Last reviewed: July 19, 2026
Use WebMD or Drugs.com when your question involves a prescription or over-the-counter medication. Use NutriAudit when you want to check a supplement-only stack for ingredient interactions, duplicate nutrients, and dosage limits. No single checker replaces advice from a pharmacist or clinician.
If any medication is involved, start with WebMD or Drugs.com and confirm the result with a pharmacist. If your question is limited to vitamins, minerals, or herbs, NutriAudit can check supplement pairs and full stacks, including duplicate ingredients and regional upper intake limits.
| Feature | NutriAudit | WebMD | Drugs.com |
|---|---|---|---|
| Primary use | Supplement stack safety | Medication interactions | Medication interactions |
| Prescription and OTC medications | Not supported | Supported | Supported |
| Vitamins, minerals, and herbs | Supplement pairs and stacks | Alongside medicines and foods | Alongside drugs and conditions |
| Duplicate ingredients across a stack | Included | Not the primary use | Not the primary use |
| Dose limits across regions | US, EU, AU, China, Japan | Not the primary use | Not the primary use |
| Best fit | A supplement-only routine | A routine involving medicines | Detailed medication screening |
This comparison describes tool scope, not clinical quality. If a medication appears anywhere in your routine, do not rely on a supplement-only checker.
Choose two vitamins, minerals, or herbs to check their interaction. For a larger routine, use the full stack checker after reviewing the pair result.
Run this exact checkFree. No account required. Do not use for medication decisions.
Add multiple supplement ingredients and doses to look for pair interactions, duplicate nutrients, and upper-limit concerns in one report.
Open the full stack checkerFeature scope was checked against the official WebMD Drug Interaction Checker and Drugs.com Drug Interaction Checker on July 19, 2026.