The end result would be a website that provides a comparison similar to how this spreadsheet does it for Omega 3 supplement https://docs.google.com/spreadsheets/d/1vQcLEAPk5lcg-4YR_dwD...
This is to say that ads and sponsored listings would play little role in something that effectively allows to compare supplements based on their ingredients.
I have no doubt that it would be useful to some people... My bigger concern is if there is a business here worth pursuing. Not exactly cheap to run (would require a lot of manual input and/or AI). Not a lot of defensibility (could be scraped by someone).