What fertility impacts does gender-affirming HRT have and can fertility be restored after stopping treatment?
Executive summary
Gender-affirming hormone therapy (GAHT) commonly suppresses gametogenesis: estrogen plus anti-androgens reduces spermatogenesis in transfeminine people and testosterone suppresses ovulation in transmasculine people, increasing risk of reduced fertility [1] [2]. Emerging clinical series show spermatogenesis can recover for some after stopping GAHT, but recovery is variable, not guaranteed, and depends on treatment type, duration, and individual biology; fertility preservation before GAHT remains the recommended strategy when biological parenthood is desired [3] [4] [5].
1. How GAHT affects reproductive biology: mechanism and clinical observations
Feminizing GAHT (estrogen with anti-androgens) suppresses the hypothalamic–pituitary–gonadal axis and commonly reduces or halts sperm production, sometimes producing testicular atrophy and abnormal semen parameters including low count, poor motility, or azoospermia [6] [2] [1]. Masculinizing therapy with testosterone typically suppresses ovulation and may alter ovarian histology, producing amenorrhea in most patients, though it does not uniformly eliminate the capacity to conceive [1] [7]. Clinical guidelines therefore counsel that hormone therapy may impact future fertility and that effects vary with dosage, duration, and whether gonadectomy has been performed [5] [8].
2. Evidence for recovery of fertility after stopping GAHT
Small, peer-reviewed series report recovery of spermatogenesis after GAHT cessation: de Nie et al. documented restored sperm production in nine transfeminine individuals, with some conceiving naturally 3–27 months after stopping hormones, and other case reports demonstrate sperm cryopreservation obtained weeks after cessation with adjunctive FSH/clomiphene in selected cases [3] [6] [9]. Systematic reviews and narrative analyses echo that while estrogen/anti-androgen therapy increases the proportion of abnormal or absent sperm, recovery after stopping treatment has been observed in multiple cohorts [2] [7]. Importantly, these data are preliminary, based on small samples and variable follow-up, so they indicate possibility rather than certainty [3] [9].
3. Limits, variability and timelines for restoration
Reported timelines for return of fertility are heterogeneous: anecdotal and guideline sources note recovery may occur as early as 3–6 months in some people but can take longer or fail to occur in others; some individuals required assisted medications or waited more than a year to detect viable sperm [10] [11] [12]. Factors that influence outcomes—age, baseline gamete quality, length and intensity of GAHT, prior puberty suppression, and concurrent medications—are incompletely characterized in existing research, and larger prospective studies comparing pre- and post-GAHT fertility are lacking [7] [2] [1]. Surgical removal of gonads (orchiectomy, oophorectomy, hysterectomy) causes permanent sterility and lies outside the scope of reversibility [1] [8].
4. Clinical guidance: preservation, counseling and assisted options
Because GAHT may impair gametogenesis unpredictably, expert centers and guidelines advise discussing fertility goals before starting hormones and offering fertility preservation—sperm, oocyte, embryo, or tissue cryopreservation—when desired and feasible [5] [12] [10]. If fertility is desired after GAHT, cessation of hormones can sometimes allow natural recovery; assisted reproductive techniques or gonadotropin therapies (e.g., FSH, clomiphene) have been used to retrieve sperm post-cessation in specific cases, but these interventions are not guaranteed and may require specialized care [3] [9]. Cost, access, and insurance gaps create disparities in who can preserve or restore fertility [8].
5. What remains uncertain and how to interpret current claims
The body of evidence shows that GAHT commonly suppresses fertility but—crucially—does not inevitably cause permanent infertility in all patients; small studies document reversibility of spermatogenesis for some individuals after stopping GAHT [3] [6]. Yet the existing literature is limited by small sample sizes, heterogeneous regimens, short or uneven follow-up, and potential selection bias toward people seeking fertility, so claims that GAHT always or never permanently sterilizes are unsupported by current data [2] [9]. Future large, prospective studies comparing pre-treatment baselines, stratifying by age and duration, and tracking reproductive outcomes are needed to refine counseling and policy decisions [2] [7].