How We Rate Evidence
Our scoring system uses a multi-factor weighted algorithm to objectively evaluate supplement research. Every score is computed automatically from the raw study data — no human bias, no cherry-picking.
The Scoring Pipeline
Each supplement's evidence score flows through four stages. Every individual study is scored, then scores are aggregated with a confidence adjustment.
1 Study Design Quality
Not all studies are equal. A double-blind, placebo-controlled trial carries far more weight than a case study. We assign a multiplier based on the study's methodological rigor.
2 Study Type
Human clinical trials are the gold standard for supplement research. Animal and in vitro studies provide supporting evidence but can't be directly applied to humans.
Human Study
Full weight. Clinical trials, cohort studies, and human observational data.
Animal Study
Half weight. Useful for understanding mechanisms but may not translate to humans.
In Vitro
Low weight. Lab cell studies provide early signals but are far from clinical proof.
3 Sample Size Scaling
Larger studies are more statistically reliable. We use a logarithmic scale so that going from 10 to 100 participants matters more than going from 1,000 to 10,000.
4 Outcome Analysis
We scan each study's results text for statistically significant language to determine whether findings were positive, negative, or mixed.
Positive
Study found statistically significant benefits.
Mixed
Both positive and negative signals found.
Unknown
Results text doesn't contain clear signals.
Negative
Study found no significant benefit.
Putting It All Together
Each study gets a weight (design × type × sample size) and an outcome score (0 to 1). These are combined into a weighted average, then adjusted for confidence.
Evidence Level Thresholds
The final score maps to one of four evidence levels.
Limited or no human clinical trials. Evidence may come only from animal or in-vitro studies.
Some human evidence exists, but results are mixed or studies have limitations.
Multiple well-designed human studies show consistent positive results.
Extensive body of high-quality human research with consistently positive outcomes.
Human Evidence Requirement
Confidence is primarily driven by human clinical data. Animal and in-vitro studies inform mechanisms but cannot replace human trials.
Evidence is capped at Weak regardless of how many positive animal studies exist.
Evidence is capped at Moderate. Some human data exists but the majority comes from non-human models.
Strong and Very Strong ratings require meaningful human clinical evidence.
Transparency & Limitations
Fully Automated
All scores are computed algorithmically from the study data. No manual overrides, no editorial bias.
Not Medical Advice
These scores summarize research trends. They are not recommendations. Always consult a healthcare professional.
Keyword-Based Outcome Detection
Outcome scoring relies on text pattern matching, which may miss nuance.
Living Database
Scores update automatically as new studies are added. Evidence levels can change over time.
