What a drug interaction is
A drug-drug interaction is when one medicine changes how another behaves in the body, for example by raising or lowering its level in the blood, adding to a shared side effect, or reducing how well it works. Interactions are not all equal: many are minor and managed routinely, while a few can matter a great deal. The checker above compares the medicines you select against a public database of known interacting pairs and groups what it finds by how significant the source considers it.
Major, moderate and minor: what the labels mean
Can have a clinically significant, sometimes serious effect. The combination is usually avoided, or used only with close monitoring and dose adjustment.
Can matter in some people. Sometimes used, but usually with caution: monitoring, spacing doses apart, or adjusting the dose.
Usually of limited importance for most people, though still worth being aware of.
A severity label describes the interaction in general, not your personal risk. Your age, kidney and liver function, dose, timing and other medicines all change what an interaction means for you, which is why a pharmacist or prescriber is the right person to weigh it.
Why this is not a complete interaction check
No public dataset lists every possible interaction, and this one is no exception. It covers recorded drug-drug pairs only. It does not check interactions with food, alcohol, supplements or herbal products; it does not account for your dose, or for conditions like pregnancy or kidney disease; and a pair with no record here is not a guarantee of safety. Treat a clear result as a prompt to ask, not as a final answer.
If you find an interaction
Do not stop or change a prescribed medicine on your own; stopping some drugs abruptly is more dangerous than the interaction. Instead, write down everything you take, including over-the-counter products and supplements, and show the list to your pharmacist or doctor. They can confirm whether a combination is intended, adjust timing or dose, or suggest an alternative.
Questions people ask
- Is this interaction checker free?
- Yes. There is no account, login or paywall. You can check as many combinations as you like and share the result link.
- It found no interactions. Is the combination safe?
- Not necessarily. It means no interacting pair is recorded in our dataset, which is incomplete. Always confirm with a pharmacist, especially with new medicines.
- Why search by active ingredient and not brand?
- Interactions happen at the active-ingredient level. A brand can contain several ingredients, and the same ingredient is sold under many brands, so checking the ingredient is both more accurate and more complete.
- Does it check food or alcohol interactions?
- No. It covers drug-drug pairs only. Food, alcohol, caffeine and supplement interactions are not included.