Encyclopedia · antiandrogen
Alfatradiol
A weakly hormonal topical estradiol approved for pattern hair loss in Germany; in the one randomised comparison it only slowed loss while minoxidil grew hair.
What it is
Alfatradiol is the non-feminising mirror-image form of estradiol, applied to the scalp as a 0.025% solution. A German trial describes both alfatradiol and minoxidil as approved in Germany for women with pattern hair loss. Blume-Peytavi 2007 It is not FDA-approved, and availability elsewhere varies; we did not verify UK or EU status.
How it works
It is thought to act on androgen metabolism in the follicle. We found only lab work on this and attribute no results to it here.
What the studies show
- Versus minoxidil (103 women, randomised): minoxidil 2% for 12 months vs alfatradiol 0.025% for 6 months and then minoxidil. Minoxidil raised hair density and thickness; alfatradiol left them nearly unchanged at 6 months, which suggests it slows loss rather than regrowing hair, and switching to minoxidil then produced gains. Blume-Peytavi 2007
- Postmenopausal women (119, retrospective): topical finasteride 0.5% plus minoxidil 2% vs 17-alpha-estradiol 0.05% plus minoxidil 2%; both improved, with the finasteride combination better at 6 and 12 to 18 months. Rossi 2020
Side effects and safety
It was well tolerated in the German trial. The sources we reviewed did not address hormone absorption in postmenopausal women or use after breast cancer.
Bottom line
It is approved in some countries but shows little benefit beyond slowing loss. It is a gentle, low-risk option for women who cannot use other drugs, though minoxidil is better supported. Discuss with a doctor.
Studies 2
Blume-Peytavi U et al. Topical minoxidil versus alfatradiol in women with androgenetic alopecia. J Dtsch Dermatol Ges. 2007
Tested: minoxidil 2% for 12 months vs alfatradiol 0.025% for 6 months then minoxidil
Result: Minoxidil raised density and thickness; alfatradiol left them nearly unchanged at 6 months and switching to minoxidil then produced gains.
Read the study ↗Rossi A et al. Topical finasteride 0.5% vs 17alpha-estradiol 0.05% with minoxidil 2% in postmenopausal female pattern hair loss. Dermatol Pract Concept. 2020
Tested: topical finasteride plus minoxidil vs 17alpha-estradiol plus minoxidil
Result: Both improved; the finasteride combination was better at 6 and 12-18 months.
Read the study ↗Related
- FinasterideA prescription pill (and in some countries a scalp spray) that lowers DHT and is the best-proven drug for stopping male pattern hair loss.
- MinoxidilThe most widely used hair-growth treatment, available as a cheap over-the-counter lotion or foam and as a prescription tablet, with a mechanism that is still only partly understood.
- SpironolactoneA cheap blood-pressure pill that blocks androgen receptors and is the most widely used off-label hormonal treatment for women's pattern hair loss.
- Antiandrogen comparison for hair lossA side-by-side of the drugs, topicals and supplements that work on the androgen pathway, with who they were studied in and how strong the evidence is.