Does cow's milk contain estrogen or other hormones?

There are a range of naturally occurring hormones found in cows’ milk, but it is generally considered that their levels are too low to exert any biological effects on consumers.

Last updated 30/04/2021

Hormones such as, estrogen, progesterone, prostaglandin and cortisone are found in low concentrations in milk. These hormones are naturally produced by the cow. When you drink milk, these hormones are digested by enzymes in the gut and as a result, are broken down and not absorbed in their active form.

Cow's milk estrogen levels could be raised if the cows were treated with artificial estrogen hormones, but the Australian dairy industry banned the use of estrogen drugs in milking cows in 2008. This was in response to the European Union (EU) prohibiting the importation of any dairy products from cows treated with estrogen hormones. Synthetic Bovine somatotropin (BST) is sometimes given to cows by American dairy farmers to boost milk production but these are strictly prohibited in the production of milk in Australia.

Was this useful?

Thank you for your feedback