Et forsøg på 2 uger med raske postmenopausale frivillige forsøgspersoner, behandlet med 20 μg ethinylestradiol dagligt, viste, at præmedicinering med 250 mg fulvestrant resulterede i en signifikant reduceret stimulation af det postmenopausale endometrium, sammenlignet med placebo, vurderet via ultralydsmålinger af endometriets tykkelse.
A 2-week study in healthy postmenopausal volunteers treated with 20 μ g per day ethinylestradiol showed that pre-treatment with 250 mg fulvestrant resulted in significantly reduced stimulation of the postmenopausal endometrium, compared to pre-treatment with placebo, as judged by ultrasound measurement of endometrium thickness