During and after menopause the skin shows up clearly how the lack of estrogen affects tissues, and menopause can in fact be considered a "multisystemic" disorder of connective tissue. The low menopausal estrogen levels combined with age-related skin changes, accelerating skin aging. This affects both the epidermis and the dermis: fibroblasts not only become fewer, but they produce 30% less collagen, reflecting its metabolic decline. Estrogens act on collagen synthesis by directly stimulating fibroblasts. However, hormone replacement can prevent the postmenopausal loss of collagen--or eliminate it once it has started. The results of the Women's Health Initiative study drastically changed Italian gynecologists' prescribing habits. Natural products with estrogen-like activity are increasingly accepted, since they have good effects on collagen synthesis and/or inhibit collagenase activity, with a reassuring safety profile. This was confirmed by an in vitro study that assessed the tonic-trophic properties of two treatments on cultured skin fibroblasts. Cells were treated with resveratrol either alone or combined with NAC 10-100-1000 μM. There was a dose-related increase in the rate of cell proliferation and in inhibition of collagenase activity.