The causes of male infertility remain unclear in 30–75% cases and are considered idiopathic. The study of influence of free oxygen radicals on the male reproductive function is of outmost interest. Given the important role of hyaluronidase in the penetration of sperm into the egg, we decided to evaluate the drug Longidaza, which has long-acting enzymatic (proteolytic) activity. A total of 48 men with idiopathic infertility were included in the study. All patients were divided into two groups (24 men each). In Group 1 there was a recommendation to attempt to conceive for 1 year without additional treatment. In Group 2, patients were prescribed Longidaza according to the proposed scheme. During the follow-up, there was a significant improvement in the antioxidant defense system of the ejaculate in Group 2, which was accompanied by an increase in the fertilizing ability of the ejaculate and an increase in number of conceptions by 29.1%

Keywords: ejaculate, proteolytic enzymes, acrosome reaction, Longidaza, male infertility