Rehmannia for Blood Sugar Regulation

Research suggests that Rehmannia and its active compounds — particularly catalpol and various root extracts — may support blood sugar regulation and protect against diabetes-related complications, based primarily on animal and cell-based studies. Studies indicate that Rehmanniae Radix extracts lowered fasting blood glucose and improved insulin resistance in diabetic rat models, with proposed mechanisms including enhanced glucose uptake in the liver via GLUT1, activation of TRPV1, suppression of SCD1, and modulation of AMPK signaling pathways. A 2023 systematic review and meta-analysis of 12 animal studies found that catalpol specifically showed promise in protecting kidney function in diabetic nephropathy models, and a 2024 animal study on catalpol alone showed modest blood sugar reductions at lower doses, though a higher dose showed no benefit and worsened LDL cholesterol, and catalpol was outperformed by a standard diabetes medication. The overall body of evidence is limited to preclinical research — predominantly rodent models and cell cultures — with no human clinical trials identified among these studies, meaning findings should be interpreted cautiously and cannot be directly applied to human health outcomes.