Systemic therapy with estrogen or estrogen with progestin has no effect on skin collagen in postmenopausal women. - Haapasaari,KM.; Raudaskoski,T.; Kallioinen,M.; Suvanto-Luukkonen,E.; Kauppila,A.; Laara,E.; Risteli,J.; Oikarinen,A. (Maturitas, 1997)