Breast milk is in demand - and not just by moms buying it for their babies.
Some body builders drink it to bulk up and a spa in Chicago, Mud Facial Bar, is even giving "breast milk facials." The owner says the breast milk is carefully screened and helps acne, eczema and other skin problems.
But how safe is breast milk that's sold over the internet?
While perfectly legal, an INSIDE EDITION investigation found that some samples sold online contain bacteria that could be potentially harmful to a child.
INSIDE EDITION purchased milk from eight different mothers across the country and sent the samples to a lab for testing by breast milk expert Dr. David Newburg. The results were startling.
"Seven of the eight samples acquired over the internet I would not feed to infants," Dr. Newburg said.
He said that a staggering 87 percent of the samples contained potentially dangerous bacteria. Four of the samples were loaded with gram negative bacteria, which can cause infections.
"These bacteria that we found could very well make infants sick," he said.
One woman sold INSIDE EDITION milk on the street in New York City and while the exchange was legal, the lab found the level of bacteria in the sample was just too high to calculate.
When INSIDE EDITION’s Lisa Guerrero identified herself to the woman and asked the seller about the milk, she did not stick around.
With high demand for the milk, mothers say it can be a personal gold mine.
"We’ve made a pretty penny," one mom, Allison, told INSIDE EDITION. She’s been able to buy a new living room set and a dining room table with the cash.
"We’ve been able to put away for our children’s college education," she added.
Her friend Kaitlyn, a mom of four, said she has made "a few thousand" from selling her own milk – although it isn’t always for babies.
"Seeing a man drink my milk was quite creepy," she said.
Kaitlyn and Allison are both nurses and say they’re careful about being sanitary when they pump and prepare their milk for sale. Their friend Missy, to whom they donate their milk, said she knows the women are safe.
"I know Allison and Kaitlyn," she said. "I know where the milk is coming from and that it's clean."
In order to ensure mothers are receiving safe breast milk for their babies, the FDA recommends going to a milk bank where the milk is pasteurized to get rid of potentially harmful bacteria.
"You have to be educated and know what you are doing to make sure the milk you are supplying is healthy and safe," Allison said.