"Most milk is sourced from lactating dairy cows, who have high levels of circulating progesterone, insulin-like growth factor and other hormones that human bodies convert into dihydrotestosterone (DHT). These hormones can send oil glands into overdrive, which can trigger acne in susceptible people," says Tsippora Shainhouse, MD, FAAD, a board-certified dermatologist.
"While some organic milk doesn't contain added bovine growth hormones, it still contains the innate ones," Shainhouse adds. "If you believe that dairy is triggering your acne, try weaning off dairy for a month or two by switching to almond or rice milk.
If you do so, make sure you pay attention to your calcium and vitamin D intake, since "dairy is an important and often sole source" of those nutrients.