Optimum Nutrition Gold Standard vs Dymatize ISO100 (2026)
Gold Standard 100% Whey is a whey blend (isolate, concentrate and hydrolyzed whey); ISO100 is all whey isolate, part of it hydrolyzed. ISO100 carries a little more protein per scoop (25 g vs 24 g). Per 25 g of protein in the 5 lb tubs, Gold Standard is 7% cheaper ($1.45 vs about $1.55). Both are third-party listed the same way: Informed Choice lists both product lines. NSF Certified for Sport lists Gold Standard Double Rich Chocolate in the 10 lb tub only; the 5 lb tub we price is not on that list. Pick ISO100 if you want an all-isolate powder; pick Gold Standard if you want the lower cost per gram.
Informational comparison of label data, registry listings and cost, not medical advice.
The numbers, side by side
| Gold Standard 100% Whey | ISO100 | |
|---|---|---|
| Protein type | Blend: whey isolate, whey concentrate, hydrolyzed whey | Hydrolyzed whey isolate and whey isolate |
| Protein per scoop | 24 g (31 g scoop) | 25 g (32 g scoop) |
| Protein share of the scoop | 77% | 78% |
| Calories per scoop | 120 | 120 |
| Total fat | 1.5 g | 1 g |
| Total carbs | 3 g | 2 g |
| Total sugars | 1 g | 1 g |
| Servings in 5 lb | 74 | 71* |
| Sweeteners (this flavor) | Acesulfame potassium | Sucralose, stevia |
| NSF Certified for Sport | Not for the 5 lb tub. NSF lists Double Rich Chocolate in the 10 lb tub only | Not found |
| Informed Choice | Product line listed ("ON Gold Standard 100% Whey", no flavors) | Product line listed ("ISO100 Hydrolyzed Protein Powder (USA)", no flavors) |
| Price | $102.81 | $109.99 |
| Cost per scoop | $1.39 | about $1.55* |
| Cost per 25 g protein | $1.45 | about $1.55* |
| Buy | Check price → | Check price → |
* Dymatize does not print a servings count for the 5 lb tub, so we divided 5 lb (2,268 g) by the 32 g scoop, which makes ISO100’s cost per scoop and per 25 g approximate. Protein, scoop size, calories, fat, carbs, sugars and sweeteners are from each brand’s Nutrition Facts panel for the flavor priced. Informed Choice lists product lines, not flavors or pack sizes. NSF lists products by flavor and pack, and we count an NSF listing only when it covers the pack we link.
The real difference: isolate vs blend, then how each is listed
Whey isolate is whey that has been filtered further, so more of each gram is protein. ISO100 is made only from isolate; Gold Standard mixes isolate with whey concentrate. In these two products that shows up as a small difference in protein per scoop, 25 g against 24 g, rather than a large one. At the Amazon prices we recorded on September 30, 2026, the blend gives you more protein per dollar.
Both are third-party listed, and in the same program. Informed Choice lists both product lines, Gold Standard 100% Whey and ISO100 (USA), without flavors. According to Informed Choice, it tests products bought off the shelf for banned substances every month. NSF Certified for Sport lists Gold Standard Double Rich Chocolate and Vanilla Ice Cream in the 10 lb tub only; the 5 lb tub we price is not on that list. We did not find ISO100 in NSF Certified for Sport, NSF/ANSI 173 or Informed Sport. If you are a drug-tested athlete, check which program your sport accepts. See every listed powder in our third-party tested protein list.
ISO100’s closest rival: Gold Standard 100% Isolate
If you want an all-isolate powder from Optimum Nutrition, the like-for-like match for ISO100 is Gold Standard 100% Isolate. Like ISO100, it is hydrolyzed whey isolate and whey isolate, with 25 g of protein in a 31 g scoop. The Chocolate Bliss tub (about 3 lb, 44 servings) is $2.05 per 25 g of protein at the Amazon price we recorded. Like ISO100, it is in Informed Choice as a product line ("ON Gold Standard Isolate"), and we did not find it in NSF Certified for Sport, NSF/ANSI 173 or Informed Sport.
Gold Standard 100% Isolate · $2.05/25 g protein →
Who each one is for
Choose Gold Standard if you want the lower cost per gram of protein and you are fine with a whey blend. If you need NSF Certified for Sport, NSF lists only the 10 lb Double Rich Chocolate and Vanilla Ice Cream tubs, not the 5 lb tub linked here.
Choose ISO100 if you want an all-isolate powder with a little more protein per scoop. Its product line is listed in Informed Choice.
Frequently asked questions
Is Gold Standard or ISO100 better?
They are different kinds of whey. Gold Standard 100% Whey is a blend of whey isolate, whey concentrate and hydrolyzed whey; ISO100 is hydrolyzed whey isolate and whey isolate. ISO100 has a little more protein per scoop (25 g vs 24 g). Per 25 g of protein at the Amazon prices we recorded, Gold Standard costs less ($1.45 vs about $1.55). Both product lines are listed in Informed Choice. NSF Certified for Sport lists Gold Standard Double Rich Chocolate in the 10 lb tub only; the 5 lb tub we price is not on that list.
Which is cheaper per serving?
Per scoop, Gold Standard is $1.39 and ISO100 is about $1.55 for the 5 lb tubs. Because the scoops hold different amounts of protein, the fairer number is cost per 25 g of protein: $1.45 for Gold Standard and about $1.55 for ISO100.
What does each label say about lactose?
Neither label gives a lactose number, and neither says lactose-free. ISO100’s page says it is "filtered to remove excess lactose, carbs, fat, and sugar." Gold Standard’s label makes no lactose claim. Both list milk as an allergen.
Are they third-party tested?
Yes, both. Informed Choice lists both product lines, "ON Gold Standard 100% Whey" and "ISO100 Hydrolyzed Protein Powder (USA)", without flavors (list read September 22, 2026). According to Informed Choice, it tests products bought off the shelf for banned substances every month. NSF Certified for Sport lists Gold Standard Double Rich Chocolate and Vanilla Ice Cream in the 10 lb tub only; the 5 lb tub we price is not on that list. We did not find ISO100 in NSF Certified for Sport, NSF/ANSI 173 or Informed Sport.
What sweeteners do they use?
Gold Standard Double Rich Chocolate lists acesulfame potassium (some flavors also use sucralose). ISO100 Gourmet Chocolate lists sucralose and stevia. Sweeteners vary by flavor, so check the label of the flavor you buy.
Which tastes or mixes better?
We did not test taste or mixing. This page compares what the labels, the registries and the Amazon prices show.
Related
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Sources
- Optimum Nutrition Gold Standard 100% Whey, Double Rich Chocolate 5 lb Nutrition Facts and product page, optimumnutrition.com, read 2026-10-01.
- Dymatize ISO100 Gourmet Chocolate Nutrition Facts and product page, dymatize.com, read 2026-10-01.
- Optimum Nutrition Gold Standard 100% Isolate, Chocolate Bliss Nutrition Facts, optimumnutrition.com, read 2026-10-01.
- NSF Certified for Sport listing 1256427, "Gold Standard 100% Whey Double Rich Chocolate" (4.53 kg pack only), nsfsport.com, read 2026-10-01.
- Informed Choice certified products, choice.wetestyoutrust.com/certified-products, list read 2026-09-22.
- Amazon prices recorded 2026-09-30.
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