What is the most sold drug in the US?

I'm curious, what would you say is the most widely sold drug in the United States? It's a question that has likely crossed many minds, given the prevalence of drug use and the ever-evolving landscape of illegal substances. Could it be a traditional narcotic like heroin or cocaine? Or perhaps a more modern phenomenon, like the synthetic opioids that have been causing havoc in recent years? Whatever the answer may be, I'm eager to hear your thoughts on this topic.