Yes, I am skeptical because even the most minor drugs have side effects. Something as small as Advil comes with potential headaches, so how can a drug come with none at all. It seems that the research has not be conducted properly here and the drug should not be released until all side effects are proven.
Although the natural products morphine and codeine, and the semi-synthetic drug heroin, are more reliably effective analgesics than raw opium, they retain its liabilities. Despite the introduction of potent synthetic opioid agonists like methadone and fentanyl ... developing analgesics without the drawbacks of classic opioids has remained an elusive goal
Yes, I'm skeptical about the claim that any new drug would have no side effects whatsoever. That seems unlikely. Perhaps not enough research has been done to discover possible side effects. Perhaps not all cases have been studied. Maybe researchers need more time to fully see the effects of the medicine. If the "no side effects" conclusion does prove true over time, this would be great!
The irony of medicine is that the side effects are usually more worse than the actual illness they supposedly cure. Now when they say they've got a new pain killer with no side effects I have to admit it does sound too good to be true and like they always say, "If it sounds too good to be true, more often than not it usually is." But, I'll hold out hope.