While the World Athletics rules advocate that testosterone is a direct determinant of muscle performance, our research indicates this relationship is not so simple.
Transgender youth have a number of research-backed medical options available to them. The multidisciplinary approach ranges from promoting family support to hormone treatments to surgery.
A growing online movement believes that giving up masturbation can make us happier and boost our testosterone levels.
New legislative proposals want to allow 'sex testing' of girl athletes through genital exams and genetic and hormone testing.
Claims that a product can boost testosterone levels imply that this will lead to a gain in muscle and strength.
Why does COVID-19 hit men harder than women? Is the disparity in mortality rates due to male hormones or an underlying difference in the male versus female immune system?
The science is not so clear cut.
The link between testosterone and empathy is complicated. We don't have all the answers yet.
A new study of nearly 500,000 individuals finds that many genes affect same-sex behavior, including newly identified candidates that may regulate smell and sex hormones.
Athlete Caster Semenya will need to take hormone-lowering agents, or have surgery, if she wishes to continue her career in her chosen events. But the decision to ban her is flawed on many grounds.
Sports are segregated by sex. But what happens when athletes don't fit neatly into sport's definition of gender?
The great South African runner Caster Semenya may have competed in her last 800-metre race. She has been demonized for more than a decade, like many other female athletes before her.
Sport is a special domain, but it is not immune from the law and human rights. We're yet to see if the United Nations Human Rights Council will take steps following a new ruling on testosterone.
The question of whether heightened testosterone confers an advantage for some female athletes remains contentious.
So-called normal levels of testosterone are approximations, but can help researchers investigate disease and treatments.
What we thought we knew about male development since the 1950s has now been turned on its head.
Disorders affecting penis development are among the most common birth defects seen in humans, and rates are on the rise.
Gender differences in jobs and attitudes are wider in countries with more equality, but that's not the end of the story.
Better childhood environments linked with higher testosterone levels in later life.
A new policy may spell the end of Caster Semenya's illustrious running career.