How to Interpret an Interaction Result

Every reviewed pair on this site is labeled with two independent things: a severity (what the finding means practically) and an evidence quality (how strong the underlying sourcing is). Reading both together is what makes a result actually useful, rather than just a single scary or reassuring word.

Severity labels, from most to least serious

• Avoid combining -- the strongest label on this site. Reserved for combinations where authoritative sources document a serious risk and generally recommend against combining.
• Use caution -- a documented interaction exists and is significant enough that a prescriber or pharmacist should weigh in before combining, even though the sources don't frame it as an outright avoid.
• Monitor -- a documented interaction exists and the sourced guidance is to watch for a specific effect (like a lab value or symptom) rather than avoid the combination outright.
• Informational -- a real, sourced finding that isn't a caution at all -- for example, a study showing no clinically significant effect, or a positive/supportive interaction (like vitamin C improving iron absorption).
• Insufficient evidence -- used both for "no documented interaction identified" outcomes and for any pair where the available evidence genuinely doesn't support a confident severity call.

Evidence quality, separately from severity

Evidence quality (High, Moderate, Low, or Insufficient) describes how strong the sourcing behind a finding is -- for example, a finding named directly on an FDA drug label is generally stronger evidence than a single small study. A "monitor" finding backed by high-quality evidence and a "caution" finding backed by low-quality evidence are both real results, but they carry different confidence levels worth knowing separately from the severity word itself.

Reading a result correctly

A high-severity label with low evidence quality is not automatically more trustworthy than a lower-severity label with high evidence quality -- read both, not just the headline word. And a severity label is never a substitute for reading the actual summary and source citations on the pair's own page, which explain the specific mechanism and practical context behind the label.

What none of these labels mean

No severity label on this site -- including "informational" or "insufficient evidence" -- is a certification that a combination is safe for you personally. See What Does "No Documented Interaction Identified" Mean? for why that specific result deserves its own explanation, and the methodology page for how every label is assigned during review.

Check a combination to see these labels applied to a real result.