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Cheapest overallMatrix Nutrition
Micellar Casein Protein Powder66 bought this week
66bought this week68.2% protein · 20.5g / 25g serving
Bag · 4kg
£49.99
£0.46 / 25g protein
Casein
Cheapest Casein Protein UK
Compare protein prices from MyProtein, Bulk, Optimum Nutrition and 85+ other UK retailers. Every product ranked by cost per 25g of protein. Free, updated weekly. Whether you are buying whey concentrate, whey isolate, vegan protein, casein, or a mass gainer, every bag is normalised to the same metric so you can compare across brands, sizes, and protein percentages without doing the maths yourself. No sponsored rows, no affiliate-biased rankings. The cheapest option sits at the top because it is the cheapest, not because a brand paid for placement.
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Hand-picked by our nutrition team every Monday, 07:00. Scored on £/25g protein, clean-label, and weekly velocity.
Showing 17 casein products
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About Casein Protein
Casein is a slow-digesting protein derived from milk, making it ideal for overnight recovery or as a between-meals protein source. It forms a gel in the stomach, providing a sustained release of amino acids over several hours — which is why many athletes take it before bed.
Compare every casein protein product available from UK retailers below, sorted by price per 100g. Casein typically costs more than whey concentrate but serves a different purpose in your nutrition plan.
If you are looking for a fast-absorbing post-workout option instead, whey concentrate or whey isolate would be more appropriate. For a plant-based slow-release alternative, look for casein-like blends in our vegan section.
Methodology
How we rank every bag.
Independent, transparent, and updated weekly. Here's what goes into each score.
01
Cost normalised to £/25g
Every bag divided by its true protein weight, so you see the real cost of a scoop across any size or brand.
02
Protein quality, not just %
Protein %, leucine and digestibility feed the Performance score. A 90% isolate and a 90% vegan blend are not the same.
03
Clean-label audit
Ingredient count, artificial sweeteners, added sugars, third-party certifications. 0 to 100 score.
04
Social and review signals
Weekly purchase volume and weighted review scores surface what people actually re-buy, not just what ranks on search.
Questions, answered.
Casein is most commonly taken before bed because it digests slowly over 6-8 hours, providing a sustained release of amino acids during sleep. It can also be used as a meal replacement or between meals.