How this is calculated

• Every whey protein listing of 500g or more (concentrate, isolate, hydrolysed and blends) is compared with its own price at the previous scan. Creatine is not included.
• The average change across those listings is chained scan to scan, so a retailer or product added later never shifts the line up or down.
• Sale prices count. Dips are usually a retailer-wide sale and the climb after is the sale ending.
• Single moves over 50% are left out — they are almost always a listing switching size or variant, not a real price change.
• We scan weekly. A dashed segment means there were no scans in that period.

More on how we collect prices in the methodology.