Every year, thousands of transgender men go through surgery for a hysterectomy with removal of the ovaries and fallopian tubes as part of their medical transition. Before that operation they have spent months or years on testosterone. What does the hormone do to the reproductive organs? A retrospective study published in the Journal of Clinical Medicine has placed 52 of those uteri and ovaries under the microscope to answer that question with data.
The question matters clinically. Testosterone is the backbone of gender-affirming hormone therapy in trans men, yet its effects on the endometrium, the ovary and the fallopian tubes had been described only incompletely. Understanding that impact helps clinicians interpret pathology reports for thousands of patients and decide whether any finding calls for a different follow-up.
The team reviewed cases from a tertiary referral centre between 2015 and 2019: transgender men operated on laparoscopically, with a median age of 25.5 years and a mean testosterone exposure of 16.1 months. Each surgical specimen was assessed for its histological pattern and, in the uterus, for oestrogen receptor (ER) and progesterone receptor (PR) expression by immunohistochemistry.
The most frequent finding was proliferative endometrium: it appeared in 78.8% of samples, ahead of inactive endometrium (17.3%), while only 3.8% showed atrophic endometrium. Endometrial polyps were found in 13.5% of cases. In the ovaries, a multifollicular pattern was predominant (90.4%), and paratubal cysts were detected in 63.5% of the fallopian tubes. No specimen showed premalignant or malignant lesions.
In other words, testosterone does not switch the reproductive tissue off the way it is sometimes assumed to. The endometrium keeps responding, and rather than vanishing, the hormonal signal remains detectable. ER expression was positive in every endometrial sample and in 92% of myometrial specimens, and PR expression was preserved in all the uterine tissues evaluated.
The authors stress the reassuring reading of the finding — no premalignant lesion appeared during the observed period — but also its limits, which deserve to be taken seriously: this is a retrospective study, with a modest sample, no comparison group, limited information on testosterone dose and route, and no long-term follow-up. No conclusion about future cancer risk can be drawn from it.
The work leaves a useful idea for the clinic: the reproductive organs of trans men on treatment are not silenced tissue, but tissue that stays alive and keeps responding to hormones. Documenting how it responds is the groundwork for monitoring gynaecological health in these patients with judgement rather than alarm.
Source: Journal of Clinical Medicine (2026). DOI: 10.3390/jcm15187304
