If you're buying protein powder in the UK and want to spend as little as possible, you'll inevitably end up choosing between MyProtein and Bulk. They dominate the budget end of the market, they both run near-constant sales, and they're both genuinely decent quality.
Here's how they actually compare.
Price per 100g
On a like-for-like basis (standard whey concentrate, 2kg+ bag, during a sale), MyProtein and Bulk are very close. MyProtein edges ahead slightly on the best sale prices — their headline discount events can push Impact Whey below £1.40/100g, whereas Bulk's floor is around £1.45–1.50/100g.
Outside of sale periods, Bulk's pricing is more stable and honest. MyProtein's "normal" prices are inflated to make the perpetual sale prices look bigger. This makes it hard to know if you're getting a good deal unless you track prices over time.
Protein content
Both are comparable: MyProtein Impact Whey is around 82g protein per 100g, Bulk Pure Whey is around 80g. The difference is negligible in practice.
Flavours
MyProtein wins on variety — they have a huge number of flavours, including some unusual ones. Bulk's range is smaller but many people find their flavours less artificial-tasting. The vanilla and chocolate naturals are commonly cited as better than MyProtein's equivalent.
Discount codes
Both retailers regularly offer discount codes. MyProtein codes are easier to find — there's nearly always a code active somewhere. Bulk's codes are slightly less frequent but their base prices are more consistent.
WheyWise tracks active codes for both — check the protein powder price comparison to see the effective post-code price for each product.
MyProtein Impact Whey Protein Powder
810g bag
UK's bestselling whey concentrate with 82g protein per 100g. Regularly discounted 40-60% — never pay full price.
See cheapest price →Buy direct from MyProtein →MyProtein Impact Whey Protein Powder
810g bag
UK's bestselling whey concentrate with 82g protein per 100g. Regularly discounted 40-60% — never pay full price.
See cheapest price →Buy direct from MyProtein →Quick verdict
Pros
- + 82g protein per 100g high purity
- + Cheapest per serving during sales
- + Huge 60+ flavour range
- + 5kg bags for long-term savings
Cons
- – Full price is poor value
- – Needs discount code to compete
- – Reformulations change taste occasionally
Quick verdict
Pros
- + 82g protein per 100g high purity
- + Cheapest per serving during sales
- + Huge 60+ flavour range
- + 5kg bags for long-term savings
Cons
- – Full price is poor value
- – Needs discount code to compete
- – Reformulations change taste occasionally
Bulk Pure Whey Protein
2.5kg bag
Budget-friendly Informed Sport tested whey from Bulk with 50+ flavours. Consistently among the cheapest per serving in the UK.
See cheapest price →Buy direct from Bulk →Bulk Pure Whey Protein
2.5kg bag
Budget-friendly Informed Sport tested whey from Bulk with 50+ flavours. Consistently among the cheapest per serving in the UK.
See cheapest price →Buy direct from Bulk →Quick verdict
Pros
- + Among cheapest UK whey options
- + Huge 50+ flavour range
- + 22g protein per 30g scoop
- + Informed Sport batch tested
Cons
- – 70-75% protein purity only
- – Some flavours overly artificial
- – Can cause bloating if lactose-sensitive
Quick verdict
Pros
- + Among cheapest UK whey options
- + Huge 50+ flavour range
- + 22g protein per 30g scoop
- + Informed Sport batch tested
Cons
- – 70-75% protein purity only
- – Some flavours overly artificial
- – Can cause bloating if lactose-sensitive
Which should you buy?
Honestly, check both. The cheapest on any given day depends on what sales and codes are active. The live comparison table shows current prices for both — sort by price per 100g and buy whichever is cheaper today. That's the only answer that's consistently correct. For the overall cheapest protein powder in the UK, including brands beyond these two, see the full ranking.
For a deeper look at how these brands compare on cost per gram of actual protein, see cheapest protein per gram UK. For today's active discounts on both brands, check the deals page.
