Final answer:
The hormone that allows men to build more muscle mass than women is testosterone. Testosterone, which is in higher quantities in men, is critical for muscle development and overall muscle mass accrual. It is also the reason why anabolic steroids, synthetic forms of testosterone, are banned in sports.
Step-by-step explanation:
The essential hormone that men have in higher amounts than women, which allows men to build more muscle mass than women, is testosterone. Testosterone is the main sex hormone in males and plays a critical role in muscle development among many other biological processes. It's because of higher levels of testosterone that men generally have greater muscle mass than women. Testosterone is a steroid hormone that helps increase muscle mass by promoting the growth of muscle fibers and stimulating protein synthesis within the body.
While females also produce testosterone, their levels are significantly lower compared to males. In contrast, females have higher levels of estrogen, which is the dominant sex hormone in women. This hormonal difference is a key factor in why men and women have differing capabilities for building muscle mass naturally. The use of synthetic hormones to enhance muscle performance, such as anabolic steroids which mimic the effects of testosterone, is banned in many sports due to health risks and the potential for unfair advantage.