This study evaluated whether a chemical skin biostimulator containing ammonium trichloroacetate, homocysteic acid, phytic acid and citric acid can improve signs of photoaged skin in women with mature skin. Twenty-five women received four treatment sessions two weeks apart, followed by a home-care skincare regimen. Skin firmness, wrinkles, skin texture, hydration, sebum production and, in participants with hyperpigmentation, skin tone uniformity were measured before treatment and at 2 and 12 weeks after the treatment series to determine whether the biostimulator produces lasting improvement in photoaged skin without the downtime associated with traditional chemical peels.