How do different pain killers target different areas despite having the same basic ingredients?
Sometimes they have different amounts of each ingredient. Certain ingredients are better for different types of pain
If the ingredients are identical, it’s just marketing.
Here in Australia, Nurofen was fined millions of dollars for misleading consumers into thinking that differently branded (and priced) versions of ibuprofen were able to target specific pain areas.
Not an Expert, but As I understand it, pain medicine doesn’t necessarily target a specific area. Instead what happens is the pain medicine works where there’s pain and you don’t notice the effects in other places. For example if your arm hurts and you take pain medicine the area where it hurts stops hurting but the areas that don’t hurt don’t feel any change.