Novel N-methylated ebselenamine antioxidants were prepared from the corresponding diselenides with iodomethane. All ebselenamines showed excellent chain-breaking and glutathione peroxidase (GPx)-like activities. They could also inhibit lipid peroxidation much more efficiently than α-tocopherol. They could also mimic the functions of the GPx-enzymes nearly two times better than ebselen in the coupled reductase assay. Also, they were found to scavenge the ROS produced at low concentration (10 μM) with low toxicity effects and could have therapeutic potential against autoxidation. It is anticipated that these compounds could potentially be used against several diseases caused by autoxidation, and thus provide protection from cell death to mammals.