Grass-Fed Whey Protein Isolate 25g (Unflavored)
A high-purity whey isolate delivering 25 g protein and a full leucine dose per serving. Protein supplementation augments strength and lean-mass gains when total daily protein is otherwise short.
Resar evidence panel
0–100 · cited research only
Evidence Score
81
Strong
Safety Score
53
Emerging
Effectiveness Score
76
Strong
Research Confidence
78
Strong
Product Fit Score
57
Emerging
Bottom line
Strong evidence (Strong) for nutrition — worth a closer look if this fits your goals.
Product fit is weaker — dose, price, or practical use may not align with what studies tested.
Evidence Score
81
Strong
Price
$59.99
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Compare others in NutritionTop research
The strongest studies behind this product
Ranked by evidence hierarchy and how closely each study matches this product. Start with the strongest study, then read down. Every claim needs a trail.
A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength
Meta Analysis · British Journal of Sports Medicine · 2018 · n=1,863
What the research shows
Clear added benefit to training when it raises total daily protein toward ~1.6 g/kg.
Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysis
Meta Analysis · The American Journal of Clinical Nutrition · 2012 · n=680
Nutrient timing revisited: is there a post-exercise anabolic window?
Systematic Review · Journal of the International Society of Sports Nutrition · 2013
Scores reflect these cited studies, not medical advice. Expand the full evidence detail below for protocols, dose context, and reported side effects.
Claim ledger
Every claim, mapped to its source
Each product claim below is tied to a specific paper with study type, match strength, and limitations. Nothing here is medical advice — it is a research trail you can audit.
Claim match reflects how closely a specific paper supports this benefit — not AI confidence or medical certainty.
Full evidence detail
Study-by-study breakdown
Each paper below is ranked for this listing. Start with the highest match, then expand any study for a plain-language readout.
How to read this section
- Match % - how closely the study matches this product (not overall scientific quality).
- Evidence type - study design (RCT, review, etc.) and whether it is direct, category-level, or indirect.
- What it found - short summary and quoted extract from the paper metadata. Not medical advice.
In plain language
What the study reported
Verified extract — not AI generated
“Clear added benefit to training when it raises total daily protein toward ~1.6 g/kg.”
Benefit tied to total daily protein; supplementing helps hit ~1.6 g/kg/day.
No adverse effects attributable to protein in healthy adults.
Caveats
Marginal benefit once daily protein needs are already met from food.
Transparency
Score history
Human review is pending for this listing.
Reviews
Shopper feedback
4.6
average rating
6,420 Amazon reviews were available from the listing metadata.