Health Library

The Controversy Over Added Hormones in Meat and Dairy

Hormones in meat image It is common to see ads about hormone free meat or diary. Is it good information or hype? The truth is, there may not be clear answers.

Hormones and Steroids Used in Cattle

Hormones are present in all animal products. Some are natural, others may be added through supplements. Hormones and steroids are given to livestock. It can increase the amount of dairy products and beef. Some hormones that may be used in dairy cows include:

  • Recombinant bovine growth hormone (rBGH)— to increase milk (may also be called bovine somatotropin [BST])
  • Estrogen, testosterone, and progesterone—steroids to speed growth and production

Natural BGH and rBGH both increase the level of another hormone call insulin-like growth factor (IGF-1) in the cow.

Beef cattle are often given steroids to increase and speed growth. Common steroids include:

  • Natural steroids like estradiol, testosterone, and progesterone
  • Man-mad steroids from compounds

Major groups such as FDA and Food and Agricultural Organization state track level of hormones in food. They state that the levels of hormones in food are safe to eat. Not everyone agrees.

Where Concerns Lie

Hormones play an important role in the body. It is reasonable that people are concerned with hormones we are adding to our food chain. For example, IGF-1 may stimulate growth in some tumors. This may affect the risk of cancer and aggressive cancers.

Foods naturally have some hormones. It is not always clear how the use of hormones, like steroids, change these amounts in food. Our body's breaks down food in a process from the mouth through the stomach and intestines. Active forms of hormones may not survive through this process or cooking. Finally, even if active hormones make it into the body, they may not be able to play a role in the human body. Hormones from cows may not be able to interact with human cells.

Government and safety organizations tried to answer some of major questions. Their research found that:

  • Natural BGH and rBGH is not active in humans. So even if the body did absorb it from food, it shouldn't cause changes.
  • IGF-1 is slightly higher in cows treated with rBGH, than those that aren't. However, the difference was very small and similar to normal differences in IGF-1 found between cows.
  • The human body makes its own IGF-1. One study estimated a 0.09% increase in IGF-1, after drinking milk of rBGH cow. FDA also estimated that less than 1% of total IGF-1 in the body was from drinking milk from rBGH cow, even when the child drink a high amount of milk.

Many national groups have studied the effects of rBGH. Studies have found no clear links between milk from rBGH cows and health issues in humans. The hormone may cause health problems for the cows. The most common problem is an increased risk of infection in the udders. These infections are treated with antibiotics. It is unknown if the antibiotics used to treat the cows create harm in humans.


There are no studies that show a solid answer for either side. Research will continue. Some countries have banned hormone. This is most often because of harm that it may do to the animals, not humans. Talk to your doctor about healthy choices for you.

Many stores and buyers will not use dairy or beef from farms using hormones. This is good news if you choose to avoid these products. Look for:

  • Certified organic meat and meat products—Organic animals cannot be given antibiotics or growth hormones. It is also safe to buy imported European meat. Added growth hormones are banned in Europe.
  • rBGH-free or certified organic milk and dairy products—Organic dairy farms do not allow the use of rBGH. Some products may not be organic but still avoid rBGH. Look for information on the label. It is also safe to buy imported European and Canadian cheeses and other dairy products. rBGH is banned in these countries.


The Organic Farming Research Foundation

US Food and Drug Administration

Canadian Resources

Dietitians of Canada

Health Canada


Andersson AM, Skakkeback, NE. Exposure to exogenous estrogens in food: possible impact on human development and health. EurJ Endocrinol. 1999;140(6):477-485. Accessed June 8, 2020.

Bovine somatotropin (BST). US Food and Drug Administration website. Available at: Updated April 21, 2020. Accessed June 8, 2020.

Health concerns about dairy products. Physicians Committee for Responsible Medicine website. Available at: Accessed June 8, 2020.

Recombinant bovine growth hormone. American Cancer Society website. Available at: Accessed June 8, 2020.

Vitale DC, Piazza C, Melilli B. Isoflavones: estrogenic activity, biological effect and bioavailability. Eur J Drug Metab Pharmacokinet. 2012;28(1):15-25.