Bulk Pure Whey Isolate
Buy this instead of Pure Whey Protein if concentrate sits heavy on you, not because 81g per 100g beats 71g on a spreadsheet.
- Lean macros
- Low lactose
- 81g
- Protein / 100g
- 24g
- Per 30g scoop
- £1.05
- Per 25g protein
- £169.99
- 5.00kg pack
How the numbers stack up against the price
£1.05 buys 25g of protein here, which makes it the 15th cheapest of the 24 powders we have reviewed, behind USN Blue Lab Whey at 100p, and 11p over the median.
Practically, the difference in a 30g scoop is 24g of protein against 23g, so you are paying for what is stripped out rather than what is added: sugar drops from 12g per 100g to 1.4g and fat from 3.5g to 1g. That matters mid-cut and it matters if dairy makes you bloat. Two warnings before you order. Bulk sells a second, stevia-sweetened isolate called Natural Pure Whey Isolate, and they are not the same tub. And flavour quality here is a lottery, so take the 500g bag on a new flavour rather than committing to 2.5kg.
Cost per 25g of protein, across our 24 reviews
Median 94p
- Protein Works Vegan Pea Protein - BLACK Innovation39p
- Protein Works Vegan Protein 360 - GOLD Innovation44p
- Protein Works Vegan Protein 360 - PLATINUM Innovation54p
- Bulk Pure Whey Protein70p
- Protein Works Whey Protein 360 - PLATINUM Innovation71p
- Protein Works Whey Protein 360 - GOLD Innovation72p
- PhD Nutrition Diet Whey73p
- NXT Nutrition Beef Protein Isolate74p
- Protein Works 100% Micellar Casein - BLACK Innovation82p
- PER4M Nutrition Whey Protein85p
- PER4M Nutrition Isolate Zero86p
- MyProtein Impact Diet Whey92p
- MyProtein Clear Whey Protein96p
- USN Blue Lab Whey100p
- Bulk Pure Whey Isolate£1.05
- MyProtein Impact Whey Protein£1.09
- MyProtein Impact Whey Isolate£1.22
- Applied Nutrition ISO XP£1.24
- Applied Nutrition Critical Whey£1.25
- Warrior Whey£1.26
- Bulk Clear Whey Isolate£1.33
- Protein Works Clear Diet Whey Protein - GOLD Innovation£1.37
- Scitec Nutrition 100% Whey Protein Professional£1.49
- Protein Works Diet Whey Protein Isolate - BLACK Innovation£1.56
Cheapest in-stock listing at a partner retailer, for packs of 400g and over.
A single isolate, filtered further than the concentrate, so lactose drops from around 12g per 100g to 1.4g. That is the whole reason to pay the difference: it is the version you can drink straight after a session without it sitting on you.
What the label gets right, and wrong
Strengths
- Only 1.4g of sugar and 1g of fat per 100g, so it costs you almost nothing outside the protein
- Buyers repeatedly describe it as easier on the stomach than the concentrate
- Sunflower lecithin, no soy
- Same 500g to 5kg size ladder as the concentrate, so you can trial before committing
Watch-outs
- The page headline says 26g and the label says 24g in a 30g scoop. Plan on 24g
- Flavour is inconsistent between lines, and the malted chocolate variants attract specific, repeated criticism
- Easy to confuse with Natural Pure Whey Isolate, which is a different product sweetened with stevia
- Buyers report receiving Pure Whey Protein when they ordered the isolate, so check the bag before you open it
Where to buy it
Ordered by cost per 25g of protein, because pack sizes and protein densities differ enough that a headline price on its own does not tell you which is better value.
| Retailer | Size | Price | Per 25g | Go to retailer |
|---|---|---|---|---|
| Bulk | 5000g | £169.99 | £1.05 | View deal ↗ |
| Amazon UK | 1000g | £43.72 | £1.35 | View deal ↗ |
2 partner retailers stock a 400g or larger pack of this product.
