Gender-affirming healthcare is essential for the well-being of transgender and gender-diverse individuals. As more people access gender-affirming hormone therapy (GAHT), it becomes increasingly important to understand how these treatments affect long-term health — including bone density, a critical aspect of overall health and mobility.
While GAHT offers transformative benefits, it also interacts directly with the hormones responsible for building and maintaining strong bones. This blog unpacks the science behind bone health during gender modification, the risks that may arise,G and practical steps for protecting skeletal strength throughout one’s transition journey.
- Hormonal Influence on Bone Health
Bones are living tissues that respond continuously to hormonal signals. Estrogen and testosterone — the primary hormones involved in gender-affirming therapy — play essential roles in bone development and preservation.
Estrogen
- Helps regulate the bone remodelling cycle
- Reduces bone resorption (breakdown)
- Supports the maintenance of bone mineral density (BMD)
Transgender women (AMAB – assigned male at birth) who undergo estrogen therapy typically maintain healthy bone density if hormone levels stay within therapeutic ranges. Low estrogen levels — often due to inconsistent treatment, missed doses, or inadequate monitoring — can however increase the risk of bone loss.
Testosterone
- Stimulates bone formation
- Increases muscle mass, which indirectly strengthens bones
- Supports peak bone mass development in adolescence
Transgender men (AFAB – assigned female at birth) who receive testosterone therapy generally preserve or even increase bone density. However, inadequate dosing, suppressed estrogen levels, or lapses in treatment may compromise skeletal health.
- Age as a Critical Factor
Bone health is significantly influenced by the age at which hormone therapy begins.
Adolescents
The teenage years are crucial for achieving peak bone mass, which largely determines future osteoporosis risk.
- If GAHT starts before peak bone mass is reached, hormone levels must be carefully managed to support continued bone development.
- Puberty blockers, while beneficial for aligning physical development with gender identity, can temporarily slow bone mineral accrual. Once GAHT begins, most adolescents regain expected bone density, but monitoring is essential.
Adults
Adults who begin GAHT after their bones have fully developed tend to maintain stable BMD, provided hormone levels remain adequate. Risks increase if:
- Treatment is delayed or inconsistent
- Surgical removal of gonads occurs without proper hormone replacement
- Coexisting medical conditions contribute to bone loss
- Transitioning and Bone Loss Risks
Although many people on GAHT maintain healthy bone density, certain factors can increase the risk of bone loss or future osteoporosis:
Potential Risk Factors
- Insufficient estrogen or testosterone levels
- Stopping or interrupting hormone therapy
- Inadequate vitamin D or calcium intake
- Smoking, alcohol overuse, or a sedentary lifestyle
- Low body weight
- Prolonged use of puberty blockers without follow-up monitoring
- Surgical changes that reduce the body’s natural hormone production
Long-term studies show that bone density may decrease when hormones are not adequately replaced after gonadectomy (e.g., orchidectomy or oophorectomy). This makes regular medical supervision essential.
- Preventive Measures for Strong Bones During Transition
Individuals undergoing gender modification can take proactive steps to maintain healthy bones over their lifetime.
Regular Bone Density Scans
- DXA scans are recommended for:
- Individuals with a history of low hormone levels
- Those on puberty blockers
- Anyone post-gonadectomy without consistent hormone replacement
- People over 50 or those with multiple risk factors
Nutritional Support
- Adequate calcium (1,000–1,200 mg/day depending on age)
- Sufficient vitamin D (600–800 IU/day or as prescribed)
- A balanced diet with protein, fruits, and vegetables for optimal bone turnover
Weight-Bearing Exercise
Activities that build bone strength:
- Walking
- Resistance training
- Jogging
- Climbing stairs
- Pilates or yoga for balance and stability
Lifestyle Adjustments
- Stop smoking
- Limit alcohol
- Maintain a healthy weight
- Prioritise sleep and stress management
- Current Research: What We Know and What’s Emerging
Growing research highlights the complex relationship between GAHT and bone health. Key findings include:
- Transgender men tend to maintain or improve BMD while on adequate testosterone therapy.
- Transgender women maintain bone density with well-managed estrogen therapy but may lose BMD if levels drop too low.
- Adolescents on puberty blockers experience temporary reductions in bone density, but most recover after starting GAHT.
- Studies are exploring:
- The long-term effects of GAHT beyond 20–30 years
- Individual differences based on genetics and lifestyle
- New treatment options that may help optimise bone outcomes during transition
Researchers emphasise that the greatest threat to bone health is undertreatment or inconsistent hormone replacement, not the therapy itself.
- Intersectionality and Access: A Hidden Risk Factor
Bone health outcomes during gender modification are influenced not only by biology but also by social determinants of health.
Factors That Can Affect Bone Health Access:
- Limited financial resources
- Lack of insurance coverage for GAHT or bone scans
- Geographic distance from specialised clinics
- Discrimination or bias within healthcare systems
- Limited access to nutritious food or exercise facilities
These barriers mean that some transgender individuals may struggle to maintain the monitoring and preventive care needed for optimal bone health. Improving equitable access to care is crucial.
- Personal Stories: Lived Experiences Behind the Science
Personal narratives highlight the emotional and practical realities of managing bone health during transition.
Alex’s Story (Trans Woman, 34)
“I didn’t realise how much estrogen levels could affect my bones until my doctor found early signs of osteopenia. Once we adjusted my dosage and added calcium and vitamin D supplements, things improved. I now get a DXA scan every two years. Staying informed has empowered me.”
Sam’s Story (Trans Man, 22)
“Starting testosterone at 17 helped me feel like myself, but I worried about the impact of puberty blockers on my bones. With regular scans and weight training, my bone density is now normal for my age. My healthcare team guided me every step.”
These stories underscore the importance of accessible information and compassionate, knowledgeable healthcare. Gender-affirming hormone therapy is a powerful tool for aligning physical and emotional well-being. With the right medical support, people undergoing gender modification can maintain strong, healthy bones throughout their lives.
Modern research suggests that the greatest risks arise not from GAHT itself, but from inadequate hormone levels, insufficient monitoring, and barriers to healthcare access. NOFSA encourages all individuals undergoing gender-affirming treatment to prioritise their bone health through:
- Regular medical supervision
- Consistent hormone therapy
- Healthy lifestyle choices
- Routine DXA scans when recommended
Supporting bone health is not only a medical priority — it’s an essential part of ensuring that everyone can live with confidence, mobility, and dignity throughout every stage of life.
