Koohestanidehaghi Y, Torkamanpari M, Shirmohamadi Z, et al. - As reactive oxygen species (ROS) may adversely affect sperm function, researchers here examined how cysteine and glutamine as effective antioxidants affect human sperm parameters under vitrification. They used 20 normozoospermic samples and subjected them to a vitrification process and cysteine (5 and 10 mM) and glutamine (10 and 15 mM). In statistical analyses, decrease in motility, mitochondrial membrane potential and DNA damage was identified in the vitrified groups with cysteine 5, 10 mM and glutamine 10, 15 mM separately. Overall results demonstrated no significant influence of a specific concentration in cysteine and glutamine on sperm parameters compared with other concentrations. They suggest the potential of both amino acids in improving the harmful effects of freezing on sperm parameters.