Estrogen Alone Doesn’t Curb Testosterone

Male-to-female transgender patients receiving estrogen alone won’t curb their testosterone production, a new study has found. New York State’s medical college conducted the study on one healthcare center where they found that about half of the patients receiving estradiol as part of hormone therapy experienced adequate testosterone suppression, even if accompanied by progestin says Matthew Leinung, MD, who was one of the researchers involved. These are two female hormones that act like estrogen and progesterone. Adding anti-antigens finasteride or spironolactone didn’t change anything.

Leinung made a presentation on their findings presented at the joint congress of the Endocrine Society and the International Congress on Endocrinology in Chicago. Leinung conceded, “I don’t know why I found what I found,” during his presentation. He went on to say, “I don’t have a good explanation because that’s not what the conventional wisdom is.”

There are lots of options when treating transgender patients, however, medical experts don’t know exactly which treatment is the ideal one. One thing all transgender medical experts agree on is that the hormone level has to be brought up to a normal level in the gender desired and that suppressing some hormone production in the patient is also crucial.

All the patients at his transgender clinic were evaluated by Leinung. Data from 82 patients out of more than 160 person sample was chosen for the study taking place between 2008 and 2013. 2008 was selected as this was when ethyl-estradiol was switched to oral estradiol. Leinung extracted out those who had reassignment surgery, were on Premarin, or hadn’t been taking estradiol long enough. He began giving them the hormones 4 mg doses of estradiol. 46% of the patients had significant testosterone suppression. Those that didn’t, the doses were upped to 6 mg. For those whom 6 mgs worked, the rate was still only 52%. Those who were still resistant and given finasteride to suppress their testosterone production actually saw the opposite come true, the body ramped up testosterone production.

Leuning, in his presentation, also mentioned research out of Maine Medical Center in Portland. That team, led by Lindsey Spratt, MD, and his colleagues, did find sufficient suppression in estrogen hormone therapy alone, which suggested against any added therapies until the physician got to see if the hormone therapy alone was sufficient.