If you want a pure isolate for the least money per serve, R1 Protein WPI 5 lb wins. Dymatize ISO100 has the fewest carbs and blends hydrolysed whey isolate with regular whey isolate, but costs more. ON Gold Standard 100% Whey costs the least per serve of the three, but it is a whey blend with isolate as the main ingredient, not a pure isolate. Here is the full comparison.
Side-by-side comparison
| Dymatize ISO100 | R1 Protein WPI | ON Gold Standard Whey | |
|---|---|---|---|
| Protein per scoop | 25 g (32 g scoop) | 25 g (32 g scoop) | 24 g (30.4 g scoop) |
| Protein source | Hydrolysed whey isolate and whey isolate | Whey isolate and hydrolysed isolate | Whey isolate (main), concentrate |
| Carbs / fat per scoop | 2 g / 1 g (Gourmet Chocolate) | 3 g / 0.5 g (Chocolate Fudge) | 3 g / 1 g (Double Rich Chocolate) |
| Sugars | 1 g | 0 g | 1 g |
| Testing (as stated by brand) | Banned substance tested | Informed Choice | Informed Choice |
| 5 lb price | $299.95 | $249.95 | $219.95 |
| 5 lb serves | 71 | About 71 | 74 |
| Cost per serve (5 lb) | $4.22 | $3.52 | $2.97 |
Cost per serve is based on the serve sizes and tub weights on each label. Figures differ a little between flavours.
Dymatize ISO100: fewest carbs
ISO100 is built entirely from isolate and hydrolysed isolate. Each scoop gives 25 g of protein, 2 g of carbohydrate and 1 g of fat, with 2,677 mg of leucine. It is the priciest per serve here, but suits people who want a very lean shake and like its dessert flavours such as Fruity Pebbles and Cocoa Pebbles. The 3 lb tub in Gourmet Vanilla and Gourmet Chocolate is $179.95. Read our full ISO100 guide for every flavour.
R1 Protein WPI: best-value pure isolate
R1 Protein uses only isolate and hydrolysed isolate, with no concentrate, creamers or gums. You get 25 g of protein, 0 g sugars and 0.5 g of fat per scoop of Chocolate Fudge, and the 5 lb tub is $249.95. It also has one of the biggest flavour ranges we stock.
ON Gold Standard: best value per serve
Gold Standard lists whey isolate first but also contains concentrate, so it has a little more lactose. At $2.97 a serve in the 5 lb tub, it is the budget pick for anyone who handles dairy well. Read our full Gold Standard review.
Which should you buy?
- Best value overall: ON Gold Standard 100% Whey 5 lb.
- Best-value pure isolate: R1 Protein WPI 5 lb.
- Fewest carbs: Dymatize ISO100.
- Least fat and sugar: R1 Protein WPI.
- Sensitive stomach: either isolate, ISO100 or R1 WPI, rather than a blend. Isolate is lower in lactose but not lactose free.
All three give enough protein per scoop to help you reach the ISSN's suggested 1.4 to 2.0 g per kg of body weight a day. Total daily protein matters far more than which tub you pick. Compare more in our best WPI guide.
Shop the products in this guide
Dymatize ISO100 5 lb
R1 Protein WPI 5 lb
ON Gold Standard Whey 5 lbBrowse all whey protein isolates and hydrolysed whey.
FAQs
Is ISO100 better than Gold Standard?
ISO100 is a pure isolate with slightly fewer carbs (2 g against 3 g) and the same 1 g of fat, while Gold Standard is a blend led by isolate. ISO100 suits people who want a very lean shake or are sensitive to lactose. Gold Standard is about $1.25 cheaper per serve in the 5 lb size, so it is better value if dairy is not an issue.
Which whey isolate is best value in Australia?
Of these three, R1 Protein WPI 5 lb is the best-value pure isolate at about $3.52 per serve at today's price. Prices change often, so compare the cost per serve rather than the tub price.
Is hydrolysed whey worth paying more for?
For most people, no. Hydrolysed whey is partly broken down, but for building muscle the total protein you eat each day matters most. Pay extra only if you prefer the taste, mixability or how it sits in your stomach.
Are these proteins tested for banned substances?
According to the brands, R1 Protein and ON Gold Standard are Informed Choice certified, and Dymatize states ISO100 is banned substance tested. If you are a drug-tested athlete, check the current certification for your exact batch before use.
Sources: ISSN protein position stand (2017); product labels and brand nutrition panels, checked October 2026.
Order online with Australia-wide delivery, free on orders of $99.99 or more, or visit a Supps247 store in Melbourne, regional Victoria or Brisbane to compare products in person. Members can use our member price match on full-priced items.
Prices and stock were checked on 22 October 2026 and can change at any time. Always read the label and follow the directions for use. If you have a medical condition, are pregnant or take regular medication, check with your doctor first.
