Castration before puberty leads to low interest or failure to develop. Castration after puberty or especially after sexual behavior has been established does not always lead to the stopping of sexual behavior. There is an effect but it is not as severe as with other animals, and it can vary from one individual to another. We can manipulate testosterone levels in men and observe an increased frequency of erection and sexual activity. There are so many other factors, however, that hormonal effects are not always reliably correlated with sexual behavior.
Female hormone is estrogen.
This is the only time we see sexual behavior in many species but there are exceptions in primates and other animals. If we remove ovaries or stop estrogen production using drugs, sexual behavior in rats and other lower animals stop. We also see sex behavior come back when we reintroduce estrogen. Sex drive is not reliably dependent on estrogen levels for women. Testosterone levels, however, does correlate with sexual behavior in women.