In people who have vaginas and uteruses, various physiological processes of the reproductive system (including ovulation, menstruation, and maintenance of vaginal tissue) are usually maintained by oestrogen and progesterone, which are usually produced by the ovaries. Masculinising hormone treatment can halt these physiological processes, because testosterone inhibits the production of oestrogen and progesterone by the ovaries. This can result in cessation of menses, vaginal atrophy, and infertility.
Testosterone inhibits the production of oestrogen and progesterone by the ovaries. This often results in periods becoming lighter, less frequent, and eventually stopping.
The timescale for cessation of menses with testosterone is variable. However, a recent study on 114 trans men who commenced testosterone found that periods stopped within 6 months for 55% of participants and within 12 months for a further 32% of participants (Ahmad and Leinung, 2017). Hence, cessation of menses can be expected to occur 6 to 12 months after commencing testosterone.
If your periods are continuing despite your testosterone level being within the desired range, other medical interventions are available which can help achieve cessation of menses. These may include the progesterone-only pill, a gonadotropin-releasing hormone analogue (GnRHa), or an intrauterine device (IUD).
The suppression of oestrogen production by testosterone leads to changes in the vaginal tissue. These include decreased vaginal lubrication and thinning of the vaginal skin, which can result in irritation and pain, especially during penetrative sexual activity.
A recent study found that over 60% of trans men who take testosterone exhibit symptoms associated with vaginal atrophy (Tordoff et al., 2023). This can occur within 6 months of commencing testosterone.
Vaginal atrophy can be treated with topical oestriol cream (Ovestin® 0.1%), which is applied to the vagina and can help to maintain vaginal health without producing any systemic feminising changes.
Taking testosterone can suppress egg production, but different people may be affected in different ways. Unfortunately, it is not possible to predict exactly how testosterone will affect your fertility.
Although we know that testosterone can stop menstruation and ovulation in the short-term, there is no consistent evidence about its long-term effects on fertility (Cheng et al., 2019). While one study showed that ovaries of trans men who take testosterone exhibited changes in the tissues (Grynberg et al., 2010), another study showed that the ovaries of trans men who take testosterone remained healthy (de Roo et al., 2017).
Some people on testosterone do go on to conceive and give birth to children. However, given the uncertainty, it is best to consider the possibility that your fertility could be affected by testosterone. If you wish to avoid pregnancy and are sexually active with someone who is capable of producing sperm, it is advised that you use a method of contraception.
If you do become pregnant while on masculinising hormone treatment and wish to keep the baby, then it is advised that testosterone is stopped while you are pregnant. This is because testosterone can be associated with harm to the baby (Thornton and Mattatall, 2021).
Trans men and transmasculine people who have not undergone oopherectomy (removal of the ovaries) can store eggs at a specialist clinic. This is a medical procedure that requires hormonal stimulation for egg retrieval. Given that testosterone can suppress egg production, fertility preservation through egg storage is more likely to be successful if the sample is produced before commencing masculinising hormone treatment. If you have already commenced masculinising hormone treatment, then it may still be possible for you to produce eggs for fertility preservation, but there is a theoretical possibility that the chance of success may be decreased.
Hormonal stimulation for egg retrieval can take at least two weeks and results in temporarily increased oestrogen during this period. We are aware that this may worsen gender dysphoria for some people.
Ahmad, S., and Leinung, M. (2017). "The Response of the Menstrual Cycle to Initiation of Hormonal Therapy in Transgender Men". Transgender Health, 2(1): 176–179.
Cheng, P. J., Pastuszak, A. W., Myers, J. B., Goodwin, I. A., and Hotaling, J. M. (2019). “Fertility Concerns of the Transgender Patient”. Translational Andrology and Urology, 8 (3): 209–218.
de Roo, C., Lierman, S., Tilleman, K., Peynshaert, K., Braeckmans, K., Caanen, M., Lambalk, C. B., Weyers, S., T’Sjoen, G., Cornelissen, R., and de Sutter, P. (2017). “Ovarian Tissue Cryopreservation in Female-to-Male Transgender People: Insights into Ovarian Histology and Physiology After Prolonged Androgen Treatment”. Reproductive Biomedicine Online, 34 (6): 557–566.
Grynberg, M., Fanchin, R., Dubost, G., Colau, J. C., Brémont-Weil, C., Frydman, R., and Ayoubi, J. M. (2010). “Histology of Genital Tract and Breast Tissue After Long-Term Testosterone Administration in a Female-to-Male Transsexual Population”. Reproductive Biomedicine Online, 20 (4): 553–558.
Tordoff, D. M., Lunn, M. R., Chen, B., Flentje, A., Dastur, Z., Lubensky, M. E., Capriotti, M., and Obedin-Maliver, J. (2023). "Testosterone use and sexual function among transgender men and gender diverse people assigned female at birth". American Journal of Obstetrics and Gynecology, 229(6): 669.