal infections affecting the skin, hair, and nails. It is highly effective against dermatophytes, the fungi responsible for conditions such as athlete’s foot, jock itch, and ringworm. Due to its fungicidal action, it not only inhibits fungal growth but also kills the pathogens, leading to a lower recurrence rate.

One of its major applications is in the oral and topical treatment of onychomycosis, a stubborn fungal infection of the nails. Oral terbinafine is considered a first-line treatment because of its high cure rates and ability to penetrate the nail bed effectively. Topical formulations, such as creams and sprays, are used for superficial skin infections, offering targeted therapy with minimal systemic absorption.

Its selective mechanism of action—blocking ergosterol synthesis, a key component of fungal cell membranes—makes it less toxic to human cells, contributing to a favorable safety profile. Terbinafine is also used in veterinary medicine to treat fungal infections in animals.