Isopure vs ON Gold Standard Whey

Two specific formulas. Prices and ingredients side by side.

Which should you choose?

Lowest cost per 25g: Optimum Nutrition Gold Standard 100% Whey Protein Powder Double Rich Chocolate at $1.62 per 25g protein, $0.32 less per equal protein portion than the other selected listing.

For an isolate-only whey formula: Isopure. For a whey blend: Optimum Nutrition.

Isopure · Creamy Vanilla · 3,401.9g pack · Price checked 2026-10-01.

Optimum Nutrition · Double Rich Chocolate · 2,268g pack · Price checked 2026-10-01.

Applies to these US listings. Check the retailer for the current price.

Selected formulas and US pack sizes
CompareIsopureZero Carb Whey Isolate Protein Powder Creamy VanillaCreamy Vanilla · 3,401.9gOptimum NutritionGold Standard 100% Whey Protein Powder Double Rich ChocolateDouble Rich Chocolate · 2,268g
Cost / 25g protein$1.94$1.62
Pack price$199.99 · 103 servings$114.99 · 74 servings
Price checked2026-10-012026-10-01
Protein / serving25g24g
Protein sourceswhey protein isolatewhey protein isolate, whey protein concentrate, hydrolyzed whey protein
Sweeteners in indexed listsucraloseacesulfame potassium
How we compare

Cost per 25g = pack price ÷ servings per pack × 25 ÷ protein grams per serving. For example, a $40 pack with 30 servings of 24g protein costs $1.39 per 25g protein.

Prices must have been observed within 45 days. We exclude unavailable listings, incomplete ingredient records, missing nutrition, and inconsistent serving or package weights. Taxes, shipping, subscription discounts, and checkout coupons are excluded. Serving counts may be calculated from pack weight and serving weight; displayed quantities are rounded to one decimal place, while calculations use the unrounded values. Check the retailer before buying.

Whey eligibility requires all identified protein sources to be whey. Mixed plant, casein, and collagen formulas are excluded.

Prepared from WheyIndex’s indexed product and source records. Read our scoring methodology. Rankings here use the stated metric; they do not use affiliate commission rates.

We select a chocolate listing where available, then vanilla, then another flavor. Within that group, we use the lowest eligible unit cost. This compares the displayed packs, not the entire brands.

Ingredients & label sources

Isopure Zero Carb Whey Isolate Protein Powder Creamy Vanilla

whey protein isolate, calcium phosphate, magnesium oxide, ascorbic acid, niacinamide, d-alpha tocopheryl acetate, zinc oxide, silicon dioxide, calcium d-pantothenate, vitamin a acetate, potassium iodide, manganese sulfate, chromium chloride, copper sulfate, pyridoxine hydrochloride, riboflavin, sodium molybdate, selenium, thiamine mononitrate, folic acid, cyanocobalamin, soy lecithin, natural and artificial flavor, sodium chloride, sucralose, xanthan gum.

Label processed: 2026-09-10

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Isopure vs ON Gold Standard Whey | WheyIndex