A study conducted by a team led by Nationwide Children’s Hospital in Columbus, Ohio found that ten percent of the breast milk samples purchased from Internet milk-sharing websites contained added cow’s milk. The study, which was published in the journal Pediatrics, drew its conclusion from the testing of 102 samples of breast milk purchased from multiple milk-sharing websites. Eleven of the 102 samples contained bovine mitochondrial DNA, in addition to human DNA. This finding spurs concerns regarding the safety of breast milk sold online, as cow’s milk is not recommended for children below the age of 12 months. Additionally, the recipient child of the contaminated breast milk could potential have an allergy or intolerance to cow’s milk.

There is very little regulatory oversight of the breast milk industry. FDA does not oversee the industry, and simply cautions parents on the many potential risks of feeding a baby human milk from a source other than the baby’s mother. FDA specifically recommends against feeding infants “breast milk acquired directly from individuals or through the internet,” because the donor is “unlikely to have been adequately screened for infectious disease or contamination risk.” FDA states that the potential risks of feeding human milk from a source other than the baby’s mother include exposure to infectious diseases, including HIV; chemical contaminants, such as some illegal drugs; and prescription drugs that may be found in human milk.

FDA directs consumers to contact their state’s department of health to find out if it has information on local human milk banks, or to utilize resources provided by the Human Milk Banking Association of North America (HMBANA), a “voluntary professional association for human milk banks,” which implements voluntary safety guidelines for screening donors for member banks.

Dilution is not the only risk involved in purchasing online breast milk – a 2013 study conducted by the same organization found that almost 90% of delivered human breast milk arrived warmer than the recommended storage temperature. Likely due in part to this temperature discrepancy, 75% of the same samples were found to contain illness-causing bacteria. The study of potential risks of breast milk purchased online has not been exhausted, and Nationwide Children’s Hospital is currently testing breast milk purchased online for the presence of caffeine or nicotine.