How to Check Medication and Supplement Interactions

The fastest way to answer "can I take these together?" is to check the specific pair rather than search generically. Here is exactly how the checker on this site works, and how to read what it tells you.

1. Search and select each item

Open the checker and click into the search field -- it opens a full list of every substance currently eligible for checking. Type to filter, or scroll. Select the first item, then the second (and more, if you are checking a larger stack). Only substances with a completed evidence review against your other selections will appear as you add more -- this is deliberate: the checker will never let you build a combination it cannot actually speak to.

2. Read the classification, not just the color

Every reviewed pair is labeled with both an icon and a text badge -- never color alone. The four real classifications used on this site are:

• Avoid -- a documented reason these generally should not be combined without a clinician's guidance.
• Use caution -- a documented interaction that warrants care, such as dose adjustment or spacing.
• Monitor -- a documented interaction worth watching for, such as a lab value or symptom.
• Informational / no documented interaction identified -- no clinically significant concern was found in the sources checked for that specific pair.

See Important Interactions for every currently reviewed avoid/caution/monitor pair in one place.

3. Check the evidence quality and sources

Each result also shows an evidence-quality badge (high, moderate, low, or insufficient) -- this is a separate axis from severity on purpose. A well-documented mild interaction and a poorly-documented serious one look very different, and collapsing that distinction would hide real uncertainty. Every published result links to the real sources behind it (FDA/DailyMed labeling, NIH fact sheets, clinical guidelines, or peer-reviewed research) so you can read the primary source yourself.

4. What if the pair hasn't been reviewed yet?

The checker will say plainly: "we do not currently have a reviewed interaction record for this pair." That is never converted into an implicit "safe." It means our review process has not yet reached that specific pair -- see what "no documented interaction identified" means for the distinction between that and an unreviewed pair.

5. Check timing too, not just interactions

A pair can have no direct interaction and still have a timing consideration worth knowing -- certain minerals binding to certain medications in the gut, for example. When you check a stack, any reviewed timing/spacing rule for it appears alongside the interaction results. See Timing & Absorption for the sourced windows on record.

None of this replaces individualized medical advice -- see the medical disclaimer. For a specific concern, a pharmacist or clinician can account for your dose, formulation, and other medications in a way a general reference cannot.