Document Type



R-alpha lipoic acid (R-ALA) supplementation improves blood glucose in diabetic animals, but there have been no long-term clinical trials in humans testing its use for glucose control (HbA1c). This double-blind study pre-/post-test control group (PL) design sought to determine the effect of R-ALA on HbA1c. Twenty type-2 diabetics were randomly assigned to 200 mg capsules of R-ALA (n=13; 8M 5F) or PL (n=7; 2M 5F) 3 times daily, 30 minutes before meals (600 mg total) for 91 days. Samples were obtained for HbA1c at baseline and day 91. No significant differences between R-ALA and PL groups were found at baseline or day 91. However, three distinct reactions to the supplement were noted. The first group (n=3) responded to R-ALA with a >25% drop in HbA1c range from 6.1-12.5 to 6.2- 9.0 mg/dL and/or halved their anti-diabetic medication. The second group (n=5) had no change in HbA1c. The third group (n=5) had changes in medication or concurrent chronic adverse events that should have raised HbA1c, but did not beyond that of the placebo. Conclusions: Three months of R-ALA supplementation may lower HbA1c in a small number of individuals. However, to further confirm these findings, larger studies of longer duration are needed.



Publication Date


Original Citation

Journal of Complementary and Integrative Medicine. Volume 6, Issue 1, DOI: 10.2202/1553-3840.1297, October 2009

Legacy Department

School of Family, Consumer and Nutrition Sciences






De Gruyter



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