Home / Whey protein (concentrate) / Amazon vs Prozis

Head to head · data from October 31, 2026

Amazon or Prozis for whey protein: which is better value per kg

The short answer. For whey protein, Amazon lists 44 products and Prozis another 22. By price per kg, Amazon’s median is €41.98/kg and Prozis’s is €55.12/kg. The highest scoring across both catalogues is Bulk Basic Proteína de Suero en Polvo | Vainilla | 1,25 kg | 41 Raciones | Hasta 18 g de Proteína | Bajo en Azúcar | Fórmula de Rápida Absorción | Apoya el Crecimiento y la Recuperación Muscular from Amazon, with 75 out of 100 at €21.24/kg. 1 products from Amazon and 0 from Prozis reach verification level 4.

Both stores measured on the same criterion: price per kg and certification verification level. There is no overall winner because there isn’t one: one can win on price and the other on certification, and here you see both separately.

† Some links are affiliate links — they do not change the ranking

Some store links are affiliate links: if you buy through them, this site may earn a commission at no extra cost to you. It changes nothing in the ranking: the score is computed beforehand and without reading those links, and products with no affiliate programme appear exactly the same. How it is calculated.

Both stores at a glance

Amazon

44 whey protein products

€41.98/kgmedian

From €21.24/kg to €79.17/kg. 1 at verification level 4 and 0 at level 3.

Prozis

22 whey protein products

€55.12/kgmedian

From €30.99/kg to €67.47/kg. 0 at verification level 4 and 0 at level 3.

Its best score: Prozis 100% Whey Prime 1000 g, 66/100 at €30.99/kg.

Amazon against Prozis, figure by figure

The same numbers for both

Amazon and Prozis for whey protein, with prices from October 31, 2026
Figure	Amazon	Prozis
Products compared	44	22
Median per kg	€41.98/kg	€55.12/kg
Cheapest per kg	€21.24/kg	€30.99/kg
Dearest per kg	€79.17/kg	€67.47/kg
Best score	75	66
Level 4 (certification backed by a third party)	1 of 44	0 of 22
Level 3 (the brand’s own lab report)	0 of 44	0 of 22

The median is not the price you will pay. It is the midpoint of that store’s catalogue in this category, and it tells you whether a store is dear or cheap overall. For buying, the specific row in the table below is what counts.

What each tub contains

Median dose per serving

Price per kilo does not tell you how much active ingredient is inside the kilo. This table does: for each ingredient, the median dose per serving at each store and how many products reach the dose backed by studies (the same reference this site scores with).

Ingredients and dose per serving at Amazon and Prozis, for whey protein
Ingredient	Amazon	Prozis
Whey protein concentrateEvidence-backed dose: from 20 g per serving	30.5 g44 of 44 contain it · 4 reach the dose	—22 of 22 contain it · none publishes the dose

The dose is per serving, not per tub. A big tub with a short dose forces you to take two scoops to get the same, and then it lasts half as long: that is why the price per dose in the next section does not match the price per kilo.

Why one is cheaper than the other

Factor by factor, with both stores’ data

Where the price difference between Amazon and Prozis for whey protein comes from
Factor	Amazon	Prozis
Cost of one effective dosePrice per kg and price per dose point to the same store, so the dose does not erase the label difference: Amazon is cheaper both ways.	€1.119	€1.470
Pack size (median)Amazon sells bigger packs, and a big pack spreads the same tub, the same label and the same shipping over more kilos. Part of the price gap per kg is this and not a discount: comparing one store’s small pack with the other’s large one inflates the gap.	1 kg	907 g
Different brands in the catalogueProzis mostly sells one brand, Prozis: 100 % of its catalogue in this category. Amazon spreads its own across 23 brands. A store selling its own brand skips the manufacturer’s margin and can cut the price without touching the formula; a reseller pays that margin and passes it on, and in exchange carries brands the other does not sell.	23 (23 % Desconocida)	1 (100 % Prozis)

None of these factors is an accusation. They are medians of what each store publishes on its pages on the day prices were collected: where a page does not declare a figure, that store does not count in that row instead of counting as a zero. A specific product can contradict its store’s median, and that is what the full table is for. How all of this is calculated.

