Selling human breast milk online has become a burgeoning business, but doctors say the "supposed health benefits" of this craze are "bunk," CBS News reported.

Although many websites and forums claim their human milk products are "clean" and more digestible than cow's, researchers led by Dr. Sarah Steele of the Global Health and Policy Unit at Queen Mary University of London found that these purported benefits do not stand up clinically. In fact, investigators claim raw human milk purchased online or in an unpasteurized state poses many serious health risks.

"Online forums are replete with posts boasting about the immune, recovery, nutritional and muscle building benefits of human milk ... Such purported benefits do not stand up clinically, however," researchers write in the study, according to Mashable.

Steele and her colleagues said human milk can be very hazardous if used to replace a balanced diet.

"Nutritionally there is less protein in breast milk than other milks like cow's milk," Steele said in a statement. "Potential buyers should be made aware that no scientific study evidences that direct adult consumption of human milk for medicinal properties offers anything more than a placebo effect."

They also note that the failure of women to sanitize properly when expressing milk, the failure to sterilize equipment properly, and the improper or prolonged storage and transportation of milk can expose consumers to bacterial food-borne illnesses like any other raw milk.

The lack of pasteurization and testing not only indicates a bacterial risk but also exposes consumers to a host of infectious diseases, including hepatitis, HIV and syphilis.

"While many online mums claim they have been tested for viruses during pregnancy, many do not realize that serological screening needs to be undertaken regularly," Steele said. "Sexual and other activities in the postpartum period may expose the woman expressing to viruses that they may unwittingly pass on to consumers of the milk."

Researchers call for health professionals and regulators to issue public guidance against the purchasing of human milk from Internet sources for adult as well as infant feeding.

The findings are detailed in the Journal of Royal Society of Medicine.