Free supplement + medication interaction checker

Will your supplements and meds interact?

Curated clinical interaction rules check any combination of supplements and medications for dangerous interactions — free, no account needed.

Free · No account needed · No ads, no affiliate links, nothing to sell you

Rules decide the warnings

A hand-written clinical rule set runs on every check — serotonergic pairs, blood thinners, potassium, thyroid minerals and more

AI only writes the explanation

It puts the analysis in plain English. The rules run after it and only ever add warnings or lower the score — never the reverse

Real label data

Milligram totals come from the NIH Dietary Supplement Label Database — the amounts printed on your actual bottles

The checker's dictionary covers 378 supplements and 140+ medication and brand names, and label milligram totals come from the NIH Dietary Supplement Label Database. How the analysis works.

How It Works

Three steps, no account, nothing to install

1
Enter Supplements

Type in your supplements or the ones you're considering

2
Rules, Then AI

Curated interaction rules check the combination; the AI writes up what they found

3
Get Results

A safety score, every flagged interaction, and a one-page doctor-visit report — free for everyone

Free tools — no subscription needed

Free, and staying free: unlimited interaction checks with no cap on how many medications you add, bottle scanning, Build My Stack, My Cabinet, your health profile, dose reminders with calendar export, the printable doctor-visit report, the shared-protocol checker, and 1,200+ supplement reference pages. Every interaction warning and every condition-specific warning is free for everyone — we don't sell safety, and there are no ads, no supplement sales and no affiliate links anywhere on the site.

Cabinet Watch

Checking is free. Watching is paid.

The checker stays free. Cabinet Watch is the version that remembers your cabinet, your meds and your conditions, and keeps re-checking them as the rules and your routine change

Unlimited Stacks

Save unlimited supplement combinations — all re-scored monthly with email alerts

Timing Schedules

Your whole stack on one daily schedule, with pairs that compete for absorption in separate slots

Advanced Safety

One standing view of your whole saved cabinet against your conditions — the warnings themselves are free on every check

Food & Absorption

Meals sequenced so your supplements absorb — shaped by your stack, goals, DNA, and your kitchen

DNA Analysis

Supplement recommendations matched to your genes — MTHFR, COMT, CYP1A2

Your Cabinet, Re-Checked

Every saved stack re-checked about monthly as the rules change — with an email when a score moves

Explore Cabinet WatchTry Food & AbsorptionCabinet Watch is $9.99/mo, or $59/yr with the $29 DNA report included. Cancel any time.
Included with Cabinet Watch · or $29 one-time

DNA-Based Supplement Notes

Upload your 23andMe or AncestryDNA file and we read 9 variants across 7 genes, then explain what each one does and does not mean for the supplements you take

Upload Your DNA File

Supports 23andMe, AncestryDNA, and other major DNA testing platforms. Your raw file is processed in memory and never stored.

Genetic Analysis

We read 9 variants across 7 genes — MTHFR, COMT, CYP1A2, VDR, APOE, FUT2 and BCMO1 — and show the rsID and the genotype found in your file for each one

Notes You Can Check

Plain-English notes on what each variant does and doesn't mean, with the reasoning shown. The $29 one-time report (also included with Cabinet Watch — Yearly) is yours to keep; on a monthly subscription access locks when the subscription ends. You can delete your stored results at any time.

DNA Report
Your raw file is read in memory and never stored — only the variant results, and only with your consent
$29one-time — no subscription
COMT Gene Analysis
MTHFR Variants
CYP450 Enzymes
Get Your DNA Report — $29

DNA analysis is included with Cabinet Watch ($9.99/mo or $59/yr). The keep-forever report is $29 one-time (free with Cabinet Watch — Yearly), with a 14-day money-back guarantee.

Check What You Already Take

No account, no ads, no affiliate links, and nothing for sale — the interaction checker is free and stays free

Check My Supplements — Free

CanIStackThis provides informational insights only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a healthcare professional before making supplement decisions.