All 66 products from both stores

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Products sorted by score (recommended)
#	Product	Store			Verification
01	Bulk Basic Proteína de Suero en Polvo · 1,25 kg	Amazonfree delivery from €35	€26.55	€21.24 /kg≈ €28.32 /kg of protein	No third-party seal	75
02	Crown Sport Nutrition Whey PROtein+ · Proteína de Suero de Leche (WPC) · 834 gVerified level 4	Amazonfree delivery	€39.99	€47.95 /kg≈ €63.93 /kg of protein	Verified	73
03	Whey Protein 1KG	Amazonfree delivery from €35	€23.43	€23.43 /kg≈ €31.24 /kg of protein	No third-party seal	72
04	Bulk Whey Proteína en Polvo, Banana, 2.5kg	Amazonfree delivery	€63.60	€25.44 /kg≈ €33.92 /kg of protein	No third-party seal	70
	Bulk Whey Proteína en Polvo, Vanilla, 1kg · 3 flavours	Amazonfree delivery from €35	€34.99	€34.99 /kg≈ €46.65 /kg of protein	No third-party seal	63
	Bulk Whey Proteína en Polvo, Banana, 500g	Amazonfree delivery from €35	€17.79	€35.58 /kg≈ €47.44 /kg of protein	No third-party seal	63
05	GymBeam True Whey Protein en polvo · 2,5 kg	Amazonfree delivery	€69.95	€27.98 /kg≈ €37.31 /kg of protein	No third-party seal	68
06	MASmusculo Whey FIT 1Kg · Proteína Whey en Polvo	Amazonfree delivery from €35	€27.99	€27.99 /kg≈ €37.32 /kg of protein	No third-party seal	68
07	GlobalNutricion Whey 80 Proteína en Polvo de Suero de Leche 1 kg Chocolate	Amazonfree delivery from €35	€29.90	€29.90 /kg≈ €39.87 /kg of protein	No third-party seal	67
08	Bulk Whey Proteína en Polvo, Unflavoured, 5kg	Amazonfree delivery	€149.99	€30.00 /kg≈ €40.00 /kg of protein	No third-party seal	66
	Bulk Whey Proteína en Polvo, Unflavoured, 500g · 3 flavours	Amazonfree delivery from €35	€19.99	€39.98 /kg≈ €53.31 /kg of protein	No third-party seal	61
09	Whey Protein 990 g para 1 mes. 24 g al día de Proteina de Suero	Amazonfree delivery from €35	€30.37	€30.68 /kg≈ €40.91 /kg of protein	No third-party seal	66
10	de proteinas de suero de leche sabor NEUTRO · 2 kg	Amazonfree delivery	€62.12	€31.06 /kg≈ €41.41 /kg of protein	No third-party seal	66
11	Prozis 100% Whey Prime 1000 g4.6 (1)	Prozisfree delivery	€30.99	€30.99 /kg≈ €41.32 /kg of protein	No third-party seal	66
	Prozis 100% Whey Prime 400 g · 2 flavours	Prozisfree delivery	€26.99	€67.47 /kg≈ €89.96 /kg of protein	No third-party seal	55
12	Premium Whey Protein · 2 kg	Amazonfree delivery	€63.00	€31.50 /kg≈ €42.00 /kg of protein	No third-party seal	65
13	Protein Works Whey Protein 360 · 600 g	Amazonfree delivery from €35	€19.45	€32.42 /kg≈ €43.23 /kg of protein	No third-party seal	65
14	Proteína de suero de leche en polvo Warrior Whey 500 g (hasta	Amazonfree delivery from €35	€16.38	€32.76 /kg≈ €43.68 /kg of protein	No third-party seal	65
15	Prozis Whey + Fibre 700 g	Prozisfree delivery from €24.99	€22.99	€32.84 /kg≈ €43.79 /kg of protein	No third-party seal	65
16	de proteinas de suero de leche · 2 kg	Amazonfree delivery	€71.30	€35.65 /kg≈ €47.53 /kg of protein	No third-party seal	63
17	Prozis Peanut Whey Protein 907g	Prozisfree delivery	€34.99	€38.58 /kg≈ €51.44 /kg of protein	No third-party seal	62
18	Prozis Whey Protein Fusion 900 g4.6 (1)	Prozisfree delivery	€34.99	€38.88 /kg≈ €51.84 /kg of protein	No third-party seal	62
	Prozis Whey Protein Fusion 700g	Prozisfree delivery	€34.99	€49.99 /kg≈ €66.65 /kg of protein	No third-party seal	58
19	Bulk Whey Proteína en Polvo, Chocolate & Mani, 500g	Amazonfree delivery from €35	€19.79	€39.58 /kg≈ €52.77 /kg of protein	No third-party seal	61
20	VITALDIN SPORT 100% Whey Protein Vainilla 500 g - 6,7g BCAA	Amazonfree delivery from €35	€19.90	€39.80 /kg≈ €53.07 /kg of protein	No third-party seal	61
21	de proteinas de suero de leche · 750 g	Amazonfree delivery from €35	€29.95	€39.93 /kg≈ €53.24 /kg of protein	No third-party seal	61
22	Premium Proteina Whey · 900 g	Amazonfree delivery	€35.95	€39.94 /kg≈ €53.25 /kg of protein	No third-party seal	61
23	IronMaxx 100% Proteína de suero en polvo - Yogur de Plátano bolsa de 500g	Amazonfree delivery from €35	€20.55	€41.10 /kg≈ €54.80 /kg of protein	No third-party seal	61
24	BIG Proteinas Whey · 2 kg	Amazonfree delivery	€82.50	€41.25 /kg≈ €55.00 /kg of protein	No third-party seal	61
25	iO.GENIX WHEY 80 PROFESSIONAL 2 KG	Amazonfree delivery	€83.95	€41.98 /kg≈ €55.97 /kg of protein	No third-party seal	60
	iO.GENIX WHEY 80 PROFESSIONAL 1 KG	Amazonfree delivery	€49.95	€49.95 /kg≈ €66.60 /kg of protein	No third-party seal	58
26	ProCell Proteína Whey 900g 100% Proteína de Suero Concentrada	Amazonfree delivery	€38.14	€42.38 /kg≈ €56.51 /kg of protein	No third-party seal	60
