The invention discloses compositions that effectively reduce and stabilize glucose levels in the blood of mammals, specifically in pre-diabetic patients and patients with type 2 diabetes mellitus (T2DM). Composition 1 (Comp1) reinforces efficacy of Mg salt to reduce glucose level by the combination of Mg salt with anti-inflammatory agents konjac-glucomannan (KGM), vitamin C and alpha-lipoic acid (.alpha.-LA). Composition 2 (Comp2) provides safety for chromium picolinate (CrPic) by the combination of CrPic with anti-inflammatory agents KGM, vitamin C and .alpha.-LA that inhibits oxygen radicals. Compositions may optionally include cinnamon extract (CE) or another insulinogenic nutraceutical agent, American ginseng (AG), Uncaria tomentosa, Uncaria guianensis and Urtica dioica.