Why I built this
Elthio started as something much smaller: a tool to find the best price on supplements across iHerb, Life Extension, and other retailers. I wanted to know — am I overpaying for magnesium? Is this CoQ10 actually a good deal compared to that one?
While building that, I kept running into the same question from people testing it: "this is great, but is it actually safe for me to take with my other medications?"
That question turned out to matter a lot more than the price. I started digging into drug-supplement interactions and realized something surprising — most free tools either don't check supplement interactions at all, or only check one supplement against one drug at a time. Nobody was looking at a person's full stack — all their medications and all their supplements together — and explaining what that actually meant in plain English.
So Elthio became that. The price comparison is still there (that's how this site stays free, through small affiliate commissions when you buy something — more on that below), but the core of Elthio now is making sure what you're taking together is actually safe, and helping you understand why.
What Elthio checks
Every Med Check runs your medications and supplements against:
- 334 curated interaction rules — sourced from the NIH Office of Dietary Supplements, the NIH National Center for Complementary and Integrative Health, and peer-reviewed journals. Every rule shows its source and evidence strength.
- FDA adverse event data (FAERS) — real reports from real patients who experienced side effects combining specific drugs and supplements.
- NIH ingredient verification (DSLD) — checks whether a product's label actually matches what's registered with the NIH Dietary Supplement Label Database.
- Semantic search — you can describe your situation in plain English ("I take a blood thinner and want to try turmeric") and Elthio understands what you mean, even without exact drug names.
What Elthio is not
I want to be straightforward about this:
- Elthio is not a substitute for medical advice. It's a research and awareness tool. Every result includes sources so you can verify them yourself and bring questions to your doctor or pharmacist.
- The interaction database is not exhaustive. 334 rules covers the most common and clinically significant combinations, but it's not every possible interaction. Professional databases like DrugBank have thousands more — expanding coverage is ongoing.
- The AI explanations are AI-generated. Claude (Anthropic's AI) synthesizes the rule data and FDA reports into plain English. The underlying rules and sources are fixed and citable. The explanation text is generated and, while designed to be accurate and conservative, can occasionally be imperfect — which is why every source is shown so you can check the original.
- No part of Elthio has been formally reviewed by a licensed pharmacist yet. This is something I'm actively working on. If you're a pharmacist or have clinical experience and want to help review the rule database, I'd genuinely love to hear from you — get in touch.
How Elthio makes money
Elthio is free and always will be for the core safety check. The price comparison feature includes affiliate links — if you buy something through Elthio, I may earn a small commission at no extra cost to you.
This commission never affects what Elthio recommends. Safety rankings are based purely on NIH verification and interaction data. Price rankings are based purely on cost per serving. If a product is a better deal or safer, it shows up higher — regardless of commission.
Your privacy
Elthio doesn't require an account to use. If you choose to save your stack for weekly safety updates, your email and stack data are stored securely and never sold or shared. You can delete your data at any time by contacting me. Shared stack links never show your email publicly.
Questions or feedback?
If something seems wrong, missing, or could be better — please tell me. This is a tool I'm building because I think it's genuinely useful, and feedback directly shapes what gets built next.
Get in touch →