I Built a Free Herb-Drug Interaction Checker — Here's What I Learned About Health Data

Why I Built This Last year, my grandmother was taking warfarin (a blood thinner) and started drinking chamomile tea daily because she read it was "calming." What she didn't know — and what her doctor didn't mention — is that chamomile can increase warfarin's anticoagulant effect, raising the risk of dangerous bleeding. This isn't rare. A 2019 systematic review found that 40% of adults in the Americas use some form of herbal supplement, and many don't tell their doctors. The interaction data exists in PubMed — it's just not accessible to regular people. So I built an herb-drug interaction checker that anyone can use for free. No signup, no ads. Here's what I learned building it. The Data Problem The first challenge was sourcing reliable interaction data. There's no single "herb-drug interaction API." The data lives in: PubMed — 35+ million papers, but no structured interaction database Natural Medicines Database — comprehensive but costs $1,500/year WHO monographs — authoritative but co