27	BioTechUSA 100% Pure Whey · 900 g	Amazonfree delivery	€38.90	€43.22 /kg≈ €57.63 /kg of protein	No third-party seal	60
28	Beverly WHEY · Concentrado Puro de Proteína de Suero Premim · 1 kg	Amazonfree delivery	€43.90	€43.90 /kg≈ €58.53 /kg of protein	No third-party seal	60
29	226ERS Whey Protein · 1 kg	Amazonfree delivery	€44.00	€44.00 /kg≈ €58.67 /kg of protein	No third-party seal	60
30	WFN Approved Whey Proteína en Polvo · 1 kg	Amazonfree delivery	€44.90	€44.90 /kg≈ €59.87 /kg of protein	No third-party seal	60
31	Life Pro Whey ProCao 2kg	Amazonfree delivery	€89.90	€44.95 /kg≈ €59.93 /kg of protein	No third-party seal	60
32	Prozis 100% Real Whey Protein 1000 g	Prozisfree delivery	€45.99	€45.99 /kg≈ €61.32 /kg of protein	No third-party seal	59
	Prozis 100% Real Whey Protein 2000g	Prozisfree delivery	€91.98	€45.99 /kg≈ €61.32 /kg of protein	No third-party seal	59
	Prozis 100% Real Whey Protein 907g	Prozisfree delivery	€49.99	€55.12 /kg≈ €73.49 /kg of protein	No third-party seal	57
	Prozis 100% Real Whey Protein 1814g	Prozisfree delivery	€99.98	€55.12 /kg≈ €73.49 /kg of protein	No third-party seal	57
	Prozis Natural Real Whey Protein 907g	Prozisfree delivery	€50.99	€56.22 /kg≈ €74.96 /kg of protein	No third-party seal	57
	Prozis Natural Real Whey Protein 1814g	Prozisfree delivery	€101.98	€56.22 /kg≈ €74.96 /kg of protein	No third-party seal	57
	Prozis 100% Real Whey Protein 400 g · 2 flavours	Prozisfree delivery	€24.99	€62.48 /kg≈ €83.29 /kg of protein	No third-party seal	56
33	Optimum Nutrition Standard 100% Whey Proteína en Polvo, 1.62 kg	Amazonfree delivery	€79.99	€49.38 /kg≈ €65.84 /kg of protein	No third-party seal	58
	Optimum Nutrition Standard 100% Whey Proteína en Polvo, 899g	Amazonfree delivery	€46.13	€51.31 /kg≈ €68.41 /kg of protein	No third-party seal	58
	Optimum Nutrition Standard 100% Whey Proteína en Polvo, 896g	Amazonfree delivery	€46.14	€51.50 /kg≈ €68.67 /kg of protein	No third-party seal	58
	Optimum Nutrition Standard 100% Whey Proteína en Polvo, 620g	Amazonfree delivery from €35	€34.99	€56.44 /kg≈ €75.25 /kg of protein	No third-party seal	57
	Optimum Nutrition Standard 100% Whey Proteína en Polvo, 300g	Amazonfree delivery from €35	€17.99	€59.97 /kg≈ €79.96 /kg of protein	No third-party seal	56
34	Prozis Real Whey + Hydro Collagen 907g	Prozisfree delivery	€44.99	€49.60 /kg≈ €66.13 /kg of protein	No third-party seal	58
35	Prozis Supreme Whey Protein 907g	Prozisfree delivery	€45.99	€50.71 /kg≈ €67.61 /kg of protein	No third-party seal	58
36	ESN Designer Whey Protein, Chocolate, 1 kg	Amazonfree delivery	€50.90	€50.90 /kg≈ €67.87 /kg of protein	No third-party seal	58
37	Prozis 100% Whey Prime + Creatine 907g	Prozisfree delivery	€47.99	€52.91 /kg≈ €70.55 /kg of protein	No third-party seal	57
38	Protein Works Whey Protein 360 · 600 g	Amazonfree delivery from €35	€32.41	€54.02 /kg≈ €72.03 /kg of protein	No third-party seal	57
39	Prozis Clear Whey + Collagen 600 g	Prozisfree delivery	€32.99	€54.98 /kg≈ €73.31 /kg of protein	No third-party seal	57
40	Proteína Whey Pura 100% Concentrada, 800g	Amazonfree delivery	€44.95	€56.19 /kg≈ €74.92 /kg of protein	No third-party seal	57
41	Prozis Zero Diet Whey 1500 g	Prozisfree delivery	€84.99	€56.66 /kg≈ €75.55 /kg of protein	No third-party seal	57
	Prozis Zero Diet Whey 750 g	Prozisfree delivery	€49.99	€66.65 /kg≈ €88.87 /kg of protein	No third-party seal	55
42	BioTechUSA Iso Whey Zero Natural · 908 g	Amazonfree delivery	€51.90	€57.16 /kg≈ €76.21 /kg of protein	No third-party seal	57
43	BioTechUSA 100% Pure Whey · 400 g · 2 flavours	Amazonfree delivery from €35	€22.90	€57.25 /kg≈ €76.33 /kg of protein	No third-party seal	57
44	Prozis Xtreme Whey Protein - Ultimate Series 1814g	Prozisfree delivery	€103.99	€57.33 /kg≈ €76.44 /kg of protein	No third-party seal	56
45	Prozis Whey Protein - Freakin Good 400 g	Prozisfree delivery from €24.99	€22.99	€57.48 /kg≈ €76.63 /kg of protein	No third-party seal	56
46	ORGAINIC Proteína de suero de leche ecológica · 1 kg	Amazonfree delivery	€58.90	€58.90 /kg≈ €78.53 /kg of protein	No third-party seal	56
47	Prozis Cacao Caliente con Proteína Whey 400 g · 3 flavours	Prozisfree delivery from €24.99	€23.99	€59.98 /kg≈ €79.96 /kg of protein	No third-party seal	56
48	AMIX Proteína Whey · 2 flavours	Amazonfree delivery	€63.90	€63.90 /kg≈ €85.20 /kg of protein	No third-party seal	55
49	BIG Only Whey Cacaolat Edición Especial 120g	Amazonfree delivery from €35	€9.50	€79.17 /kg≈ €105.56 /kg of protein	No third-party seal	53

