It's no secret America is hurting right now. Life expectancy is in decline, fuelled by a deadly national addiction to painkillers that knows almost no bounds.

But a new experimental chemical compound developed by scientists in the US and so far tested on animals could be the ray of light so many desperately need.

Called AT–121, it's more powerful than morphine in delivering pain relief, it doesn't produce dangerous side effects, and – importantly – it's not addictive.

"In our study, we found AT–121 to be safe and non-addictive, as well as an effective pain medication," explains pharmacologist Mei-Chuan Ko from Wake Forest Baptist Medical Centre.

"In addition, this compound also was effective at blocking abuse potential of prescription opioids, much like buprenorphine does for heroin, so we hope it could be used to treat pain and opioid abuse."

Ko and fellow researchers developed AT–121 in their attempts to find a molecule that could act upon two key receptors in the brain: the mu opioid receptor, which conventional opioids and prescription painkillers target, and the nociceptin receptor, which regulates various brain activities, including feelings of addiction and chemical dependence.

In theory, an agonist that could successfully bind to both these receptors could promote sensations of pain relief without inviting the severe addiction that opioids often arouse.

"We developed AT–121 that combines both activities in an appropriate balance in one single molecule, which we think is a better pharmaceutical strategy than to have two drugs to be used in combination," Ko says.

Early results are positive. In tests with rhesus monkeys, AT–121 appeared to deliver pain relief equivalent to morphine, but at a dosage 100 times lower.

It also did so non-addictively, but more than that, when the compound was given to animals who had developed a dependence on the opioid oxycodone, it actually reduced their level of addiction, suggesting AT–121 might be able to help patients wean themselves off other drugs at the same time as treating their pain.

That, of course, is assuming the chemical works on humans the same way it does on monkeys. There's no guarantee of that, but the researchers are confident future work could show just that.

"The fact that this data was in nonhuman primates, a closely related species to humans, was also significant because it showed that compounds, such as AT–121, have the translational potential to be a viable opioid alternative or replacement for prescription opioids," Ko explains.

If that's the case, the drug could offer another benefit too. AT–121 didn't trigger respiratory depression (breathing difficulties) or cardiovascular issues even when given at high dosage, meaning we could be looking at an effective, non-addictive painkiller that's impossible to overdose on.

We'll need to see what results further studies produce, but with the ongoing tragedy of the opioid epidemic as a grave backdrop, it's hard to not get a little excited about the promise and potential here.

"I think this is pretty interesting," pharmacologist Bryan Roth from the University of North Carolina at Chapel Hill, who wasn't involved with the study, told Live Science.

"This is one of several of these types of studies that have been published recently that suggest there may be hope for creating safe medications for treating pain. It gives me hope for the field that we may be turning a corner."

The findings are reported in Science Translational Medicine.