Results of a prospective multi-center clinical trial show that a long-term, low-dose schedule of ethinyl estradiol and norethindrone acetate does not prevent age-related changes in skin surface. Researchers from Boston University revealed that there was no significant improvement in the skin structure after the end of a year long low-dose hormone therapy. The mean age of the 485 women enrolled in the trial was 53.6 years. Instead they recommended regular basic care through products like Renova that can save the skin from photo-damage.