Protein Purity Comparison Chart
Use the chart below to find transparent and objective readings on purity, leucine, and lactose for many popular protein brands.
| Brand / Product | Flavour | Protein Purity | Leucine Level (g/20g) | Lactose Level (mg) | Info | |
|---|---|---|---|---|---|---|
| Gruppo RAW Whey Protein Isolate | Flavourless | 93.50% | 2860 | 56 | + | |
| Naked Whey Grass-Fed Isolate | Flavourless | 92.60% | 3050 | 100 | + | |
| Klean Athlete Klean Isolate | Flavourless | 89.70% | 2075 | 500-1499 | + | |
| ISOPURE Unflavoured Protein | Flavourless | 86.20% | 2240 | 0 | + | |
| Momentus Essential Grass-Fed Whey Protein | Flavourless | 85.80% | 2480 | >500 | + | |
| Now Sports Whey Protein Isolate | Flavourless | 85.70% | 2079 | 500-1499 | + | |
| Nutricost Whey Protein Isolate Powder | Flavourless | 85.70% | * | 500-1499 | + | |
| Wicked Protein | Flavourless | 85.20% | 2074 | <21.4 | + | |
| Transparent Lab Grass-Fed Whey Protein Isolate | Flavourless | 84.10% | * | 500-1499 | + | |
| Ascent Whey Protein | Flavourless | 83.30% | 2080 | 1500-2499 | + | |
| Levels Whey Protein | Flavourless | 78.10% | 2080 | 2000 | + | |
| PE Science Select Protein Powder | Flavourless | 78.00% | * | 1500-2499 | + |
Protein purity percentage calculation data, as well as leucine and lactose values are taken directly from publicly-available, manufacturer-provided sources. * indicates that no value is readily disclosed or available. Colour coding for relative reference only. Dark green indicates a value in the top 10% of tabular purity data rankings; light green, a value in the top 30%; yellow, a value between 20% and 50%; and red, a value in the bottom 20% of tabular purity data from select protein brands. See * below for further info.
Frequently Asked Questions
How do you calculate protein purity? Protein purity percentage for unflavoured protein blends is calculated as amount of protein divided by the serving size.Why does leucine in protein matter? Many of the most prominent protein/muscle health researchers conclude that a minimum of 2.5 g of leucine is required to optimally trigger muscle protein synthesis. 2.5 g of leucine can be obtained through foods abundant in leucine. If looking for optimum muscle health, look for higher purity protein (>90% protein purity) and specifically proteins that deliver at minimum of 2.5 g Leucine / 20 g serving.
Why does lactose level in protein matter? There are two major benefits to having near zero lactose levels in whey protein powders: First, taste and texture are optimized; the higher the protein purity, the lower the lactose level. Whey proteins containing the lowest lactose levels will have the best taste and texture (not grainy and chalky), and are extremely easy to mix. Second, the lower levels of lactose, (look for 100 mg or less) will be suitable for folks that have a lactose intolerance and will not result in any gastrointestinal (GI) distress which can show the following symptoms: bloating, nausea, diarrhea, constipation, and abdominal pain.
An important note about "zero lactose" or "lactose-free" labeling: Some whey isolate brands put "lactose-free" on the label; this definition may be due to generous rounding. Specifically, the FDA doesn't have a formal definition of "lactose-free" for protein powders, so companies test below 1% and call it zero.
Why do some companies only offer flavoured whey proteins? When protein purity is low (lower than 90%) taste and texture (grainy, chalky) are negatively impacted. Adding flavours, gums and artificial sweeteners can cover protein off notes.
DISCLAIMER: Gruppo Nutrition is, in no way, affiliated with any of the above companies or products. All trademarks, service marks and company names are the property of their respective owners. We make no claim to efficacy of products listed above per individual athlete. Indeed, many of the products listed above are high-quality and exceptional in their own regard. We have made every effort to present the comparison in a clear, transparent, and objective manner based on information directly advertised or offered by the product manufacturers. *Data as of 03/05/2025; values may have changed since last update. Please confirm with manufacturer(s) before use or purchase choices.
