Methodology
Last updated: July 2026
This page describes how Nous Vita evaluates supplements, checks for drug interactions, and grades evidence. We publish it so that users, clinicians, and researchers can assess our work critically. Transparency is the foundation of trust, and trust is all we have.
Data Sources
Nous Vita draws on multiple authoritative sources. We do not use marketing materials, manufacturer claims, or affiliate content as evidence.
NIH LiverTox Database
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) maintains LiverTox, a comprehensive clinical and research database on drug-induced liver injury. It covers over 1,000 prescription and nonprescription medications, herbal products, and dietary supplements. Each entry includes the likelihood of liver injury, clinical patterns, case reports, and severity classifications. We cross-reference every supplement in a user's regimen against LiverTox to flag known hepatotoxic risks. LiverTox is in the public domain; use of its data is acknowledged per NIDDK attribution guidelines.
Published Drug Interaction Studies
supplement drug interactions are sourced from peer reviewed clinical literature: PubMed indexed studies, case reports, systematic reviews, and meta-analyses. We prioritize human pharmacokinetic studies and clinical case reports over in vitro or animal data. Each interaction record includes at least one citation. Interactions are categorized by mechanism (pharmacokinetic, pharmacodynamic) and clinical severity.
Clinical Guidelines and Regulatory Sources
Where available, we incorporate guidance from FDA drug labels, European Medicines Agency assessments, and clinical practice guidelines. These sources provide additional context for severity classification and clinical recommendations.
Evidence Grading
Every supplement recommendation and safety claim carries an evidence grade. We use a three tier system adapted from standard evidence-based medicine frameworks.
High
Supported by multiple randomized controlled trials with consistent findings, or a systematic review/meta-analysis. The effect is well characterized, and the direction of evidence is clear.
Moderate
Supported by at least one randomized controlled trial or multiple well designed observational studies. The evidence is suggestive but not conclusive. Effect sizes may vary across studies.
Low
Supported by mechanistic plausibility, animal studies, or preliminary human data only. The claim is biologically plausible but has not been confirmed in rigorous human trials.
How the Safety Checker Works
When you enter supplements and medications into Nous Vita, the Safety Checker performs two types of analysis, both running entirely in your browser.
First, it checks each supplement against the NIH LiverTox database for known hepatotoxicity. Supplements are assigned a LiverTox category (A through E, or X for unknown) which reflects the likelihood of drug-induced liver injury. Results include the specific LiverTox classification and a link to the source entry.
Second, it checks each supplement against each medication for known interactions using our curated interaction database. An interaction is reported when published evidence documents a clinically meaningful effect: altered drug absorption, metabolism, or clearance; additive or antagonistic pharmacodynamic effects; or documented adverse events. The checker reports the mechanism, the direction of the effect, and the citation.
Nous Vita works like an application on your device. Once the site has loaded, you can disconnect from the internet and everything still works: the safety checker, the regimen builder, the tracking dashboard. The interaction database is part of the site itself, loaded once at build time, not fetched from a server while you use it. No internet connection needed. In the future, if we offer optional encrypted cloud backup, that is the only feature that would need a connection, and it would be opt-in only.
Research Pipeline
We maintain an adversarial research pipeline to keep the knowledge base current and honest. New evidence is evaluated by multiple independent reviewers who are incentivized to find weaknesses in the evidence, not just support for existing conclusions. We explicitly look for studies that contradict our current assessments. When the evidence shifts, we update our recommendations and publish the rationale for the change. The pipeline includes systematic monitoring of PubMed for new supplement drug interaction publications, regular review of NIH LiverTox updates, and periodic re evaluation of existing evidence grades.
Limitations
Nous Vita is an informational tool, not a substitute for clinical judgment. Our analysis has important limitations that users and clinicians should understand.
The interaction database covers published, documented interactions. It does not cover theoretical interactions that lack published evidence, interactions with rare or newly approved medications that have limited post marketing data, or individual patient factors such as genetics, liver function, age, or polypharmacy burden. A result of no known interactions does not guarantee safety. The absence of evidence is not evidence of absence.
The NIH LiverTox database, while authoritative, reflects published case reports and clinical studies. Rare or novel hepatotoxic reactions may not yet be documented. The database also does not account for individual susceptibility factors.
Supplement quality and composition vary by manufacturer. Nous Vita evaluates the substance, not specific brands. A product may contain fillers, contaminants, or different doses than labeled.
Updates and Versioning
The interaction database and evidence grades are updated as new research is published. Major updates are versioned and changelogs are published. The NIH LiverTox data is refreshed when NIDDK releases updates. Users can verify the last update date on this page.