At what week of gestation does testosterone start to be released in embryos?

Testosterone begins to be released in male embryos around the 6th week of gestation. This is a crucial time in sexual differentiation, as the presence of testosterone, produced by the Leydig cells in the developing testes, triggers the development of male secondary sexual characteristics and helps shape the male reproductive system. Prior to this, the embryo begins as a sexually indifferent structure, but the introduction of testosterone at this stage initiates the process of masculinization. Understanding the timing of testosterone production is important in the context of human development, as it plays a significant role in determining sexual characteristics.