[collegeburner]

because the FDA are sticks-in-the-mud who get blowback when they approve something bad and but barely hear anything if they delay or restrict something good. there was also a to-do about celecoxib potentially increasing risk of heart attacks, plus the off-label marketing thing that led to the largest (at the time) settlement of that sort in history.

the process was also crazy complicated until some new 2020 legislation. the FDA published monographs saying things like "you can make a pain reliever with the following active ingredients and in the following forms." for example, no changes to the monographs on cough and cold medicines were made between 1987 and 2020. the new regime is of course a new mess to figure out, and consumers won't necessarily know the difference between a selective versus nonselective cox inhibitor. so you spend all this money and maybe inertia just keeps people buying ibuprofen and naproxen because it's what they know. and marketing something explicitly as "safer than ibuprofen" would be a massive hurdle to get cleared.

you can find all the FDA's monographs here, where it lists specific ingredients, concentrations, labeling, and testing procedures. https://dps.fda.gov/omuf/monographsearch