Bovine Growth Hormone (rBGH)

library / Bovine Growth Hormone (rBGH)

Bovine growth hormone (BGH), or Bovine somatotropin (abbreviated bST and BST) is a protein hormone produced in the pituitary glands of cattle.

BST can be produced synthetically, using recombinant DNA technology. The resulting product is called recombinant bovine somatotropin (rBST), recombinant bovine growth hormone (rBGH), or artificial growth hormone. It is administered to the cow by injection and used to increase milk production.

In 1937, the administration of BST was shown to increase the milk yield in lactating cows by preventing mammary cell death in dairy cattle. It was found to prevent milk production from decreasing over the 300 days period of a cow's normal lactation.

The sale of Posilac is illegal in virtually every developed country with the exception of the United States.In the United States, the use of rbST has been approved by the FDA.

Health concerns continue to mount on the use of hormones in the food supply. Injecting rBGH into cows increases the levels of IGF-1 in the cows' milk, which has been linked to abnormal cell growth and cancer in recent studies. 


Meal Genius does not endorse the use of hormones. We advise you to choose organic milk from grass-fed cows which is free of synthetic hormones.


Crooker, BA; et al. (1994). Dairy Research and Bovine Somatotropin. University of Minnesota. Retrieved on 2008-01-16.