Background Androgenetic alopecia (pattern baldness) affects approximately half of all white-skinned men and women over the age of 40 years. Based on preclinical studies in mice in which topical fulvestrant (ICI182,780, an anti-oestrogen) caused telogen hair follicles to enter anagen, thereby causing hair growth, a topical formulation of fulvestrant was developed for the potential treatment of androgenetic alopecia. Objectives To evaluate the efficacy of fulvestrant solution in stimulating hair growth in men and postmenopausal women with androgenetic alopecia in two randomized, phase II, minoxidil- and/or vehicle-controlled studies. Methods One hundred and two white-skinned men aged 18-50 years with Norwood/Hamilton grades III, IIIv, IV, V or Va androgenetic alopecia received topical fulvestrant 70 mg mL(-1) solution, vehicle or minoxidil 2% solution twice daily for 16 weeks. Seventy postmenopausal women with Ludwig grade 1 or 2 androgenetic alopecia received topical fulvestrant 70 mg mL(-1) solution or vehicle twice daily for 16 weeks. The endpoints in both studies were hair density, cumulative hair thickness and hair growth rate, measured by TrichoScan analysis of digital images. Results There were no statistically significant differences favouring fulvestrant over vehicle at study end (day 113) for any of the efficacy parameters in men or women. Statistically significant differences in favour of minoxidil over fulvestrant were seen from day 57 onwards for hair density, cumulative hair thickness and hair growth rate in men. Conclusions These results indicate a lack of effect of topical fulvestrant in the treatment of subjects with androgenetic alopecia. The reasons for this lack of effect remain unclear.