Beef (and Residual Hormones?). It’s What’s for Dinner.

Kira Le, MJLST Staffer

The beef industry in the United States has been using hormones, both natural and synthetic, to increase the size of cattle prior to slaughter for more than a century.[1] Capsules are implanted under the skin behind a cow’s ear and release specific doses of hormones over a period of time with the goal of increasing the animal’s size more quickly. Because the use of these hormones in the beef industry involves both drug regulation and food safety regulations, both the U.S. Food and Drug Administration (FDA) and the United States Department of Agriculture (USDA) are responsible for ensuring the safety of the practice and regulating its use.[2] According to the FDA, “scientific data” is used to establish “acceptable” safe limits for hormones in meat by the time it is consumed.[3] Agricultural science experts support the fact that the naturally-occurring hormones used in beef production, such as estrogen, are used in amounts much smaller than those that can be found in other common foods, such as eggs and tofu.[4] However, the debate within the scientific community, and between jurisdictions that allow the sale of hormone-treated beef (such as the United States) and those that have banned its importation (such as the European Union), is still raging on in 2022 and has led to significant distrust in the beef industry by consumers.[5] With the release of research earlier this year presenting opposing conclusions regarding the safety of the use of synthetic hormones in the beef industry, the FDA has a responsibility to acknowledge evidence suggesting that such practices may be harmful to human health.

Some defend the use of hormones in the beef industry as perfectly safe and, at this point, necessary to sustainably feed a planet on which the demand for meat continues to increase with a growing population. Others, such as the European Union and China, both of which have restricted the importation of beef from cattle implanted with growth-promoting hormones, argue that the practice threatens human health.[6] For example, a report out of Food Research Collaboration found that a routinely-used hormone in United States beef production posed a significant risk of cancer.[7] Such a finding is reminiscent of when, in the not-too-distant past, known carcinogen diethylstilbestrol (DES) was used in U.S. cattle production and led to dangerous meat being stocked on grocery store shelves.[8]

This year, research published in the Journal of Applied Animal Research discussed the effects that residual hormones left in beef and the environment have on human health in the United States.[9] Approximately 63% of beef cattle in the United States are implanted with hormones, most of which are synthetic.[10] Despite organizations and agencies such as the FDA assuring consumers that the use of these synthetic hormones in cattle production is safe, the residues that can be left behind may be carcinogenic and/or lead to reproductive or developmental issues in humans.[11] Furthermore, the National Residue Program (NRP), housed in the USDA, is not only the “only federal effort that routinely examines food animal products for drug residues,” but also only examines tissues not commonly consumed, such as the liver and kidney.[12] Researchers Quaid and Abdoun offer the example of Zeranol, a genotoxic synthetic hormone used in beef production in the United States that activates estrogen receptors, causing dependent cell proliferation in the mammary glands that may result in breast cancer.[13] They also noted the problem of residual hormones found in the environment surrounding cattle production locations, which have been found to reduce human male reproductive health and increase the risk of some endocrine cancers.[14]

Also this year, researchers published an article in the Journal of Animal Science claiming that despite the “growing concern” of the effects of residual hormones on human health, including the earlier onset of puberty in girls and an increase in estrogen-related diseases attributed to the excessive consumption of beef, research shows that cattle treated with hormones, “when given at proper administration levels, do not lead to toxic or harmful levels of hormonal residues in their tissues.”[15] The researchers concluded that the hormones have no effect on human health and are not the cause of disease.[16]

Perhaps it is time for the FDA to acknowledge and address the scientific disagreements on the safety of the use of hormones – synthetic hormones, especially – in beef production, as well as reassure consumers that players in the agriculture industry are abiding by safety regulations. Better yet, considering the currentness of the research, the inconsistency of the conclusions, and the seriousness of the issue, formal hearings – held by either the FDA or Congress – may be necessary to rebuild the trust of consumers in the U.S. beef industry.


[1] Synthetic Hormone Use in Beef and the U.S. Regulatory Dilemma, DES Daughter (Nov. 20, 2016), https://diethylstilbestrol.co.uk/synthetic-hormone-use-in-beef-and-the-us-regulatory-dilemma/.

[2] Id.

[3] Steroid Hormone Implants Used for Growth in Food-Producing Animals, U.S. Food and Drug Admin (Apr. 13, 2022), https://www.fda.gov/animal-veterinary/product-safety-information/steroid-hormone-implants-used-growth-food-producing-animals.

[4] Amanda Blair, Hormones in Beef: Myths vs. Facts, S.D. State Univ. Extension (July 13, 2022), https://extension.sdstate.edu/hormones-beef-myths-vs-facts.

[5] See Julia Calderone, Here’s Why Farmers Inject Hormones Into Beef But Never Into Poultry, Insider (Mar. 31, 2016), https://www.businessinsider.com/no-hormones-chicken-poultry-usda-fda-2016-3 (discussing the debate within the scientific community over whether the use of hormones in animals raised for human consumption is a risk to human health).

[6] New Generation of Livestock Drugs Linked to Cancer, Rafter W. Ranch (June 8, 2022), https://rafterwranch.net/livestock-drugs-linked-to-cancer/.

[7] Id.

[8] Synthetic Hormone Use in Beef and the U.S. Regulatory Dilemma, DES Daughter (Nov. 20, 2016), https://diethylstilbestrol.co.uk/synthetic-hormone-use-in-beef-and-the-us-regulatory-dilemma/.

[9] Mohammed M. Quaid & Khalid A. Abdoun, Safety and Concerns of Hormonal Application in Farm Animal Production: A Review, 50 J. of Applied Animal Rsch. 426 (2022).

[10] Id. at 428.

[11] Id. at 429–30.

[12] Id. at 430.

[13] Id. at 432–33.

[14] Id. at 435.

[15] Holly C. Evans et al., Harnessing the Value of Reproductive Hormones in Cattle Production with Considerations to Animal Welfare and Human Health, 100 J. of Animal Sci. 1, 9 (2022).

[16] Id.