Milk contains rich amount of progesterone, phytoestrogens, and fat. These elements help to make your breasts get bigger. Phytoestrogen mimics the action of estrogen and helps to grow your breast. Milk also contains some other hormones that are responsible for breast growth such as progesterone and prolactin. 5 rows · 2. Progesterone: Progesterone is known as a steroid hormone present in the human body that is.