A patented formula, PRX-T33:
 
TCA at 33% is a powerful peeling agent and without the addition of hydrogen peroxide would cause considerable frosting and peeling for several days. However, the addition of hydrogen peroxide allows the TCA to permeate beneath the epidermis to reach the dermis. At this level it stimulates both keratinocyte and fibroblast growth factor activity. The healing response begins and is accompanied by a visible improvement immediately after the treatment – but with no pain or downtime.