Adult Fracture Incidence and Bone Health Outcomes in Transgender Adults

confidence: medium · 3 sources

⚠
Working research — not a recommendation.

This page records what the evidence says a policy does, not what anyone should do about it. It has been synthesized from the cited sources but has not been independently reviewed.

What the evidence says

The sources on this page give a partial picture of bone outcomes in transgender adults on gender-affirming hormone therapy (GAHT). They cover bone mineral density (BMD) better than fracture. The fracture question that the topic names is mostly unanswered.

For transgender males on masculinizing hormone therapy, a meta-analysis cited in the Endocrine Society guideline (Hembree 2017) found no statistically significant difference in lumbar spine, femoral neck, or total hip BMD at 12 and 24 months compared with baseline. The source rates the quality of evidence as low. A 2025 review (Majumder) reaches a similar conclusion: GAHT does not negatively impact BMD in transgender men, and gonadectomy does not add risk to BMD if GAHT is given appropriately. That review gives no magnitude, and the claims do not say whether it rests on prospective data or on expert consensus.

For transgender females on feminizing hormone therapy, the same meta-analysis found a statistically significant increase in lumbar spine BMD at 12 and 24 months compared with baseline. The size of the increase is not quantified in the claims, and the source rates the evidence as low quality. Majumder states the mechanism. Testosterone and estrogen both contribute to bone health, and after gonadectomy estrogen is the sole hormone maintaining bone density. Majumder also states that suppressing testosterone without adequate estrogen replacement can significantly impact bone health. That claim gives no number, and the claims do not say whether it reflects measured outcomes or clinical judgment. It also stands as a risk condition, not a measured result. The mechanism statements are descriptive. The claims do not say whether they come from transgender-specific studies or from cisgender bone physiology.

On fracture, the evidence is thin. The Hembree meta-analysis reports "minimal information on fracture rates." A 2025 narrative review (Jacobson) says early evidence suggests estrogen-based and testosterone-based GAHT have a neutral to positive effect on bone health and fracture risk in transgender adults. That is a hedged, qualitative statement with no rate, ratio, or follow-up period. No claim here gives a fracture incidence for any group.

Where the evidence splits

No contradictions in the current sources.

Thresholds and dose-response

No threshold established in the current sources.

Open empirical questions

Findings

Masculinizing hormone therapy shows no measured effect on lumbar spine, femoral neck, or total hip BMD at 12 and 24 months in transgender males

confidence — direction: mediumconfidence — magnitude: mediumconsensus: thin — the two sources agree, but one is rated low quality and the other gives no basis for its conclusion.
mechanism
not established in the claims. Majumder states that testosterone and estrogen both contribute to bone health.
effect
no statistically significant difference from baseline at 12 and 24 months. No magnitude given.
conditions / moderators
low quality of evidence per the source. Participant age range not specified. Majumder adds that gonadectomy does not add BMD risk if GAHT is administered appropriately.

Feminizing hormone therapy increases lumbar spine BMD at 12 and 24 months in transgender females

confidence — direction: mediumconfidence — magnitude: lowconsensus: thin — one low-quality meta-analysis result, plus descriptive mechanism statements.
mechanism
estrogen maintains bone density, and after gonadectomy it is the sole hormone doing so (Majumder).
effect
increase in lumbar spine BMD versus baseline, statistically significant at 12 and 24 months. Magnitude not quantified.
conditions / moderators
low quality of evidence per the source. Age range not specified. Majumder states that suppressing testosterone without adequate estrogen replacement can significantly impact bone health.

Testosterone suppression without adequate estrogen replacement is described as impairing bone health in transgender women

confidence — direction: mediumconfidence — magnitude: lowconsensus: thin — one source, descriptive.
mechanism
testosterone and estrogen both contribute to bone health. After gonadectomy, estrogen is the sole hormone maintaining bone density.
effect
direction negative. Magnitude unquantified.
conditions / moderators
applies where estrogen replacement is inadequate. The claims do not say whether the wording reflects measured outcomes or clinical judgment.

Fracture incidence on GAHT is poorly measured, and a narrative review reports a neutral to positive effect on bone health and fracture risk

confidence — direction: mediumconfidence — magnitude: lowconsensus: thin — the evidence base is small, and the one directional statement is from a narrative review.
mechanism
not established.
effect
no fracture rates in the claims. Hembree reports "minimal information on fracture rates." Jacobson reports early evidence of a neutral to positive effect on bone health and fracture risk for estrogen-based and testosterone-based GAHT.
conditions / moderators
the review does not define "neutral to positive." The claims give no detail on differences across hormone regimens or populations.