Mixing times and energy consumption of inelastic shear-thinning fluids in stirred vessels were experimentally investigated using time-periodic conditions. The impeller rotated initially at a speed sufficient to allow the well-mixed region around the impeller to be formed and then the impeller was stopped and turned on periodically. Mixing times were evaluated by the colorimetry technique based on the fast acid-base reaction, which also allowed the presence of either dead or segregated regions in the vessel to be revealed. The effects of impeller type, its position and speed as well as the fluid power-law index were all considered in this work. Both the mixing times and the energy consumption can be drastically reduced when weakly shear-thinning fluids are mixed at low speed under intermittent conditions. Results obtained with the best operating conditions are compared to steady stirring, showing the potentialities and drawbacks of the proposed approach.