How Protein Index scores WPI.
Every reviewed product is assessed against the same 100-point framework. The Index organises available evidence; it is not a laboratory test, medical recommendation or guarantee of performance.
Product quality
Protein density and flavour-specific nutrition, including the published sugar rule.
Ingredients
Formula simplicity, disclosure and the role of sweeteners, flavours and other additives.
Testing evidence
Accessible finished-product reports, recognised certification and relevance to the reviewed variant.
Source origin
How clearly the whey source, country and manufacturing information are identified.
Value
Current single-pack price normalised per kilogram and per 30g of powder.
Customer experience
Published rating and review volume, adjusted for confidence where appropriate.
Missing price and review evidence
If a comparable Australian dollar single-pack price is unavailable, Value receives 0/12. Customer experience receives 0/8 when a usable published star average and review count are not both verified for the product record. A missing score is an evidence gap, not proof of poor quality. The overall score is the sum of the six displayed factors. Products with missing evidence remain in their flavour group so readers can inspect the other factors and the gaps.
Comparison groups
Chocolate, vanilla and unflavoured products are assessed separately because flavour systems change protein density, sugar and ingredients. We use the closest standard chocolate WPI sold by each provider and do not compare an unflavoured formula against flavoured competitors.
Updates and corrections
Scores may change when prices, formulas, nutrition panels, reports or public customer evidence change. New information is reviewed using the same rules as the original assessment. Evidence score audit: 22 September 2026.
A higher score means stronger performance against this framework within the current comparison group. It does not mean a product is healthier, safer or suitable for every person.