Quick answer
Finding cheap protein powder in the UK is not about settling for the worst product on the shelf. It is about knowing where to look, what to compare, and which corners are safe to cut. The price difference between the cheapest and most expensive protein per serving can be 5x or more, and the expensive option is not always better. This guide breaks down the most affordable protein powder options available in the UK right now, using live price data from 85+ retailers. Every recommendation is based on cost per 25g of protein, the only metric that gives a fair comparison across different bag sizes and brands. For the live, always current ranking, see our cheapest protein powder comparison, which re-sorts every time prices change.
Cheapest protein powder by type (2026)
The cheapest pick in each category right now, ranked by cost per 25g of protein. We re-check prices across 85+ UK retailers every week, so use the live links for today's exact figure.
| Protein type | Cheapest picks | From / 25g protein | Live prices |
|---|---|---|---|
| Whey concentrate | Myprotein Impact Whey, Bulk Pure Whey | ~30p | Compare |
| Whey isolate | Bulk Pure Whey Isolate, Myprotein Impact Isolate | ~40p | Compare |
| Vegan | Bulk Vegan Protein, Myprotein Pea Protein | ~40p | Compare |
| Clear whey | Bulk Clear Whey, Myprotein Clear Whey | ~55p | Compare |
What makes protein powder cheap or expensive?
The price of protein powder comes down to four things: protein type, bag size, brand, and whether there is a sale on. Understanding these factors lets you find genuinely cheap protein without accidentally buying something poor quality.
- 1
Protein type. Whey concentrate is the cheapest. Isolate costs 20 to 40 percent more. Casein and clear whey cost more again. Vegan blends sit somewhere in between.
- 2
Bag size. Buying 2.5kg or 5kg bags almost always gives a lower cost per serving than 1kg bags. The upfront cost is higher but the per-gram value is significantly better.
- 3
Brand. Direct-to-consumer brands like Myprotein and Bulk are consistently cheaper than brands sold through third-party retailers, since there is no middleman margin.
- 4
Sales and codes. Myprotein runs near-constant discount codes. Bulk has more stable pricing but occasionally runs 20 to 30 percent off sales. Timing your purchase around these can save 10 to 25 percent.
Cheapest whey concentrate: the budget king
If pure value is your priority, whey concentrate is where to start. It delivers 70 to 80 percent protein per 100g at the lowest cost per serving of any protein type. The two cheapest options in the UK are consistently Myprotein Impact Whey and Bulk Pure Whey Protein, both in 2.5kg or 5kg bags.
At current prices, whey concentrate can be found for under £1.50 per 100g from the cheapest retailers. That works out to roughly 30 to 40p per 25g serving of protein. Check the whey concentrate price comparison for today's exact prices.
Community perspective
What others are saying
Just to throw into the mix; if you’re buying whey protein (and not a bulk powder etc), then aim for 80g protein per 100g as a min (it’ll say this in the nutrition). If it’s just whey, and it’s less than this, then it’s poor quality and padded out. Some of the really cheap ones are cheap for a reason, make sure you’re comparing apples with apples.
u/MrJoell in r/UKFrugal
Sign up to My Protein emails. They do have sales quite frequently and you'll get emails with details. Also, download their app for more exclusive deals. Try shops like Home Bargains and B&M. They have much cheaper protein than big brands.
u/LordOfTheIron in r/UKFrugal
Costco seem to have the cheapest brand protein so far from a well known brand where you don’t have to worry about the quality too much, in store at Costco u can 2.5kg whey protein for £35.98, if anyone has seen cheaper they can correct me but this seems to be the best deal so far on whey protein from a respected brand.
u/harryebh in r/UKFrugal
Anecdotes are useful for spotting recurring taste, texture and convenience issues, but they are not evidence of effectiveness.
Cheap whey isolate: more protein, still affordable
Whey isolate delivers 85 to 92 percent protein per 100g with less fat and lactose. It costs more than concentrate but is worth considering if you are lactose sensitive or want more protein per scoop. The cheapest isolates in the UK typically come from Bulk and Myprotein.
Browse the cheapest whey isolate prices to see how isolate compares on a per-serving basis. For a detailed breakdown of whether the premium is worth it, read whey isolate vs concentrate.
Cheapest Whey Protein
Sports Fuel Premium Protein
Bodybuilding Warehouse · 5kg
Budget vegan protein
Vegan protein has come down in price significantly over the past two years. Bulk's Vegan Protein Powder and Myprotein's Pea Protein Isolate are among the most affordable plant-based options. Look for blends of pea and rice protein, which offer a more complete amino acid profile than single-source options.
Compare all options on the vegan protein price comparison.
Clear whey on a budget
Clear whey is the fastest-growing category in UK protein, but it tends to cost more per serving than standard whey. If you want the juice-style experience without overpaying, compare prices carefully, since the spread between cheapest and most expensive clear whey is significant. See the cheapest clear whey protein for current prices.
Five ways to pay less for protein powder
- 1
Buy bigger bags. 2.5kg and 5kg bags are almost always cheaper per serving than 1kg. The savings typically range from 15 to 30 percent.
- 2
Use discount codes. Check the protein powder deals and discount codes before buying. Stacking a code on a sale price is the fastest way to cut costs.
- 3
Compare per 25g of protein, not per bag. A £40 bag can be cheaper per serving than a £25 bag. The cheapest protein powder ranking does this calculation automatically.
- 4
Stick to unflavoured or basic flavours. Chocolate and vanilla are usually the cheapest flavours since they sell in the highest volume. Specialty flavours often cost more.
- 5
Consider less popular brands. Applied Nutrition, Protein Works and Warrior often undercut the big two on specific products. Check alternatives to Myprotein for options beyond the obvious choices.
What to avoid when buying cheap protein
Not every cheap protein powder is a good deal. Watch out for these.
- 1
Very low protein per 100g. If a product has under 60g of protein per 100g, you are paying mostly for filler. Check the nutrition label.
- 2
Brands with no reviews or lab testing. Stick to established UK brands unless you can verify the protein content independently.
- 3
Close-to-expiry stock. Some deals are cheap because the product expires soon. Check the best-before date.
- 4
Proprietary blends. If the label does not state exactly how much whey protein is in each serving, be cautious about the actual protein quality.
The bottom line
The cheapest protein powder in the UK is almost always whey concentrate from a direct-to-consumer brand, bought in a large bag during a sale with a discount code. That combination can get protein for under 30p per 25g serving.
But the cheapest option changes weekly. Use the protein powder price comparison to see what is cheapest right now, since prices are checked across 85+ UK retailers every week.
Frequently asked questions
What is the cheapest protein powder in the UK?+
Whey concentrate from a direct-to-consumer brand such as Myprotein or Bulk, bought in a 2.5kg or 5kg bag. During a sale this works out at roughly 30p per 25g serving of protein, the lowest cost of any protein type.
Is cheap whey protein worse quality?+
Not necessarily. Cheap whey concentrate from established UK brands is typically 70-80% protein per 100g, the same core ingredient as pricier options. Avoid anything under 60g protein per 100g or with unclear proprietary blends.
How much should whey protein cost per kg in the UK?+
Budget whey concentrate is often under £1.50 per 100g, roughly £15 per kg, and less during sales. Larger 2.5kg or 5kg bags are almost always cheaper per serving than 1kg tubs.
Is Myprotein or Bulk cheaper?+
It varies weekly. Bulk has lower, more stable everyday prices, while Myprotein is often cheaper during its frequent code sales. The ProteinDeals cheapest ranking compares both live across 85+ retailers so you can see which is cheaper today.