Which hormone is responsible for ejecting milk from the mammary glands?
Oxytocin
Oxytocin is a hormone that is made in the brain, in the hypothalamus, and it is transported to, and secreted by, the pituitary gland, which is located at the base of the brain. It acts both as a hormone and as a brain neurotransmitter. The release of oxytocin by the pituitary gland acts to regulate two female reproductive functions like childbirth and Breastfeeding.
The hormone prolactin is responsible for milk production.