Abstract: Insulin or a peroxisome proliferator-activated receptor (PPAR) agonist provides reliable and effective prevention of scarring in human skin, or at least a reduction in the severity of scarring. The application of insulin or the PPAR agonist to wounds topically or by local injection is particularly advantageous since it simultaneously reduces/prevents scarring while enhancing re-epithelialization of the wound and thus provides a dual action wound healing treatment. The present invention accordingly provides a highly effective prophylactic treatment for any individual suffering tissue trauma to reduce and/or prevent normal and/or pathological scarring.