[en] BACKGROUND: The endocrine control of sebaceous follicles is complex in women. During aging, a decline in sebum output is often experienced. However, some women report increased seborrhea after the menopause. OBJECTIVE: In this study, the follicular reservoir function was studied during the first decade following the menopause. METHODS: Four evaluations were made at 3-week intervals in two parallel age-matched groups of 50 postmenopausal women receiving hormone replacement therapy (HRT) or not. The Sebumeter served to measure the casual sebum level and the sebum excretion rate on the forehead. In addition, a Visioscan equipped with an ultraviolet-recording camera was used with and without lipid-sensitive tapes interposed between the camera and the skin surface. Follicular openings and sebum pore patterns were studied by image analysis. RESULTS: There was enormous diversity among individual values of sebum output at the skin surface. In untreated women, a significant decline in sebum excretion rate accompanied by an increase in both the sebum replacement time and the mean pore size were evidenced during the first decade after the menopause. The sebum excretion rate and casual level showed a wide range of interindividual differences early after the menopause. These physiological changes were less prominent in women receiving HRT. CONCLUSION: Postmenopausal aging affects the sebum production, but HRT does not significantly control the complex process of seborrhea. However, HRT mitigates the progressive enlargement of the openings of the sebum follicular reservoir.