N-acetylcysteine (NAC), a cysteine pro-drug and glutathione precursor has been used in therapeutic practices for several decades, as a mucolytic agent and for the treatment of numerous disorders including paracetamol intoxication. There is a growing interest concerning the beneficial effects of NAC against the early stages of type-2 diabetes development. Nevertheless, the mechanisms underlying the therapeutic and clinical applications of NAC are not fully understood. In this review we aimed to focus on the protective effects of NAC against insulin resistance.