Do your supplements clash with your medicines?
Add the supplements and medicines you take and the Stack Checker maps any known interactions between them, graded by how serious they are and how strong the evidence is. Then print a summary for your pharmacist.
Free accountNo cardUnder a minute to join
See it in action
Your whole stack, on one map
Bubbles are the things you take. Lines are known interactions, coloured by severity, with a card for every finding.
Try it yourself →What you get
Everything in the Stack Checker
An interaction map
See your whole stack at a glance: what interacts with what, and how seriously.
115 supplements, 30,000+ medicines
Search supplements, prescription medicines and brand names.
Severity and evidence for each finding
Know whether it’s a major interaction backed by strong evidence, or a minor one from a single study.
A printable summary for your pharmacist
Take it to your pharmacist or GP and have a better conversation.
Save your checks
Keep your list of supplements and medicines and re-run it when something changes.
Private to you
Your checks are stored in your account, not shared or sold.
How it works
Three steps, about two minutes
- 1
Add what you take
Start typing a supplement, medicine or brand name.
- 2
See your interaction map
Every known interaction, graded by severity and evidence.
- 3
Talk to your pharmacist
Print or save the summary and take it with you.
Why you can trust it
Independent, evidence-based, on your side
- Interaction data from Examine, the independent supplement research database
- Anything we can’t check is labelled “not checked”, never “safe”
- Built and run by an independent non-profit: no supplements to sell you
foodfacts.org is an independent non-profit that fact-checks food and nutrition claims. We take no advertising and no money from the food industry.
Try it free →Questions
Can supplements interact with medicines?
Yes. Some supplements change how medicines are absorbed or how they work, and a few combinations can be serious. That’s why it’s worth checking, and telling your pharmacist or GP what you take.
Is the Stack Checker free?
Every free member gets a check each month. Supporters (£5 a month) get up to 30 checks a month.
Does “no interactions found” mean it’s safe?
No. It means no known interaction was found in the data for that combination. Always check with a pharmacist or GP before starting, stopping or combining anything.
Where does the data come from?
From Examine, an independent research database that grades every interaction by severity and the strength of the evidence.
Is this medical advice?
No. It’s an information tool to help you have a better conversation with your pharmacist or GP.
Free with the same account
More tools for members
Ready?
Do your supplements clash with your medicines? Find out in two minutes.
Create your free foodfacts.org account and you’ll go straight into the Stack Checker.
Try the Stack Checker free →
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