Supplement interaction checker.
See how your supplements interact — which work better together, which block each other's absorption, and how to time them. Evidence-based, no sign-up.
Add two or more supplements to see how they interact.
Covers supplement-to-supplement interactions. For interactions with prescription medications, talk to your doctor or pharmacist.
Does your stack actually work?
BioStacks scores every supplement on clinical efficacy — real doses vs. the research, not marketing. Scan a bottle and see.
Common combinations
Common questions.
Which supplements should not be taken together?
A few compete for absorption — for example calcium blocks iron, and zinc and copper compete. These aren't dangerous; you just get more from each by spacing them a couple of hours apart. Add your supplements above to see the specific ones.
Can I take all my supplements at the same time?
Usually yes. Most supplements have no meaningful interaction, so taking them together is fine. The exceptions are the absorption-competitors above — for those, split them across the day.
Does this check interactions with medications?
No — this tool covers supplement-to-supplement interactions only. Supplement–drug interactions can be serious, so for those talk to your doctor or pharmacist, or use a dedicated drug-interaction checker.
Is the interaction checker free?
Yes, completely free with no sign-up. For a full efficacy and safety score on a specific product, scan its label in the BioStacks app.