Bone density loss in teenagers with gender dysphoria prescribed puberty blockers is mostly reversible with long-term gender-affirming hormone treatment in adulthood, Dutch doctors report in a landmark study.

While bone mineral accrual is suspended during puberty suppression with gonadotropin-releasing hormone (GnRH) agonists, their results from 75 transgender adults suggested this adverse effect was only temporary for those who continued to receive testosterone therapy.

For patients receiving oestrogen therapy, bone mineral density (BMD) returned to pre-puberty blocker levels for femoral neck and total hip, but not lumbar spine, the researchers said.

“These findings suggest that treatment with GnRH agonists followed by long-term [gender-affirming hormone treatment] is safe with regard to bone health in transgender persons receiving testosterone, but bone health in transgender persons receiving oestrogen requires extra attention and further study,” they wrote in JAMA Pediatrics.