The best evidence for efficacy from adequately designed randomized controlled trials (RCTs) is available for Coccinia indica and American ginseng. Chromium has been the most widely studied supplement. Other supplements with positive preliminary results in
Traditional Chinese Medicine (TCM), Traditional Ayurvedic Medicine (TAM), European Phytotherapy, Naturopathy, Eclectic Medicine, Native American Medicine, Arabic medicine and African Traditional Medicine, and many others...