66 products in this table

Questions about Amazon and Prozis for whey protein

Answered with the data on this page

Amazon or Prozis for whey protein?

On price per kg, Amazon: its median is €41.98/kg against €55.12/kg at Prozis, which is 31 % dearer. The median does not decide on its own: most of the rest of the mark is certification, and there Amazon has 1 products at level 4 and Prozis has 0.

Which is the cheapest whey protein across the two stores?

Why don’t Amazon and Prozis cost the same?

Prozis costs 31 % more per kg than Amazon (€55.12/kg against €41.98/kg, medians of both catalogues). That difference does not come out of nowhere. These are the data that explain it, with each store’s figure alongside: pack size (median), different brands in the catalogue. Price per kg and price per dose point to the same store, so the dose does not erase the label difference: Amazon is cheaper both ways. Amazon sells bigger packs, and a big pack spreads the same tub, the same label and the same shipping over more kilos. Part of the price gap per kg is this and not a discount: comparing one store’s small pack with the other’s large one inflates the gap.

Which of the two stores scores better?

Bulk Basic Proteína de Suero en Polvo | Vainilla | 1,25 kg | 41 Raciones | Hasta 18 g de Proteína | Bajo en Azúcar | Fórmula de Rápida Absorción | Apoya el Crecimiento y la Recuperación Muscular from Amazon, with 75 out of 100. The score is 35 % price per kg against the cheapest in the category, 35 % verifiable quality (certification, purity and additives), 20 % the category's own requirements and 10 % the buyers' rating at the store, and it is computed without looking at affiliate links. Prices from October 31, 2026.

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