What this claim means

For dairy cows, the FDA allows the injection of a genetically engineered growth hormone to increase milk production. The drug is known as recombinant bovine somatotropin (rbST) and recombinant bovine growth hormone (rbGH) (both versions can be seen on labels of dairy products). Dairy cows that are treated with this artificial growth hormone are generally injected every two weeks for eight months out of the year.

The Food and Drug Administration (FDA) approved the drug in 1993, when it was petitioned for use in dairy production by the biotechnology company Monsanto Corporation. After its 1993 approval, it was first sold commercially in the U.S. in 1994. Its use is banned in many countries, including Canada, Japan, Israel, and the member states of the European Union.

The Food and Drug Administration (FDA) oversees labeling of dairy products. By law, labels must be truthful and not misleading, and FDA can issue guidance to the industry on how to ensure that labels are truthful and not misleading. The FDA issued guidance in 1994 on labeling of dairy from cows not treated with rbST, and wrote that a statement that asserts that rbST has not been used in the production of the milk has the potential to be misunderstood by consumers. The FDA suggested the claim may be misleading unless accompanied with a statement such as “no significant difference has been shown between milk derived from rbST-treated and non-rbST treated cows.”

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Why it matters

Animal welfare. Injections of rbST can impact cow health, most notably an increase in the risk of clinical mastitis and lameness. This risk is noted on the label of Posilac, as required by the Food and Drug Administration.An expert panel established by the Canadian Veterinary Medical Association (CVMA) found the increased risk of clinical mastitis to be approximately 25 percent. Mastitis is a bacterial infection of the mammary glands (udder). The CVMA panel estimated a 55 percent increase in the risk of developing clinical signs of lameness in cows treated with rbST. There is also an increased risk of twinning.

Antibiotic use in animal agriculture. Clinical mastitis, which is more likely to occur when cows are injected with rbST, can and should be treated with antibiotics. It is an example of how poor farming practices that neglect animal welfare and artificially increase production beyond the animal’s natural capabilities can lead to the increased use of antibiotics.

Human health.  It is not clear whether rbST poses a risk to human health; however, Consumers Union, the advocacy arm of Consumer Reports, has raised concerns about the FDA’s approval process. Prior to its approval of the rbST drug in 1993, the Food and Drug Administration (FDA) did not require a human safety toxicological assessment usually required for a veterinary drug. This conclusion was based largely on a study by Monsanto that, according to the FDA, showed “no toxicologically significant changes” in rats. The study was never published. When the full study was later made public, it revealed there were indeed toxicologically significant changes in the treated rats that should have triggered a full human health review.

Is the claim verified? 


No. The Food and Drug Administration (FDA) does not verify labeling claims and does not require other third-party verification of this claim.

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What additional information tells you the claim has been verified?

It is important to look for milk and dairy products from cows that were not treated with genetically engineered growth hormones. On its own, a “no rbST” or “no rbGH” labeling claim is not required to be third-party verified. Consumers should look for the following additional labels that offer assurance that the claim was verified:

USDA Organic
Certified Humane Raised and Handled
Animal Welfare Approved
American Humane Certified
American Grassfed