The UK protein powder market is enormous — hundreds of products, dozens of retailers, and prices that change weekly. This guide cuts through the noise. I've compared the most popular options on price per 100g, protein content, and availability across major UK retailers.
One note before we start: this isn't a taste test or a lab analysis — it's a price and value comparison. For what it's worth, I've tried most of these personally, but your palate is different to mine.
Best overall value: MyProtein Impact Whey
MyProtein Impact Whey consistently comes out cheapest per 100g, especially during their frequent sales (which is most of the time, honestly). At roughly £1.40–1.60/100g on sale, it's hard to beat. The protein content is solid at around 82g per 100g, and there are dozens of flavours.
The main downside is that the "real" price versus sale price is a bit of a game — the listed price is inflated so the constant discount looks bigger. Use the per-100g price as your benchmark, not the percentage off.
Best runner-up: Bulk Pure Whey Protein
Bulk is MyProtein's closest competitor on price. Their Pure Whey Protein sits at around £1.50/100g and the quality is comparable. Some people prefer the taste of Bulk's flavours — particularly the vanilla, which is less artificial-tasting than MyProtein's.
Bulk also runs regular sales and has a good selection of sizes from 500g up to 5kg.
Best isolate: MyProtein Impact Whey Isolate
If you're lactose intolerant or want a cleaner macro profile, whey isolate is worth the premium. MyProtein's isolate sits at around £2.50–3.00/100g, which is roughly double the concentrate — but the protein content is higher (around 90g/100g) and it's lower in fat and carbs.
Best premium option: Optimum Nutrition Gold Standard
ON Gold Standard is the global benchmark for a reason. It's not cheap — typically £2.20–2.50/100g — but the consistency and quality are excellent. If you buy via Holland & Barrett during a 3-for-2 or buy-one-get-one event, the effective price becomes much more competitive.
Best budget pick: Protein Works Whey Concentrate 80
Protein Works often flies under the radar but their whey concentrate regularly comes in under £1.60/100g on sale with a discount code. The flavour selection is decent and the quality is consistent.
How to actually compare
Don't compare total prices — compare price per 100g. A 2.5kg bag looks expensive next to a 1kg bag, but it's almost always cheaper per gram. Use the comparison table to see current prices across all retailers sorted by per-100g cost.
Also factor in any active discount codes — a 25% off code can make a seemingly expensive retailer the cheapest option overnight. Check the deals page for today's best offers, or read MyProtein vs Bulk: which is cheaper? for a head-to-head breakdown.