A Gold Coast mum is trying to sell her breast milk on Craigslist.

A “good-looking” Gold Coast woman with “big boobs” has had worldwide publicity after offering her breast milk for sale on Craigslist.

The woman, from Southport, called for expressions of interest in a post, which appeared last Friday.

“Just seeing if there is any interest in buying breast milk? I have an oversupply. And I’ve donated heaps,” the post read.

“I know bodybuilders are supposed to go nuts for it because of how quickly you can bulk on it. Anything else you want to do with it is totally up to you. There are no other services offered! And sorry but no, you can’t get it direct from the source!”

The woman said she was selling the milk in 250ml bags and was thinking of charging $20 per bag.

"And if it's of any interest, I am good-looking, late 20s, big boobs (at the moment anyway)."

The Craiglist post even made the news in UK media. But there are a few flaws in the Gold Coast woman's plan.

Firstly, it's illegal to sell human body parts in Australia. Secondly, it's doubtful breast milk really can do much for bodybuilders.

Sports dietitian Brian St Pierre tells Men's Health that no one knows whether breast milk helps build more muscle.

"All you’re going on is very rare anecdotes from online forums (note: a terrible source)," he explains.

Is this body due to breastmilk? Probably not. Photo via iStock.

"Is it possible? Of course. Is it likely? No. Are there easier and cheaper ways to get nutrients that help you put on muscle? Absolutely. This stuff probably just isn’t special, and it’s not worth the hassle, risk, or money.”

There is a health risk. A study published in the journal Pediatrics found 63 per cent of samples of breast milk purchased online tested positive for staphylococcus, with a further 36 percent testing positive for streptococcus, and three percent for salmonella.

But leftover breast milk can be put to good use if donated to organisations like Mothers' Milk Bank, based in Banora Point, NSW.

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Milk donated by mums through the bank helped more than 300 babies last year. All the milk is screened and pasteurised.

Spokesperson Marea Ryan says demand is "huge".

"We could feed a lot more babies, easily, if we had more milk and we could be funded," she tells Mamamia. "We operate on volunteers and by donations only."

Donated breast milk is given to babies. Photo via iStock.

Ryan says the bank doesn't give breast milk to adults, but she says there's a demand for it - not so much from bodybuilders as from cancer patients. Some believe it has cancer-fighting properties, and also helps boost the immune system during treatment.

"There are quite a number of adults who have cancer who do access milk, through the websites that are out there that share milk," she adds.