The nail plate disorders can result from somatic disease in a patient, mere lack of certain trace elements and vitamins in the body, or exposure to various mechanical and chemical factors. The disease of the nail matrix is inevitably accompanied by nail changes, which clinically manifest as atrophy, hypertrophy, keratinization disorder, and destruction. The paper presents the overview of the main clinical forms of onychodystrophy. We present the results of our own clinical studies of two drug products (vitamin complex and complex of microelements and macroelements) in treatment of onychodystrophy. The study involved 42 patients with onychodystrophies of different genesis (psoriatic, traumatic, and chemical). Patients were divided into two groups; 19 patients received Evisent (brewer’s yeast with sulfur), and 23 patients received Merz Spezial Dragees. The efficacy was monitored by visual inspection and onychoscopy, which was conducted in patients before treatment and then 3 and 5 months after initiation of therapy. Complete recovery of the nail plate was observed in 36% of patients; significant clinical improvement in the structure of the nail was observed in 55% of patients; slight clinical improvement of the nail plate was observed in 9% of patients. The studies have shown that Merz Spezial Dragees and Evisent (brewer’s yeast with sulfur) have an identical effect and equal efficacy in treatment of nail plate disorders and may be recommended for treatment of onychodystrophies of any origin.