Drug Interaction Checkers
Catch dangerous combinations before they hurt.
Drugs.com Interactions
FREEBest free interaction checker. Type meds, get severity-rated warnings.
Best free.
Medscape
FREEPro-grade tool. Used by doctors. Free with signup.
Best clinical.
WebMD Drug Interaction Checker
FREEFamiliar UI. Senior-friendly explanations.
Best for seniors.
Apple Health Medications
FREEiOS 16+ flags interactions automatically.
Best built-in.
GoodRx app
FREEHas interaction checker + price comparison.
Best with prices.
Your pharmacist
FREEBest interaction-checker walks behind any counter. ASK.
Best human.
Common dangerous interactions
- Blood thinner (Warfarin/Eliquis) + ibuprofen/aspirin — bleeding risk.
- Statin + grapefruit — affects metabolism, can be toxic.
- Antidepressant + St. John's Wort — serotonin syndrome.
- Multiple anti-anxiety / sleep meds — over-sedation, fall risk.
- BP medication + decongestants — spike blood pressure.
- Insulin / diabetes meds + alcohol — dangerous lows.
- Ginkgo + blood thinners — increased bleeding.
Don't forget OTC + supplements
- Aspirin + blood thinners.
- Tylenol — too much can damage liver, especially with alcohol.
- Decongestants (Sudafed) — raise blood pressure.
- Antihistamines (Benadryl) — increase fall risk in seniors.
- Vitamin K + blood thinners — affects effectiveness.
- Fish oil + blood thinners — bleeding risk.
- St. John's Wort — interacts with MANY meds.
Pharmacist is free + best
Walk into Walgreens / CVS / Costco. Hand pharmacist your medication list. Ask "any concerning interactions?" Free service. Better than any app. Pharmacists are medication experts AND they have access to your prescription history.