http://www.reddit.com/tbIvirbw

It is speculated to be 6 times more potent than morphine.
However the article states: "This is the first natural substance to be found in humans that exploits this mechanism to relieve pain. But it's unlikely that opiorphin ordinarily has a painkilling role in the body, says Alistair Corbett, a specialist on opioids at Glasgow Caledonian University, UK. The substance could play a general role in protecting chemicals in the body from being broken down, he says."

So after a cursory search in google I stumbled upon this:
http://m.pnas.org/content/103/47/17979.full

Which states that "Zinc metal ectopeptidases controls the receptor-dependent activity of neural and hormonal mediators involved in the regulation of important physiological functions in mammals."

So what do you guys think about this novel endogenous opiate?