Testosterone has historically been considered a ‘male’ sex hormone, but that outdated notion may be preventing better treatments for postmenopausal women. Along with estrogen, the ovaries also produce testosterone, and this overlooked androgen could be part of the reason why bone is lost in older age. A small new study has found that adding testosterone to hormone replacement therapy may protect bone density more than estrogen on its own.
The findings are not yet published in a peer-reviewed paper, but they were presented at the 2026 Annual Meeting of The Menopause Society in San Diego this October. “Menopausal patients deserve treatment options that reflect the complexity of their health needs, including long-term bone health. We hope that our findings can encourage further research into how testosterone could be used safely and effectively as part of individualized menopausal care,” says lead author Sona Davis from the University of Southern California.
Estrogen Is Not the Only Culprit in Bone Loss
After menopause, when menstruation ceases, estrogen levels drop rapidly, and this is a major cause of weak, porous bones in older age. For decades, estrogen therapy has been used to protect against bone loss, increasing bone density and reducing fractures in both the spine and the hip. But testosterone can also decrease with age, and recent studies have found evidence that it is linked to bone health, not just in older men but in women too.
In 2022, a population-based study among females aged 40 to 60 years in the US found that testosterone levels were positively associated with bone mineral density in the lumbar spine. “According to the literature, it is basically clear that testosterone promotes bone mineral density in males, but by contrast, evidence for females is sparse and controversial,” the authors wrote at the time. Today, testosterone replacement therapy is best established as a bone treatment for men with low testosterone levels, but preliminary evidence suggests this therapy may work for women too.
What the New USC Study Found
To see if testosterone can improve estrogen therapy’s benefits, the USC team analyzed health outcomes of 51 postmenopausal participantswho were each prescribed hormone therapy at the same private hospital. All participants tried two therapies, each for at least a year and typically for several years. One involved just estrogen, and the other involved both estrogen and testosterone. X-ray scans measured bone mineral density at the start of the trial, and then again one year into each type of therapy.
Surprisingly, researchers found that estrogen therapy alone kept bone density stable, but did not significantly increase it at any location examined: not the lumbar spine, femoral neck, or hip.
“These findings suggest that testosterone may exert a synergistic effect with estrogen on trabecular bone, particularly at the spine, and may offer enhanced skeletal benefit beyond estrogen alone,” the authors conclude in their conference abstract.
It is unclear whether these changes in spinal density are sufficient to reduce fracture risk, which is the main measure of success in osteoporosis treatment. But the results support the idea that testosterone may have a role in protecting bone health as we age.
Growing Evidence for Testosterone in Women
In 2023, researchers at Monash University in Australia launched a trial to test this, noting that “there is some evidence that the addition of testosterone to estrogen replacement therapy might prevent bone loss and restore sexual function in women with early menopause.”
That same year, a small trial found that testosterone therapy alone or in combination with low-dose estrogen therapy can improve spine and hip bone density. Larger and longer trials are still needed, and these studies need to demonstrate reductions in fracture risk, not just increases in bone density.
Knowing these clinical outcomes is key to evaluating risks and benefits of hormone replacement therapy, which should be carefully weighed by clinicians and patients. For now, it is important to recognize that testosterone is an essential hormone for the female body, impacting everything from the brain to the heart. How it affects bones is a mystery we are only just starting to crack.
Q&A
Q: Does estrogen therapy alone increase bone density after menopause?
A: In this small study of 51 women, estrogen alone kept bone density stable but did not significantly increase it at the spine, hip, or femoral neck after one year.
Q: What did adding testosterone do?
A: Estrogen plus testosterone increased bone mineral density scores for the lumbar spine, suggesting a synergistic effect on trabecular bone, which is the spongy bone inside vertebrae.
Q: Does higher bone density mean fewer fractures?
A: Not necessarily. The study measured bone density, not fracture risk. Preventing fractures is the main goal of osteoporosis treatment, so larger trials must confirm clinical benefits.
Q: Is testosterone therapy safe for postmenopausal women?
A: Safety was not the focus of this abstract. Hormone therapy risks and benefits must be individualized. More peer-reviewed research is needed before routine use.
FAQ
1. Who led the study and where was it presented?
Lead author Sona Davis from the University of Southern California, presented at the 2026 Annual Meeting of The Menopause Society in San Diego. Findings are not yet peer-reviewed.
2. How was the study designed?
51 postmenopausal women at one private hospital each tried two therapies for at least a year: estrogen alone, and estrogen plus testosterone, with bone density measured by X-ray at baseline and after one year.
3. What is the main takeaway?
Estrogen alone stabilized bone density, while estrogen plus testosterone increased lumbar spine density, suggesting testosterone may offer added skeletal benefit beyond estrogen alone.
4. Is testosterone already used for bone health?
It is established for men with low testosterone. For women, evidence is still sparse and controversial, though population studies link higher testosterone to higher spine bone density in women aged 40-60.
5. What research is next?
Larger, longer randomized trials, like the Monash University trial launched in 2023, need to test whether adding testosterone prevents bone loss and reduces fractures, and also evaluate safety.
Disclaimer: This article is for informational purposes only and summarizes a conference abstract that has not yet been peer-reviewed. It does not constitute medical advice. Hormone replacement therapy has risks and benefits that must be discussed with a qualified healthcare professional. Do not start or change hormone therapy without medical guidance.
