I will present the latest results from the Karlsruhe Tritium Neutrino Experiment (KATRIN). KATRIN probes the effective mass of electron anti-neutrinos via a high-precision measurement of the β-decay spectrum of tritium near its endpoint at 18.6 keV. In the first campaign, KATRIN established that the effective mass of neutrinos is <1.1 eV/c2 (90% CL). In the second physics campaign, the source activity was increased by a factor of 3.8 and the background was reduced by 25% compared to the first campaign. Combining the currently available KATRIN data, we find a new upper limit on the effective neutrino mass at <0.8 eV/c2 (90% CL).