NutriStack
How to choose a supplement tracker.
A supplement tracker holds a list of everything you put in your body, which is an unusually sensitive thing to hand to an app and an unusually annoying thing to move once it is in there. The checks worth doing take ten minutes and mostly come down to whether the app shows its work.
Categories
Four different tools share one name.
Most disappointment with this category comes from buying one kind and needing another.
What each kind is built for
| Kind | Optimised for | Where it runs out |
|---|---|---|
| General reminder and habit apps | Not missing a dose | Knows nothing about what you are taking. A pill is a checkbox, so there is no awareness of combinations, forms, or amounts. |
| Product catalogs and rating apps | Choosing which bottle to buy | Rates products in isolation rather than your combination, and the rating is frequently a proprietary score with undisclosed weighting. |
| Web interaction checkers | A single one-off lookup | Not a routine, and usually built around drugs with supplements as an afterthought, so supplement-to-supplement coverage is thin. |
| Stack trackers | The routine and the combination together | Only as good as the underlying database, and only trustworthy to the degree it is honest about that database’s limits. |
Criteria
Nine questions worth asking.
In rough order of how much they matter and how quickly they can be checked.
The checklist
- Does it check combinations, or only catalogue items? Storing a list is easy. Reasoning about the list is the actual feature.
- Does it model prescription medication? Most supplement apps are supplement-only. Supplement-to-medication is where the documented literature is densest, so an app that ignores medication ignores the harder half.
- Can you click any claim and reach its source? A number with no visible provenance cannot be checked, corrected, or argued with.
- Is the methodology published? Look for the actual computation, not a paragraph describing that one exists.
- Who owns it, and what else do they sell? A rating platform owned by a company selling the rated products carries a structural conflict, whether or not any individual rating is affected by it.
- Does it work offline? A tracker that needs a connection to tell you what is in your own routine has put its database somewhere inconvenient.
- Can you export your data? Months of history that cannot leave is lock-in dressed as a feature.
- What happens to your health data? Look for a plain statement about selling, sharing and third-party analytics, not a privacy policy that avoids the question.
- What is genuinely free? Compare feature by feature. Headline price tells you very little about which of the features you came for sits behind the paywall.
Red flags
Signals that the tool is not showing its work.
None of these are disqualifying on their own. Several together usually mean the product is a rating engine rather than a reference.
Worth noticing
- A single numeric score with an undisclosed weighting, presented as objective.
- “Clinically proven” anywhere on a product page.
- No sources at all, or sources that are links to the app’s own other pages.
- A checker that returns nothing for a well-documented pair, or flags everything. Both are unusable, and the second is worse because it looks thorough.
- No statement anywhere of what the tool is not for. Every honest reference tool has a boundary and says where it is.
- Celebrity or practitioner endorsement doing the work that evidence should be doing.
This one
What NutriStack does, stated plainly.
The same criteria, applied to the app publishing this page.
Where it stands on each check
- Combinations. The interaction checker runs across everything in the routine at once, supplements and prescription medication together, rather than rating items individually.
- Sources. Records link to the published literature by PMID where one exists. The public evidence index shows the same attributed studies without installing anything.
- Methodology. The Stack Score formula is published in full rather than described. Read the methodology.
- Ownership. Independently owned. No manufacturer payments, no affiliate programs, no house brand. The subscription is the only revenue.
- Offline. The database is bundled with the app, so the routine and the checker work without a connection.
- Privacy. Health data is not sold. The privacy policy states what is collected and why.
- Free tier. The interaction checker, the routine and the score are free. The AI advisor is the paid feature.
The honest limitation, stated up front: NutriStack’s per-pair interaction assessments are not published to search, because they have not completed qualified human clinical review. What is published instead is the attributed literature index, which reports what studies exist and what their authors concluded without adding a verdict on top.
Questions
Common questions.
Short answers, and an explicit stop where the honest answer is “that depends on you and belongs with a clinician”.
Frequently asked
Do I need an app to track supplements?
No. A paper list works for remembering what you take. The case for an app is the part paper cannot do: checking the combination against a database, keeping a history you can actually search, and noticing when something new conflicts with something already in the routine.
Is a free web interaction checker enough?
For a single one-off lookup, often yes. The limits are that most are built around prescription drugs with supplements added later, so supplement-to-supplement coverage is thin, and none of them know your full routine, which is the context that determines whether any given pair matters.
Should a supplement tracker handle prescriptions?
The supplement-to-medication direction is where the published literature is densest and where the consequences are largest, so an app that models supplements only is leaving out the half that is hardest to reason about unaided. Whatever an app reports, the decision still belongs with a prescriber or pharmacist.
Can an app tell me whether my stack is safe?
No, and any app that says it can is overstating what a database can do. A tool can tell you what the published record contains for the combinations in your routine and can flag the ones worth raising. Whether a routine is appropriate for a specific person depends on their medical history, kidney and liver function, pregnancy, and everything else they take, which is a clinical judgement.
What should I look for in the privacy policy?
A plain answer to three questions: is health data sold, is it shared with third-party advertising or analytics services, and can you export and delete it. A policy that answers all three in specific terms is a better signal than one that is merely long.
Keep reading
The rest of the reference set.
Four more pages on the parts of a supplement routine that are factual rather than clinical.
The app
Apply the checks to this one too.
Published formula, source-linked records, no manufacturer payments, and an evidence index you can read without installing anything.