Why do i have white nipple discharge?

Uncertain.: Possible causes for galactorrhea include but are not limited to use of birth control pills, tricyclic antidepressants, antipsychotic meds, some sedatives, fennel, anise, fenugreek, some hypertension meds, cocaine, opioids, hypothyroidism, prolactinoma, renal dz, testosterone deficiency in men ; significant breast stimulation.

Possibly normal: The breast/nipple can have discharge/drainage of many different colors. White discharge is likely a benign discharge, but see your doctor to have it checked out.