Chronic use of sildenafil (Revatio, Viagra) improves insulin sensitivity in prediabetics, according to a new study. In a randomized, double-blind, placebo-controlled study, subjects were randomized to treatment with sildenafil 25 mg three times a day or matching placebo for 3 months. Twenty-one subjects completed each treatment arm. After 3 months, the insulin sensitivity index was significantly greater in the sildenafil group compared to the placebo group (P = 0.049). Sildenafil also decreased the urine albumin to creatinine ratio, an effect that persisted 3 months after discontinuation. Further study is needed to see if sildenafil can prevent diabetes in high-risk individuals, but these early results are promising (J Clin Endocrinol Metab doi: 10.1210/jc.2015-3415).