How We Score Effectiveness

We assess effectiveness evidence on three dimensions: the level of evidence (cell studies, animal studies, human trials), the quality of evidence (study design, sample size, replication), and consistency (whether multiple independent studies reach the same conclusions).

Each dimension is evaluated to assign an overall effectiveness rating.

Level 1: Randomized controlled human trials in relevant populations. Level 2: Non-randomized human studies or smaller trials. Level 3: Animal studies. Level 4: Cell culture or in vitro studies. Level 5: Theoretical or mechanistic considerations with no empirical support.

Higher levels receive more weight in our assessment.

We assess: study design (randomized vs non-randomized), blinding (double-blind superior), sample size (larger is stronger), study duration (longer allows detection of sustained effects), outcome measurement (objective vs subjective), and conflict of interest.

High-quality large trials from independent groups carry much more weight than small, manufacturer-sponsored studies.

Findings replicated across multiple independent studies in different populations are more credible than single studies. Conflicting results lower confidence. Consistent findings from heterogeneous populations strengthen confidence in effectiveness.

We synthesize the evidence and assign an effectiveness rating: Strong (consistent high-level evidence), Moderate (mixed evidence or moderate-level evidence), Weak (preliminary evidence or single studies), or Insufficient (limited evidence). These ratings are explicitly stated in each peptide review.