Combined hormones linked to higher lumbar bone density in small observational study

A small observational study of 51 postmenopausal women found that adding testosterone to estrogen therapy was associated with a significant increase in lumbar spine bone mineral density, while estrogen therapy alone was not associated with a statistically significant increase at any measured site. The research, led by Sona Davis of the Keck School of Medicine at the University of Southern California, was scheduled for presentation at The Menopause Society’s 2026 Annual Meeting in San Diego on October 20–24, 2026. The reported finding concerns bone-density measurements, not evidence that combined therapy prevented fractures or produced broader skeletal benefits.

Investigators used dual-energy X-ray absorptiometry, or DEXA, to assess bone mineral density at the lumbar spine, femoral neck and hip. Measurements were taken at baseline, after participants had received estrogen therapy alone for at least one year, and after they had received estrogen plus testosterone for at least one year. The mean duration of estrogen-only therapy was 3.5 years, while the mean duration of combined estrogen and testosterone therapy was 3.1 years.

Across the study, participants were followed for an average of 4.1 years. The analysis compared T-scores at the three skeletal locations across these sequential treatment periods. Estrogen therapy alone did not produce a statistically significant increase in T-scores at the lumbar spine, femoral neck or hip.

In contrast, estrogen plus testosterone was associated with a significant increase in the lumbar spine T-score. The femoral neck and hip T-scores remained stable across both treatment periods, making the spine the only measured site where the researchers reported a significant increase after combined therapy. The release did not provide the numerical T-score changes, DEXA values, confidence intervals or other effect estimates, so the magnitude and precision of the observed association cannot be determined from the information supplied.

Based on the site-specific pattern, Davis and colleagues suggested that testosterone may have a synergistic effect with estrogen on trabecular bone, with the clearest measured association occurring at the spine. This was the investigators’ interpretation of the results rather than a separately demonstrated biological mechanism. The observational design and the sequence of estrogen-only and combined treatment mean that the findings establish an observed association, not a causal effect of adding testosterone.

Information about participant characteristics, adverse events and adherence was not included in the release. Bone density can decrease substantially during and after menopause as estrogen levels fall, and the release notes that women may lose 10% to 20% of their bone density in the first five to seven years after menopause. This rapid thinning raises the risk of osteopenia, described as low bone mass, and osteoporosis, characterized by weak, brittle bones that are prone to fracture.

Estrogen therapy has historically been prescribed to lower the risk of spine and hip fractures, while weight-bearing and resistance exercise, adequate calcium and vitamin D intake and hormone therapy are described as proven methods for protecting bone health. The present findings do not report a fracture outcome, and Davis said further research is needed to determine how testosterone could be used safely and effectively in individualized menopausal care. Stephanie Faubion, medical director of The Menopause Society, similarly emphasized the need for more studies exploring options that may help protect women’s bones during and after menopause.

Subject of Research: Bone mineral density during sequential estrogen and combined estrogen-testosterone therapy in postmenopausal women

Article Title: Combined estrogen and testosterone therapy increases lumbar spine bone mineral density

Article References: Combined estrogen and testosterone therapy increases lumbar spine bone mineral density. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: postmenopausal women, bone mineral density, estrogen therapy, testosterone therapy, lumbar spine, osteoporosis, menopause, DEXA, Combined, estrogen, testosterone, therapy