Price history
What a scoop actually contains
Taken from the manufacturer’s published label. Source.
Bulk titles the page "26g Whey Protein Isolate" but the panel it publishes reads 24g in a 30g scoop, because the flavoured tub carries cocoa and flavouring that the marketing figure does not. 24g is the number to plan your day around.
| Nutrient | Per 100g | Per 30g |
|---|---|---|
| Protein | 81g | 24.3g |
| Energy | 360 kcal | 108 kcal |
| Carbohydrate | 5g | 1.5g |
| of which sugars | 1.4g | 0.4g |
| Fat | 1g | 0.3g |
| of which saturates | 0.5g | 0.1g |
| Fibre | 3.4g | 1.0g |
| Salt | 0.62g | 0.2g |
Ingredients and formulation
Protein sources, in label order
- 01Whey protein isolate (milk)
Sweeteners and emulsifier
Sucralose
Sunflower lecithin
Pack sizes
500g · 1kg · 2.5kg · 5kg
Flavour quality is the least consistent thing about this product. Vanilla and strawberry get praised; the chocolate malted honeycomb line gets taken apart by name in more than one review below.
Third-party testing
Certification is per programme and often per flavour or per batch, so a badge on one product does not carry across a brand’s whole range.
As with Pure Whey Protein, Bulk keeps batch testing in its separately sold Informed range. Nothing on this product page claims third-party testing.
Made by
Sports Supplements Limited, trading as Bulk, Colchester, Essex
Taste and what buyers report
Quoted and linked, so you can read the full thread.
“The Whey Isolate offers a big, clean protein bang for your buck.”
“Bulk protein is pretty good specially the isolate as it is lighter on tummy.”
“Chocolate malted honeycomb whey isolate tastes genuinely awful.”
“On last order I got a vanilla tasting whey protein isolate, but the bag says salted caramel.”
“I ordered the Whey Isolate and received Pure whey protein.”
What the maker does not publish
- Bulk publishes the chocolate panel only. The unflavoured tub is sold under the same name and will be higher in protein per 100g, but Bulk does not publish a separate figure for it.
- The gap between the "26g" in the page title and the 24g on the panel is not explained anywhere on the product page.
Questions buyers ask
The things people search for about Bulk Pure Whey Isolate, answered from the label and the live partner prices rather than from the brand’s own copy.
How much protein is in Bulk Pure Whey Isolate?
81g per 100g on the flavoured tub, which is 24g in a 30g scoop. Bulk markets it as 26g per serving; the published panel says 24g, and that is the figure to plan around.
What is the difference between Bulk Pure Whey Isolate and Natural Pure Whey Isolate?
They are two products. Pure Whey Isolate is sweetened with sucralose. Natural Pure Whey Isolate is sweetened with steviol glycosides and uses natural flavouring, which testers describe as noticeably sweeter and more divisive. Check which one is in your basket.
Is Bulk Pure Whey Isolate worth it over Pure Whey Protein?
Only for a reason. A 30g scoop gives 24g of protein against 23g from a 32g scoop of the concentrate, so the protein difference is small. What you are buying is 1.4g of sugar instead of 12g and 1g of fat instead of 3.5g. If concentrate makes you bloat, or you are cutting and counting every gram, it earns the premium. Otherwise it does not.
Is it good for lactose intolerance?
It is lower in lactose than the concentrate by a long way, at 1.4g of sugar per 100g against 12g, and buyers do report it being easier on the stomach. It is still a milk product and it is not lactose free.
Reviewed next to
Bulk
Pure Whey Protein
Bulk's other option, on a different protein base.
70p / 25g protein
MyProtein
Impact Whey Isolate
The same job from MyProtein, at a different price point.
£1.22 / 25g protein
Applied Nutrition
ISO XP
90g protein per 100g against 81g here, if density is what you are after.
£1.24 / 25g protein
Not sure this is the one?
Answer five questions and the Protein Finder narrows the whole range down to what fits your goal, budget and diet.
Last updated 8 September 2026