How We Rate
We rate every product the same way, on six things anyone can check: the evidence, the dose, the form, the certification, the label and the value. We work from the label, the published research, the certifiers' public databases and current prices, so every score traces back to a source.
1.
Evidence. How strong is the research for this ingredient, for the use on the label? We grade it A to D, starting with the strongest human research we can find: systematic reviews, meta-analyses and randomized controlled trials. If the label promises more than the research shows, it loses a point.
2.
Dose. Does one serving give you the amount used in the studies? We put the label dose next to the study dose. If it takes two scoops or four capsules to get there, we say so, and the Value score counts it.
3.
Form. Is it the form the research actually tested? When the studies used one form and the bottle holds another, the score drops unless that form has good evidence of its own.
4.
Certification. Does it carry NSF Certified for Sport, Informed Sport or USP Verified certification? We search the certifier's public database ourselves and link the listing. A brand's own "tested" badge doesn't count. No listing, and we say so.
5.
Label. Can you see every ingredient and its amount? Proprietary blends that hide their doses lose points. You can't check a dose you can't see.
6.
Value. What does one study-matched dose cost? We compare the cost per effective dose across at least three brands, not the cost per tub, and we date every price.
How the score works. Each criterion gets a score from 1 to 5. The overall score is the average of the criteria that apply to that product, rounded to one decimal, and every review lists which ones apply. Scores reflect the label, the research, the certifications and the prices on the date shown in the review. What we don't do. We don't run lab tests, and we don't score a product on how it made us feel, because one person's experience isn't evidence. If a review ever uses an independent lab, it says so and links the report.
What our evidence grades mean
Every ingredient claim in a review gets a grade. A grade covers one ingredient and one use, so the same ingredient can earn an A for one goal and a C for another.
The grade drives the Evidence score. A label that promises more than its grade supports loses a point.
A
Strong. Consistent results across several randomized controlled trials, pulled together in a systematic review or meta-analysis, in people like the ones the label is aimed at.
B
Good. Several randomized trials point the same way, but they are small, short or not fully consistent.
C
Early. A few small trials, mixed results, or studies in a narrow group that may not look like you.
D
Little or no support. Mostly animal, cell or observational studies, or good trials that found no meaningful effect.