What happens to a man after castration?

No more testosterone. Castration is the elimination or blockade of androgens, such as testosterone. This is done by surgical removal of the testicles or by medications. The effects are: hot flashes, weight gain, mood changes, fatigue, loss of muscle mass, breast development, cognitive changes, impotence, loss of libido, osteoporosis, and changes in lipid profile, increased fat, and higher risk of heart attack.