The specific effect time after milk return injection varies from person to person, in general, the effect can be seen in 2-3 days, a few women may need about 1 week to see the effect. Breast milk is produced by the pituitary gland through the secretion of prolactin, which stimulates the secretion of milk, while the principle of action of the milk return injection is to inhibit the production of prolactin to achieve the effect of milk return. How long does it take for the injections to take effect depends on the individual’s condition and sensitivity to the drug. For women who are more sensitive, the effect can be seen within a short period of time after the injection, and most women will experience the effect 2-3 days after the injection. It is recommended to choose loose clothing and bra, follow the doctor’s instructions and arrange the medication, at the same time, you should eat a light diet and do not squeeze your breasts.