Type of hormone therapy may determine whether trans men continue to menstruate.

Study finds those using gel or cream were 10 times more likely to continue to menstruate after their treatment.

Taking testosterone can help transgender men gain “masculine” traits: hairier bodies, deeper voices, and no more menstruation. However, for some trans men, menstruation continues during such treatment, a symptom called “persistent menstruation.” The reasons for this are poorly understood by both researchers and clinicians.

A new study suggests the type of hormone replacement therapy (HRT) may be key. People using a gel or cream were 10 times as likely to continue to menstruate than those receiving injections, researchers report this month in the International Journal of Transgender Health. The work could better help those with gender dysphoria—the mismatch between a person’s gender identity and the one they were assigned at birth.

“Previous data has been mixed about the relative impact of dosage, serum testosterone levels, and route of administration on cessation of menstruation,” says Andrew Fisher, executive director of the Trans CARE program at the University of Chicago, who was not affiliated with the study. “These researchers’ contribution to the literature adds to a growing body of knowledge that will eventually allow clinicians greater ability to tailor [HRT] to individual needs.”

The new research is part of TRANSform, a trans-led study in Australia that tracks the health of trans people ages 16 or older, focusing on topics the community has questions about, such as gynecological care for trans men. Researchers led by sexologist Sav Zwickl and endocrinologist Ada Cheung of the University of Melbourne collected survey data from transmasculine people who were being followed for pelvic pain. The researchers examined data related to the type and length of HRT and experiences of menstruation before and after beginning the therapy. If participants were on HRT for more than 6 months or didn’t experience menstruation before starting the treatment, they were excluded from the study.

The team selected 401 participants ranging from ages 16 to 62, with a median age of 27. Five participants reported themselves as intersex, meaning they had a variation of sex characteristics that didn’t fall into typical male or female classifications.

The age that participants began taking HRT and menstrual regularity prior to taking HRT didn’t matter—what did was the way they took medication. Testosterone HRT is typically offered as either injections or as gels or creams rubbed onto the skin daily. Consistently taking testosterone usually results in stopping periods by the 6-month mark. Although nearly 23% of the participants continued to menstruate after 6 months of HRT, those using gel or cream were 10 times more likely to have persistent menstruation than those taking injections.

The findings could help trans people and their clinicians make decisions about their treatment plan, Cheung says. The work, she adds, is especially important for those interested in halting their menstrual cycle, which contributes to gender dysphoria and distress for many.

Still, more experiments will be needed to confirm the results, Cheung and Zwickl say. Future clinical studies should test the blood serum levels of testosterone rather than relying on survey responses, they say. “The survey nature of this means it’s self-reported,” Zwickl says. “For those taking testosterone for longer, it might mean recollections of when their period stopped and their dosages aren’t entirely accurate.”

Fisher also notes that Australia and Europe use long-acting testosterone, which is chemically different than the testosterone therapies used in other countries including the United States and parts of South America. As such, he says, it’s unclear whether the results of the new study apply globally.

Still, Zwickl says the study is a good first step. They say the high response rate to the survey and the rapport the research group has built with the trans community in Australia allowed the team to be able to conduct such a large study in the first place.

“The field of trans study is in its infancy,” Cheung adds. “It’s useful for trans people to have these studies, to know what to expect from their treatments. And hopefully we’ll continue to build our knowledge base in this area.”

Courtesy: Science

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