Over-the-counter and natural remedies for onychomycosis: do they really work?

Onychomycosis is a fungal infection of the nail unit that may lead to dystrophy and disfigurement over time. It accounts for up to 50% of all nail conditions, with toenails affected more commonly than fingernails. Onychomycosis may affect quality of life and increase the prevalence and severity of foot ulcers in patients with diabetes. Available oral agents approved by the US Food and Drug Administration (FDA) for the treatment of onychomycosis include terbinafine and itraconazole, which have demonstrated good efficacy but are associated with the risk of systemic side effects and drug-drug interactions. Topical medications that are FDA approved for onychomycosis include ciclopirox, efinaconazole, and tavaborole. These therapies generally have incomplete efficacy compared to systemic agents as well as long treatment courses and possible local side effects such as erythema and/or blisters. Given the need for safe, effective, and cost-effective options for onychomycosis therapy, there has been a renewed interest in natural and over-the-counter (OTC) alternatives. This review will synthesize the laboratory data, known antifungal mechanisms, and clinical studies assessing the efficacy of OTC and natural products for onychomycosis treatment.