On average, yes. Trans women who have undergone hormone therapy retain measurable strength advantages over cisgender women, though the gap narrows significantly over time and varies by how strength is measured. The picture is more nuanced than a simple yes or no, because different physical qualities (grip strength, muscle size, explosive power, aerobic capacity) change at different rates and to different degrees during hormone therapy.
What Happens to Muscle Mass on Hormone Therapy
When trans women begin estrogen-based hormone therapy and suppress testosterone, they lose muscle. But the loss is smaller than many people expect. A systematic review in the British Journal of Sports Medicine found that lean body mass decreased by roughly 3% to 5% after 12 months of treatment. Since cisgender men typically carry about 30% to 40% more muscle mass than cisgender women, a 5% reduction closes only a fraction of that gap.
Longer treatment helps, but not dramatically. One study tracking quadriceps muscle size found a 9.5% decrease after 12 months and an 11.7% decrease after 36 months. A different study looking at the lower leg found just a 1.5% decrease at 12 months and 3.8% at 24 months. The rate of loss appears to slow over time rather than continue at a steady pace, and researchers note there simply isn’t enough long-term data to know where the decline levels off.
Grip Strength: A Direct Comparison
Grip strength is one of the most commonly used benchmarks because it’s easy to measure and closely tracks overall upper-body strength. A cross-sectional study published in BMJ Open compared trans women on hormone therapy directly with cisgender women. Trans women averaged 40.7 kg of grip strength compared to 34.2 kg for cisgender women, a difference of about 19%. That gap is statistically significant and large enough to matter in physical tasks and competitive contexts.
This finding aligns with the broader pattern identified in review papers: roughly 12 months of testosterone suppression results in only about a 5% reduction in strength measures, while the baseline male-female strength gap is far larger than 5%.
Explosive Power Tells a Different Story
Not every measure of physical performance follows the same pattern. When researchers tested vertical jump height, trans women performed almost identically to cisgender women: 34.0 cm versus 34.2 cm. Push-up performance was also similar, with trans women completing about 18 on average compared to about 20 for cisgender women. Both groups scored far below cisgender men, who averaged 47.3 cm on vertical jump and 48 push-ups.
Maximal aerobic capacity showed the same convergence. Trans women averaged 29.4 ml/kg/min, nearly identical to the 30.4 ml/kg/min recorded for cisgender women, while cisgender men averaged 41.2 ml/kg/min. This suggests that for activities demanding cardiovascular endurance and power relative to body weight, the gap between trans women and cisgender women may be small or nonexistent.
Why the Blood Changes Faster Than the Muscles
One reason aerobic capacity equalizes more quickly is hemoglobin. Testosterone drives the body to produce more red blood cells, which carry oxygen to working muscles. Higher hemoglobin levels give a measurable endurance advantage. In trans women, hemoglobin drops to cisgender female levels within just three to four months of starting hormone therapy and stays there. This is one of the fastest physiological changes, far outpacing the slow reduction in muscle tissue.
So while the oxygen-delivery system reaches parity relatively quickly, the muscles that use that oxygen retain much of their size and contractile strength for years.
Bone Structure Doesn’t Change
Some strength advantages have nothing to do with muscle at all. Going through testosterone-driven puberty produces a larger skeleton: broader shoulders, longer limbs, a narrower pelvis, and different joint angles at the elbow and knee. These structural differences create mechanical leverage advantages in throwing, jumping, hitting, and kicking. Broader shoulders allow more muscle attachment area. A narrower pelvis and smaller knee angle generate more force during extension movements like squatting or sprinting.
Hormone therapy does not reverse these skeletal changes. In fact, bone density in trans women tends to stay the same or even increase slightly during treatment. The bones established during male puberty remain intact, and whatever leverage advantages they provide persist indefinitely. This is a permanent structural difference that no amount of testosterone suppression can alter.
Why the Answer Depends on What You Measure
The research paints a split picture. For raw strength measurements like grip strength and absolute muscle mass, trans women on hormone therapy retain a meaningful advantage over cisgender women. The gap shrinks with treatment but does not close, even after several years. For performance tasks that depend more on body-weight-relative power and aerobic fitness, like vertical jump and VO2 max, trans women and cisgender women perform similarly.
This split matters because different sports and physical activities load these qualities differently. A sport that rewards absolute upper-body force, like weightlifting or wrestling, would be more affected by the retained strength advantage. A sport that rewards endurance relative to body weight, like distance running, might see less of a difference.
What Sports Organizations Have Decided
The gap between what hormone therapy changes and what it doesn’t has pushed major sports bodies toward increasingly restrictive policies. World Athletics acknowledged that trans women retain advantages in muscle mass, volume, and strength beyond 12 months of hormone therapy, even when testosterone is held below 5 nanomoles per liter. The organization concluded that the physical advantage from male puberty cannot be fully eliminated through testosterone suppression alone.
The International Olympic Committee moved away from setting specific testosterone thresholds in its 2021 framework, leaving decisions to individual sports federations. Since then, several federations have effectively barred trans women who went through male puberty from elite female competition, citing the retained physiological differences. The policy landscape remains uneven across sports and levels of competition, with recreational and lower-level leagues often applying different standards than elite governing bodies.
The Bottom Line on Strength
Trans women who have undergone hormone therapy are, on average, stronger than cisgender women in absolute terms. Grip strength remains roughly 19% higher, and lean body mass decreases only modestly with treatment. At the same time, performance measures that depend on aerobic capacity and relative power show near-complete convergence. Skeletal structure, which provides mechanical leverage for many strength tasks, does not change with hormone therapy. The strength difference is real but uneven across different physical qualities, and it narrows without disappearing over the course of treatment.