What hormone primarily contributes to muscle growth in women?

The hormone that primarily contributes to muscle growth in women is testosterone. Although traditionally associated with male physiology, women also produce testosterone, albeit in smaller amounts. This hormone plays a crucial role in promoting muscle protein synthesis, enhancing muscle mass, and facilitating recovery after exercise.

Testosterone's anabolic effects help in building lean body mass, increasing strength, and improving overall physical performance. While estrogen also plays a role in muscle maintenance and regeneration, and insulin regulates glucose and fat metabolism, testosterone is specifically linked to the increase in muscle size and strength.

Cortisol, on the other hand, is a catabolic hormone that can lead to muscle breakdown if present in high levels for extended periods, especially due to stress. Therefore, among the given options, testosterone is the most significant for muscle growth in women.