No hormones are added to your milk.

Twice this weekend I was asked the same question – are there added hormones in milk?

I’m happy I could give the answer – no!  There are no added hormones in milk.  Not in conventional milk nor in organic milk.

First of all, in Michigan, farmers don't give their cows hormones to help them produce more milk. (We never have on this farm, either.)  When farmers did it in the past, there was no way to tell the synthetic hormone from the natural hormone, because cows already produced it.  (So there was no test for it.)  But when consumers didn't want it, farmers stopped using it.  In Michigan, that happened in 2008.  The rest of the country has done the same.

All milk - organic and conventional - has natural hormones, because it is coming from a lactating mammal.  But!  Never fear because ...

Humans do not have receptors for bovine hormones.

It's not me saying it - it's scientists.

Dr. Terry Etherton: “There are zillions of protein hormones in both plant and animal foods. They are digested in the stomach, which kills their ability to have any biological activity." Best Food Facts

Another way to put it, from Science Blogs: Aetiology by Tara C. Smith, is:

“Studies have shown that human and bovine milk normally contain small amounts of growth hormone. After ingestion, growth hormone as any other protein in milk: it is digested into its constituent amino acids and di- and tripeptides. There is no data to suggest that BST present in milk can survive digestion or produce unique peptide fragments that might have biological effects.

Even if BST is absorbed intact, the growth hormone receptors in the human do not recognize cow BST and, therefore, BST cannot produce effects in humans. … Overall studies show recombinant growth hormone cannot be absorbed intact through intestine and even if small amounts get absorbed, there is no receptor for bovine growth hormones in humans.”

Or from the American Cancer Society:

"Neither natural nor synthetic BGH has been found to affect human growth hormone receptors."

Let me also add that these are naturally-occurring hormones, which all milk has, because it comes from lactating animals.  Hormones aren't just present in milk - they're present in all types of food. For instance, look at this chart about estrogen from Allen Young, Utah State University Extension dairy specialist and associate professor:

                                               
So there’s your milk news for the day.  Please feel free to ask any questions you have!

Other questions answered:

What's the difference between whole, 2% and skim milk?

How long can you drink milk past the sell-by date?

Does milk make girls develop faster?  No.

What's the difference between organic and conventional milk?  Process, not product.

Why does organic milk have a longer expiration date?  It's heated up hotter.

and...

There are no antibiotics in your milk.

This is what we do to guard against human error to never have antibiotics in milk.

GMOs, no antibiotics, etc.