This sounds like you're doing research. You're trying to gather data on daily habits and interventions taken by subjects and then looking at the impact on their

This sounds like you're doing research. You're trying to gather data on daily habits and interventions taken by subjects and then looking at the impact on their blood marker levels. That is normally something that would happen in a randomized controlled trial or possibly epidemiological retrospective if you're doing pure data mining, and the research subjects would at worst be volunteers, but might even be paid. This feels like you're asking research subjects to pay to be research subjects so they can take your treatments that you don't yet have evidence for. I don't mean to sound like I'm impugning your ethics, but why are you doing this as a startup and not a research proposal? Is it normal for YCombinator to fund medical research?