Is PhD Protein Expensive? What Diet Whey Really Costs Per 25g of Protein

Diet Whey, 2kg

£1.17Diet Whey, 2kgPer 25g of protein

Diet Whey, 1kg

£1.37Diet Whey, 1kgPer 25g of protein

Protein per 100g

64gProtein per 100gAgainst 71g to 80g for most wheys

PhD's best-known powder, Diet Whey, cost £34.99 for 1kg and £59.99 for 2kg on PhD's own site in October 2026, with no sale running. Converted to protein, that is £1.37 and £1.17 per 25g. Plain PhD Whey came to about £1.20 per 25g in a 1kg bag, and PhD's Diet Plant protein was cheapest of the range at about £0.99.

Against the mainstream wheys in our catalogue, which cost about £0.99 to £1.21 per 25g of protein, Diet Whey sits at the dearer end. Prices change, so check the live PhD Diet Whey prices before buying.

Diet Whey is not just whey. Its protein blend, whey concentrate with soya isolate and milk protein, makes up about 75% of the powder. The rest is waxy barley flour, flaxseed, gums, and a set of diet extras: conjugated linoleic acid (CLA), acetyl-L-carnitine and green tea extract.

That leaves 64g of protein per 100g, compared with 71g to 80g for most plain wheys, so you pay for more powder to get the same protein. Whether the extras are worth it is your call, but they are not protein, and they are the main reason the price per 25g is higher.

If you just want protein at the lowest price, a plain whey such as Bulk Pure Whey or The Protein Works Whey Protein 80 will usually cost less. Plain PhD Whey is the closer like-for-like if you want to stay with the brand.

1. 1

   You want a more filling shake. Diet Whey's barley flour and flaxseed add carbohydrate and fibre, which suits a snack-style shake better than a plain whey.

2. 2

   You buy the 2kg bag or catch a promotion. At £1.17 per 25g, the big bag is close to Myprotein's price; a sale can bring it below.

3. 3

   You want plant protein. PhD Diet Plant was the cheapest PhD powder per 25g of protein in our data, at about the same price as Bulk Pure Whey.