Hydrogenized water is known to have protective effects on cells and tissues, mainly through its antioxidant activities. Here we examined the protective effects of a commercial source of hydrogenized water on cultured human brain cells. Hydrogenized water was able to protect brain cells from oxidative stress and glutamate toxicity. At H 2 concentrations above 0.01 mM the glutathione levels increased in cultured brain cells. The level of glutathione rose from approximately 500 to approximately 850 μM at the maximum dose of hydrogenized water with an EC 50 of approximately 0.030 mM. Hydrogenized water was also able to enhance the signaling pathway for oxidative stress response mediated by Nrf2 (Nuclear factor erythroid 2 like factor). Treatment of cells with hydrogenized water at concentrations above 0.01 mM H 2 induced activation of Nrf2 (EC 50 approximately 0.05 mM). Hydrogenized water was also able to protect brain cells against glutamate toxicity. Using a DNA damage response element, (γH2AX, to monitor the damage of glutamate toxicity we found that concentrations of H 2 above 0.01 mM protected cells from glutamate damage with an EC 50 of approximately 0.05 mM H 2. These in vitro results demonstrated that hydrogenized water can protect brain cells against common types of damage from oxidative stress and glutamate toxicity.