I've never known any OTC analgesic to actually help with any aches or pains with the exception of it being a caffeine withdrawal headache and using Excedrin with Caffeine. But I could also just have some coffee or tea. Even strong prescription pain relievers like Vicodin or oxycotin barely have any effect. Novacaine works; but that makes the affected area entirely numb.
Maybe you have some kind of genetic drug resistance. My mom has an extremely high resistance to anesthetics (it's been a major problem when docs don't believe her) and apparently most people in my family do too.