Male infertility is a complex multifactorial disease and a real health problem; 50% of infertile men have identifiable causes detectable by fundamental sperm analysis. Numerous research studies have shown the possibility of treating abnormal semen samples with some drugs before artificial insemination, yet evidence of the drug's effectiveness remains minimal. In our previous work, we tested the effectiveness of some essential oils, such as eucalyptus (Eucalyptus globulusLabill.), oregano (Origanum vulgareL.), and sage (Salvia officinalisL.) on sperm parameters. The essential oil of oregano showed the best ameliorative effect. In present, we examined the effect of the essential oil ofO. vulgareon the physiological parameters and the specific activity of certain antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), lipid peroxidation rate (MDA), and GAPDH and antioxidant and metabolic biomarkers, characterizing the quality of human sperm. The results showed thatin vitrosupplementation of oregano significantly improves the mobility and antioxidant activities, without harmful effects on the integrity of the sperm's DNA, and that the selected concentration of oregano EO is nontoxic and may be considered a therapeutic alternative to heal sperm motility problems in asthenozoospermic patients.