It is known as "liquid gold", but for people buying and selling breast milk online, it may be more like fool's gold, a 7NEWS investigation found.
"I'm a mother of two," said Kayla Infante, a Greeley stay-at-home mother who is breastfeeding her 6-month-old daughter. "I'm what they call an 'overproducer.' In the beginning, I had enough for a small village."
Infante had a freezer full of liquid gold when she heard about a website called "Only The Breast," a classified ads site for human milk, listing samples for $1 to $5 an ounce.
"We had 150 ounces just stocked up, and so it just made sense to try to do that," said Infante.
With so many advocates promoting the benefits of breastfeeding for babies, the online milk market has become a high-stakes game for buyers and sellers, like Infante.
"I figured there would be maybe a few weird inquiries, but um... I didn't expect to get what I got," she said.
We'll get back to what she got it, but first we get gowned and gloved to go behind the scenes.
The traditional way mothers get breast milk for their babies if they cannot provide it is to come to a milk bank, where all the milk is donated.
Mothers' Milk Bank in Arvada is the largest milk bank in North America, its lab processes about 3,000-4,000 ounces of donor milk a day, mostly for neonatal care units and premature infants.
"All of our donors are tested for the same things that blood donors are tested for -- HIV, the Hepatitis, etc.," said Laraine Lockhart Borman with Mothers' Milk Bank.
Not only does the bank screen donors, the milk goes through a long process of pasteurization and testing for bacteria.
"We have 30-plus years of providing milk in a non-profit environment where moms are not compensated. We feel there would be certain risks associated with that," said Lockhart Borman.
But are those risks real? Or are milk banks protecting their market?
Their processing fee is $4 an ounce.
Researchers at Nationwide Children's Hospital in Columbus, Ohio wanted to find out.
"We purchased milk, just as if we were a mom," said Sarah Keim, PhD, a researcher with Nationwide Children's Hospital.
Keim bought more than 100 online milk samples and had them tested.
What she found was chilling.
"We found that actually about three-quarters of the samples that we purchased had either high levels of bacteria or had detectable amounts of bacteria that are known to cause disease," said Keim.
The samples were not just high in harmful bacteria (breast milk normally has some amount of bacteria, but not Salmonella and other dangerous types), 10% of the supposed breast-milk samples tested positive for high levels of cow's milk, a sign sellers topped off samples to make more money.
"I think it's pretty clear from the series of studies that we've conducted that it is not safe to buy breast milk on the internet and feed it to your infant," said Keim.
And it is not just buyer beware, sellers like Infante have stories, too.
"The man said that his wife died giving birthday and he needed milk for his twins," said Infante, who soon realized the people trying to buy her breast milk had a complicated scheme for payment. "You can send the shipping fees to the shipping agent... It was a scam."
Others wanted Infante to nurse them.
"It's degrading and it feels horrible," said Infante. "This just goes to show people will take advantage of anything."
She has since pulled her ad and is now planning to donate to a milk bank, instead.
"I guess I would say for buyers and sellers to be equally cautious," she said.
Only The Breast did not respond to our requests for comment.
The website does instruct people to pasteurize milk before giving it to babies, but Keim said that process can be difficult to do correctly, and it doesn't guarantee cow's milk will not be added.
The U.S. Food and Drug Administration does not regulate the sale of human breast milk, although a few states do. Colorado is not one of those states.