Caffeine is popular, no doubt about it. National smoothie chain Tropical Smoothie Cafe offers caffeine as a “Energizer Supplement “ to any smoothie, and they don’t even mention the caffeine content. Just one example.
The company I work for has a division that maintains first aid cabinets in workplaces. When I train CPR/First Aid/AED classes for our customers I always check out their first aid cabinets and nurse offices to see their supplies so I know what to discuss in their training classes. The number one OTC pain med is generic Excedrin, which contains caffeine. If they run low on this they call and ask for it to be delivered ASAP. The Tylenol and Ibuprofen might expire because no one uses it because everyone wants the pain reliever that contains caffeine.
And when I worked in clinics and doctor offices and entered patient medication lists into their electronic charts, Excedrin or generic Excedrin was the most popular.
All of the major chains offer their brand of Excedrin. CVS, Walgreens, Walmart, Meijer, Kroger, etc. I’ve seen them all when patients brought in their bags of meds.