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.
Until now, Australia was the only country that required youth with gender dysphoria to seek approval from the Family Court for the second stage of hormone treatments.
Some parents think their four-year-old boy's emotional outbursts and aggressive behaviour can be blamed on their hormones. Here's why that's a myth.
Athletic ability is often linked to size – of muscles and bones. New studies are suggesting, however, that the relative size of two fingers could be more predictive of ability.
Having a newborn can be rough, whether you're a mom or a dad. New research ties men's testosterone to their postpartum depression – with some surprising upsides for their partners.
Here's what research actually says about differences between males and females – and the question of what's innate and what's acquired.
Tumour evolution was first identified 40 years ago. We're finally making good progress with it.
Doctors should examine more than just sperm count in infertile men.
Women are paid 20 percent less than men in the US but live about five years longer than men. You might be surprised at the reasons that men, on average, die at a younger age.
Morning penile erections affect all males, even males in the womb and male children.
Having a bit of a tummy might not be the end of the world for men after all.
A 1992 paper predicted that if women's running performance continued to improve as rapidly as it had since the 1920s, top women athletes would soon be running as quickly as the men.
Some women naturally produce high levels of testosterone. Why is this innate condition treated differently from other conditions that potentially enhance athletic performance?
Until recently, women with higher-than-expected testosterone levels were declared ineligible to take part in track and field athletics.
While many men want to seek treatment for 'low T,' a low level of testosterone is good when it comes to being a nurturing father. Here's why.