Related Experiment Video
Updated: May 17, 2026

Establishment of Rat Models Mimicking Gender-affirming Hormone Therapies
Published on: January 10, 2025
[Hormone replacement therapy: practical aspects]
C Sonigo1, G Dray, N Chabbert-Buffet
1INSERM 693, université Paris-Sud, 63 rue Gabriel-Péri, Le Kremlin-Bicêtre cedex, France.
Abstract:
Menopause is a total follicular depletion leading to menstruation cessation. Climacterics symptoms are linked to estrogen decrease. Hormonal replacement therapy (HRT) was developed in 1940s in order to control these signs and to improve women's quality of life. In United States, conjugated equine estrogen, first estrogens developed, are the most common. In France, customs are different with the transdermic estrogen use. The progesterone use is also different between both countries: in USA, medroxyprogesteron acetate is the most common, whereas this treatment does not exist anymore in France. Indeed, lot of different progestagen is available in France: progesterone, dydrogesterone others progestin. Publication of randomized trials, as the Women's Health Initiative, had shown a long-term unfavorable HRT risk/benefit ratio, as prescribed in USA. These studies have led to prescription modification. Due to these results, recent trials, closers to French customs, allowed a new evaluation of HRT risk/benefit ratio. Today, clinical practices are based on these results and new trials are necessary.
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