Klean Athlete Klean Isolate
Professional and Olympic athletes who need NSF-certified protein with pharmaceutical-grade purity
Optimum Nutrition Gold Standard 100% Whey
Budget-conscious gym-goers who want proven, great-tasting protein at the best value
Score Comparison
Pricing & Features
Making Your Decision
When to Choose Klean Athlete Klean Isolate
Professional and Olympic athletes who need NSF-certified protein with pharmaceutical-grade purity
Klean Athlete is purpose-built for competitive athletes who cannot risk contamination. NSF Certified for Sport plus pharmaceutical-grade manufacturing standards make it one of the safest protein powders available. The unflavored single-ingredient option is ideal for purists.
Strengths
- NSF Certified for Sport — trusted by Olympic and professional athletes
- Single-ingredient unflavored option available for maximum purity
- Made by supplement industry leader (Atrium Innovations) with pharmaceutical-grade standards
Limitations
- Flavored options (Vanilla, Chocolate, Strawberry) are less sweet than mainstream competitors
- Only 20 servings per pouch at $2.20/serving is expensive
- Limited retail availability — primarily sold through specialty channels
When to Choose Optimum Nutrition Gold Standard 100% Whey
Budget-conscious gym-goers who want proven, great-tasting protein at the best value
Gold Standard has been the world's best-selling protein powder for over a decade, and the value proposition is hard to beat — 74 servings at $1.08 each with Informed Choice certification. The trade-off is artificial ingredients and a whey blend rather than pure isolate.
Strengths
- Informed Choice certified — the most popular protein powder worldwide for a reason
- Outstanding value at $1.08/serving with 74 servings in the 5lb size
- Excellent taste and mixability across 20+ flavor options
Limitations
- Contains artificial flavors (acesulfame potassium) and soy lecithin
- Uses whey blend (isolate, concentrate, peptides) rather than pure isolate
- Does not publish independent lab test results or batch-level COAs
