['It is known that exposure to severe hypobaric hypoxia induces changes of reactive oxygen species (ROS) and antioxidant systems. L-carnitine, a natural compound, has an antioxidant effect and decreases lipid peroxidation. The aim of this study was to investigate the protective effects of L-carnitine treatment on oxidative stress induced by exposure to hypobaric hypoxia.', '30 male Wistar rats were divided into 3 equal-size groups: 1st group - a control group, kept in normoxic conditions; 2nd group - rats exposed to hypobaric hypoxia in the barochamber (simulated high altitude equivalent to 5500 meters) for a 14-day placebo; 3rd group - rats exposed to hypobaric hypoxia for 14 days and treated with L-carnitine (L-carnitine, 100 mg/kg) every day. After 14 days, the serum levels of lipid peroxides expressed by the value of malondialdehyde (MDA), and the serum levels of carbonylated proteins (CP), glutathione (GSH) and donor hydrogen ability (DHA) were determined for all rats.', 'The results indicated an increase in MDA and CP levels, after the exposure to hypobaric hypoxia. L-carnitine significantly decreased (p <0.05) the levels of the MDA and CP and significantly increased (p <0.05) the serum antioxidant capacity: glutathione and DHA.'] Does [ L-carnitine decrease oxidative stress induced by experimental hypobaric hypoxia ]?