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 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.