The most direct modern test of Kneipp hydrotherapy as a therapeutic method: a systematic review of 20 RCTs (N=4,247) covering disease therapy and prevention (Ortiz et al., BMJ Open, 2023). Of 132 comparisons, 46 favored Kneipp hydrotherapy, 81 showed no difference, and 5 favored the control condition; no meta-analysis was possible because of high clinical heterogeneity across study designs and outcomes, and risk of bias was rated unclear in most domains. The review’s own verbatim conclusion: “Although RCTs on Kneipp hydrotherapy seem to show positive effects in some conditions and outcomes, it remains difficult to ascertain treatment effects due to the high risk of bias and heterogeneity of most of the considered studies. Further high-quality RCTs on Kneipp hydrotherapy are urgently warranted.” This is an “insufficient evidence” finding, not a demonstrated broad benefit and not a hard-endpoint (mortality, lifespan, disease-incidence) result — the current-day status of the intervention’s original 1886 claim.