Johrei is an alternative healing practice that involves the channelling of a purported universal healing energy to influence the health of another person. Despite little evidence to support the efficacy of such practices, the use of such treatments is on the rise. American investigators assessed cultured human cancer cells for potential responsiveness to Johrei treatment from a short distance. Johrei treatment was delivered by practitioners who participated in teams of two, alternating every half-hour for a total of 4 h of treatment. The practitioners followed a defined set of mental procedures to minimise variability in mental states between experiments. An environmental chamber maintained optimal growth conditions for cells throughout the experiments. Computerised time-lapse microscopy allowed documentation of cancer cell proliferation and cell death before, during and after Johrei treatments. Comparing eight control experiments with eight Johrei intervention experiments, no evidence of a reproducible cellular response to Johrei treatment was found.