ABCDEFGHIJKLMNOPQRSTUVWXYZAA
1
UK protein powders — measured protein vs label claim
2
Seven products, one sealed batch each, tested Jun–Jul 2026. Protein measured two ways: Dumas nitrogen x 6.25 (the legal method) and amino acid summation (true protein). All figures per 100 g of powder.
3
4
BrandProduct / batchTypePROTEIN BY
NITROGEN
(Dumas)		vs labelPROTEIN BY
AMINO ACIDS
((Lab 1))		vs labelPROTEIN BY
AMINO ACIDS
(Lab 2		vs labelAverage Amino
Acid Result		2nd lab batch
SAME or
DIFFERENT?		Label protein
g/100g
5
 WHEY PROTEINS
6
Optimum NutritionGold Standard 100% Whey - Vanilla Ice Cream
batch 1382639		Whey79.230.3%77.64-1.7%——not retested79.00
7
Protein WorksWhey Protein 80 - Banana Smooth
batch 050226135510		Whey75.191.6%68.08-8.0%——not retested74.00
8
MyProteinImpact Whey Protein - Vanilla
batch W609310217		Whey72.761.1%68.67-4.6%——not retested72.00
9
Applied NutritionCritical Whey - Chocolate Milkshake
batch L26123		Whey blend + MPC68.31-5.1%63.83-11.4%68.18-5.3%-8.3%SAME batch
L26123		72.00
10
BulkPure Whey Protein - Vanilla
batch 5550000056701		Whey63.91-10.0%60.49-14.8%63.53-10.5%-12.7%71.00
11
NON-WHEY — different category, judged separately
12
Serious ProteinChocolate Protein Powder
batch L260546967		Soy + milk blend69.56-14.0%59.28-26.7%63.72-21.2%-23.9%DIFFERENT batch
L260547349		80.86
13
Free SoulVegan Protein Blend - Chocolate
batch 25282		Pea + hemp vegan58.41-11.5%46.52-29.5%48.73-26.2%-27.8%SAME batch
25282		66.00
14
Whey average71.88-2.4%67.74-8.1%-7.9%73.60
15
16
• SAME batch = the second lab tested the identical batch as the main round, so the two results are a true inter-lab confirmation.
17
• DIFFERENT batch = the second lab tested a different batch of the same product. Consistent results across two batches, but NOT inter-lab confirmation of a single sample. Do not describe these as replicates.
18
• Alta retested only the four products that came in below their declared figure on the Dumas method. Optimum Nutrition, Protein Works and MyProtein met or beat their claim and were not retested.
19
• vs label = (measured - declared) / declared. Negative means the product contains less than the pack states.
20
• Unexplained nitrogen gap: nitrogen the Dumas test counted as protein that the amino acid analysis cannot account for. A gap of 1.5-4 g is normal (unmeasured tryptophan, incomplete cystine recovery). Larger gaps indicate non-protein nitrogen.
21
• UK/EU labelling tolerance for protein is +/-20%. Every product here is inside that tolerance on the Dumas method, i.e. legally compliant.
22
• Alta reads consistently higher than Eurofins on all four retests (+4.9% to +7.6%, mean +6.1%) - a systematic method offset, not scatter, and one that favours the brands.
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100