Legion Whey+ Grass-Fed Whey Isolate Review

Two things, and both are verifiable. First, the label is fully disclosed with no proprietary protein blends — you can see exactly what's in the tub and in what amount, with no number hidden behind a blend. Second, it's independently tested in an ISO 17025 accredited lab and certified by Labdoor to be free of contaminants and banned substances. That's a named, third-party certification — a stronger testing signal than Gold Standard, whose listing states "None stated". Transparent Labs (#2) has specific lots on the NSF Certified for Sport list, and Ascent (#3) states Informed certification per the brand. If knowing exactly what's in the tub, and that an independent lab verified it, is what you care about most, this is the pick.

22 g is a touch lower than the 24-28 g picks ranked above it (Gold Standard 24 g, Ascent 25 g, Transparent Labs 28 g) — it's the main reason Legion sits at #4 despite leading on trust. In practice the gap is small and easily closed: a slightly heavier scoop, or pairing the shake with any whole-food protein, makes it a non-issue for hitting a daily target. You're trading a couple of grams per scoop for a fully disclosed, Labdoor-certified label. For most buyers that's a fair trade if transparency is the priority.

Legion is naturally sweetened with stevia plus erythritol, a sugar alcohol, instead of artificial sweeteners like sucralose. The upside: no artificial sweeteners and 0 g added sugar. The downside: erythritol is a sugar alcohol that some people tolerate poorly, occasionally causing bloating or GI discomfort in sensitive individuals. If you know sugar alcohols don't agree with you, a stevia-only pick like Transparent Labs (#2) or Ascent (#3) may sit better. If erythritol is fine for you, Legion's naturally sweetened, fully verified label is a strong combination.

Only if verified transparency is your priority. At about $1.67 per serving in a 30-serving tub, Legion costs notably more per serving than our #1, Optimum Nutrition Gold Standard (~$0.95). What the premium buys is a fully disclosed, grass-fed, naturally sweetened isolate that an independent ISO 17025 lab and Labdoor have verified. If you want certainty about exactly what you're drinking, that's worth paying for. If you mainly want affordable, reliable protein and trust the brand's track record, Gold Standard wins on value.

Both carry named third-party certifications, which puts them ahead of most of this lineup on trust. Legion is Labdoor-certified and tested in an ISO 17025 accredited lab, with a fully disclosed, flavored, naturally sweetened isolate. Naked Whey (#5) is NSF Certified and tested for heavy metals, but it's a single-ingredient unflavored concentrate — you flavor it yourself. The choice comes down to format: Legion if you want a ready-to-drink flavored isolate with a verified label; Naked Whey if you want the absolute minimalist NSF-certified base and don't mind flavoring your own shakes.

1. [1] Morton 2018 PMID 28698222 — A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Meta-analysis of 49 studies (1,863 participants): protein supplementation significantly augmented resistance-training gains in muscle mass and strength, plateauing around 1.6 g/kg/day. Context for why even a slightly lower 22 g scoop is fully effective when it helps you reach that daily target.
2. [2] Cermak 2012 PMID 23134885 — Protein supplementation augments the adaptive response of skeletal muscle to resistance-type exercise training: a meta-analysis. Pooling 22 RCTs, supplemental protein during resistance training significantly increased fat-free mass, fiber cross-sectional area and 1-RM strength. The core evidence that a quality verified isolate is a legitimate training tool.
3. [3] Cintineo 2018 PMID 30255023 — Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training. Review concluding adequate total daily protein supports performance, recovery and adaptation, with peri-exercise timing a useful but secondary factor. Reinforces that a trusted, verified protein's job is to help you hit a daily target consistently.