According to Han Bing, who works with the Beijing-based Hope Institute of Chinese Medicine, hashima is rarely used in clinical treatment, partly because it's so hard to source. As a result, it's also considered a luxury product reserved for the rich.

Raising frogs

At the Jurong Frog Farm, thousands of American bullfrogs cluster in shallow water in concrete pens. They're sorted not by age but by size. As soon as they reach one kilogram they're transferred to a fridge so they start to hibernate before they are slaughtered.

The meat is then packaged and shipped to local restaurants and supermarkets. At the same time, the hashima is extracted and either dried or processed to be sold as bottled "Premium Hashima with American Ginseng."

American bullfrogs are favored because of their size and the texture of the meat. However in Singapore's hot and humid climate they're difficult to breed. At the farm, the mortality rate is 80% at every stage of their life cycle, from egg to tadpole to adult frog.

"It takes a very long time, about seven to eight months from the egg to go to the adult stage. Because it's a very long life cycle we need to import to be able to supply (the market)," says Jackson Wan, a member of the Jurong team.

Frog consumption

Asia has a huge appetite for frogs. Singapore alone is thought to chew through at least five million kilograms of frog flesh each year.

That equates to around 15 million frogs each year, according to David Bickford, assistant professor at Bickford Lab, at the Environmental Science Group at the National University of Singapore, who's an expert on frog populations and threats.

The figure is based on the most recent data, from 2009, on international trade from the United Nations. By now, the figure is likely to far higher, Bickford says. And even then it doesn't include local trade.

"Across the world that number is gargantuan. I think I was quoted back when the paper first came out in 2009 saying there could easily be over one billion frogs a year that people are eating and I wouldn't back away from that. That's a pretty solid number."

Seeking health through hashima

In the context of Traditional Chinese Medicine, the promotion of hashima as a byproduct of breeding American bullfrogs for their meat is relatively new.

"Because it has collagen protein it's very good for the skin and beauty. It's especially good for women," Jackson Wan says, offering me a glass of Royal Hashima Dessert.

It's cold and reasonably refreshing, but it's hard to distinguish which of the soft chunks are frog parts and which are boiled fruit.

According to the farm, hashima contains 18 kinds of amino acids, and improves the immune system, blood circulation and skin complexion. It "balances the amount of cholesterol and minimizes heart attack and high blood pressure" and also works to "nourish and strengthen kidneys and lungs."

However, it's not advised for children. "We don't recommend they drink hashima because of the high level of hormones which may affect puberty," Jackson says.

While Bickford is skeptical of the health benefits of hashima -- "the placebo effect is incredibly strong" -- he agrees that he wouldn't recommend it for children.

"If I had a pre-pubescent son I wouldn't have him eat that dessert all the time. If male vertebrates have a lot of ingested estrogen, either direct or indirect, it's probably not good for their sexual development and the health of their endocrine system."

From his perspective, breeding a non-native species is fraught with other risks, including the spread of disease to local populations.

The frog farm says it's working to educate the public about the life cycle and benefits of frogs. Tour groups are invited to feed them, and buy a whole range of meals made from frog products, which is said to be high in protein with a similar taste and texture to chicken.

On its own, hashima is tasteless, which is why fruit and sugar are added to the Royal Hashima Dessert to make it sweet.

Just don't drink too much.