For a trans man who has been on testosterone for years and is thinking about fertility, the question is very concrete: are there still eggs in there, and in what state does treatment find them? The answer usually given in clinic is reassuring but imprecise, because data on the direct effect of the androgen on the human ovary are scarce. Now a team from the Institute of Cell Biology and the Centre for Reproductive Health at the University of Edinburgh, with collaborators from hospitals in Edinburgh and Glasgow, publishes an analysis of ovarian tissue from transgender men who had been on testosterone for a long time.
Eight ovaries against eight controls
The authors obtained whole ovaries from eight transgender men who underwent oophorectomy after long-term testosterone therapy (mean age 27.6 years) and compared them with ovarian cortical biopsies from eight healthy women of similar age obtained during caesarean sections. They analysed the composition of the stroma —the supporting tissue surrounding the follicles— measuring collagen, elastin and stromal cell density, and related it to the density of non-growing follicles.
A stiffer ovary, but the same reserve
- Testosterone-exposed stroma showed a more fibrotic composition: more collagen and less elastin, raising the collagen-to-elastin ratio and pointing to greater intrinsic tissue rigidity.
- Stromal cell density was significantly higher, consistent with stromal hyperplasia.
- By contrast, non-growing follicle density was comparable to controls. In other words, the ovarian environment changes, but the resting egg reserve was not reduced.
The stroma plays a supporting role: it wraps around the follicles and provides the microenvironment they need to stay quiescent or to begin growing. That this microenvironment becomes stiffer and more cellular, while the pool of quiescent follicles holds steady, is the central observation of the work.
Why it matters — and what it does not say
The authors themselves note the main limitation: the controls come from caesarean-section tissue, not from healthy ovaries of non-pregnant women, which may introduce differences in the stroma. Add to that the small sample size. The result should therefore not be read as a guarantee about future fertility, but as a biological clue: testosterone appears to remodel the ovary’s supporting tissue without depleting the follicle reserve outright.
This is relevant for anyone considering fertility preservation or pausing hormone therapy to pursue a pregnancy, and for the teams advising those decisions. The authors call for more research into the functional significance of these changes in transgender men who are considering carrying a pregnancy or cryopreserving their gametes.
The study does not address the basis of gender identity or the cause of dysphoria: it describes the effect of a hormone treatment on one specific organ, the ovary, in people already receiving it. It does add a missing link to understanding what happens to reproductive tissue under sustained testosterone.
Source: The ovaries of transgender men indicate effects of testosterone treatment on the ovarian stroma without changes in non-growing follicle density. Bailie E, Grosbois J, Hawthorn R, et al. Molecular Human Reproduction 2026;gaag061. DOI: 10.1093/molehr/gaag061.
Article published at dosier.es. Image generated with artificial intelligence (marta ai → marta.syf.es).
