Walk into any supplement shop or browse any retailer's website and you will see two types of whey protein sitting next to each other: concentrate and isolate. The isolate is always more expensive. The question every buyer asks is whether the extra cost is actually worth it.
This article uses real UK price data from the WheyWise comparison table to answer that question with numbers, not marketing.
What is whey concentrate?
Whey concentrate is the least processed form of whey protein. After the liquid whey is separated from milk during cheese production, it is filtered and dried into a powder. The result is typically 70-80% protein by weight, with the remainder being naturally occurring fats, carbohydrates (mostly lactose), and minerals.
Concentrate is the most affordable type of protein powder available. It has a creamy taste and mixes well, which is why it remains the most popular choice for general fitness and muscle recovery. You can compare all whey concentrate prices on the dedicated comparison page.
What is whey isolate?
Whey isolate undergoes additional processing — typically microfiltration or ion exchange — to remove most of the fat and lactose. The result is a powder that is 90% or more protein by weight, with very little fat, carbohydrate, or lactose remaining.
This makes isolate the preferred choice for people who are lactose sensitive, those on a strict calorie budget, or anyone who wants the maximum amount of protein per scoop. See current whey isolate prices across UK retailers.
The real price difference in the UK
Based on current prices tracked across 85 UK retailers, the typical price difference between concentrate and isolate is 30-50% per 100g. However, this varies significantly by brand and retailer.
The cheapest whey concentrates start from around £0.48/100g, while the cheapest isolates start from around £0.90/100g. At the premium end, both types can cost £2.00+/100g from specialist brands.
The key insight: the price gap is smallest when you buy larger bags (2.5kg or 5kg) and during sales. During a MyProtein or Bulk sale, isolate prices can drop close to concentrate's normal price.
What you actually get for the premium
For every 100g of powder, isolate gives you approximately 90g of protein compared to concentrate's 75g. That is 20% more protein per gram of powder. When you factor in the price difference, isolate typically costs 10-30% more per gram of actual protein — not per gram of powder.
The other differences: isolate has roughly 1g of fat per 100g versus 5-7g in concentrate, and less than 1g of lactose versus 4-6g. If you are counting calories or avoiding lactose, these differences matter. If you are not, they are negligible.
Who should choose concentrate
- Budget-conscious buyers — concentrate offers the best protein per pound spent
- General fitness users who do not have specific macro targets
- People who tolerate lactose without issues
- Anyone buying in bulk (5kg bags of concentrate are the cheapest protein available)
Who should choose isolate
- People with mild lactose intolerance (severe intolerance may need a dairy-free option)
- Those on a calorie-restricted diet where every gram of fat matters
- Competitive athletes who need precise macro tracking
- Anyone who experiences bloating from concentrate
The verdict
For most people, whey concentrate is the smarter buy. The protein content difference is smaller than the price difference, and the extra fat and carbs are insignificant in the context of a balanced diet.
Isolate is worth the premium only if you have a specific reason to need it — lactose sensitivity, strict calorie counting, or a preference for a leaner product. If none of those apply, concentrate at half the price gives you 80% of the benefit.
The best way to decide is to compare the actual prices side by side — sort by Cost per 25g Protein and the answer becomes obvious for your budget. For today's best deals on both types, check the deals page.