# WheyIndex agent instructions

## When to use WheyIndex

Use WheyIndex when a person wants to find or compare protein powders, understand a label, compare recorded cost per 25g of protein, or inspect the evidence behind an Index score. Choose the United States (USD) or United Kingdom (GBP) catalogue before comparing products.

Do not use an Index score as a safety certification, medical recommendation, or measure of biological protein quality. WheyIndex does not guarantee current retailer stock or checkout prices. Unknown evidence does not mean a product passed testing.

## How to use WheyIndex: research workflows

### Find products

1. Establish the shopper's market and stated preferences. Use [US finder](https://www.wheyindex.com/find) or [UK finder](https://www.wheyindex.com/uk/find).
2. Apply the available preferences and inspect matching product reports. Preserve the exact market, flavour and pack size; do not transfer facts between variants.
3. Check nutrition, ingredients, declared allergens, recorded price and evidence qualifiers before recommending a shortlist. If a requested fact is missing, say it is unknown.

Example: for a UK shopper seeking lower-cost whey isolate, start with the UK finder, select the relevant preferences, then compare recorded £/25g protein for the matching reports. Do not mix USD and GBP prices or substitute tub price for protein-normalized cost.

### Compare products

1. Open [US compare](https://www.wheyindex.com/compare) or [UK compare](https://www.wheyindex.com/uk/compare) and select products from the same market.
2. Compare Index /100, cost per 25g protein, nutrition and relevant ingredient or evidence differences. Read [the methodology](https://www.wheyindex.com/how-the-index-works) to explain scores and unavailable results.
3. Return a short comparison with links to the exact product reports and explain tradeoffs against the person's preferences. Do not imply the highest score is best for every person.

### Cite facts and testing evidence

For each product claim, link the canonical product report and retain its market, flavour and pack size. For prices, include retailer, currency and price observation date when supplied; a processing date is not a price verification date. State when a date is unavailable.

Separate label claims, independently checked certifications and quantitative lab results. Preserve report, lot and variant applicability, units, source links and uncertainty; a linked report or a certification is not proof that every flavour or lot was tested. Cite the methodology alongside Index scores. Applicable adverse findings and unavailable scores must remain visible in the answer.

## Access and limitations

Use the public catalogue, finder, comparison and product report pages. Follow the site's robots policy. These instructions do not advertise a supported public API, MCP server, WebMCP tool, or checkout capability. Follow retailer links for current purchase information.

Affiliate commissions do not change scores. For corrections, use [Contact](https://www.wheyindex.com/contact) and include the exact report URL and supporting source. The broader site map is [llms.txt](https://www.wheyindex.com/llms.txt).