Insulin function and the abnormalities associated with insulin resistance, may have a major role in preventing type 2 diabetes and, in the long-term, diabetes micro- and macrovascular complications. Carnitine is involved in lipids and carbohydrates metabolism and acetyl-L-carnitine(ALC), an intramitochondrial carrier of acylic group, may modulate cell fuel substrate utilization. Studies found that carnitine may improve insulin sensitivity and glucose disposal in healthy subjects and in patients with type 2 diabetes. A recent study also found that a primed constant infusion of acetyl-L-carnitine (ALC) may increase glucose utilization in type 2 diabetic patients, possibly restoring the glycogen synthase activity.