Frequently Asked Questions (FAQ)
How is the product data collected?
We use a hybrid approach:
- **Discovery:** Automated scripts periodically scan Amazon search results and product pages to discover new protein product ASINs (Amazon Standard Identification Numbers), including different flavors and sizes (variations). We also use the official Amazon Product Advertising API (PAAPI) to search for products by brand.
- **Detailed Data:** Once we have a list of ASINs, we use the official Amazon Product Advertising API (PAAPI) to fetch the latest, most reliable data directly from Amazon. This includes price, product title, brand, images, and product features/descriptions.
- **Updates:** The data fetching process via the PAAPI is run daily to ensure prices and product availability are as up-to-date as possible.
How are the prices calculated?
- **Price Per Serving:** We take the current price provided by the Amazon API and divide it by the number of servings listed for the product.
- **Price Per Gram of Protein:** This is our primary ranking metric. We calculate this by dividing the total product price by the *total grams of protein* in the container (Servings × Protein Per Serving). This gives the most accurate measure of value.
Note: Extracting serving size and protein per serving relies on parsing information from product titles and descriptions provided by the API. While we use several patterns to capture this data accurately, inconsistencies in how manufacturers list information can sometimes lead to missing or estimated values. We filter out products where essential data (like price, servings, or protein per serving) cannot be reliably determined.
How often is the data updated?
The core product data (especially prices) fetched via the Amazon Product Advertising API is updated daily.
What's the difference between protein types (Whey, Isolate, Casein, Vegan)?
- Whey Concentrate: The most common type, derived from milk. Contains protein, some lactose, and fat. Digests relatively quickly.
- Whey Isolate: Further processed to remove most lactose and fat, resulting in a higher protein percentage (typically 90%+). Digests very quickly. Often preferred by those sensitive to lactose.
- Whey Hydrolysate: Pre-digested whey, meaning it's broken down into smaller peptides for the fastest absorption. Often the most expensive.
- Casein: Also derived from milk, but digests very slowly, providing a sustained release of amino acids. Often taken before bed.
- Vegan/Plant-Based: Proteins derived from sources like peas, rice, soy, hemp, etc. Suitable for vegetarians, vegans, or those with dairy allergies. Often blended to provide a complete amino acid profile.
How do I use the site?
The main table lists protein powders found on Amazon. You can:
- **Sort:** Click on column headers (like "Price/Gram", "Price/Serving", "Protein/Serving") to sort the products. Click again to reverse the sort order.
- **Search:** Use the search bar to filter products by name, brand, or flavor.
- **Click:** Click on a product row to be taken to its Amazon page (using our affiliate link).
Why are some products missing?
Possible reasons include:
- The product wasn't discovered by our scraping or brand search process yet.
- The Amazon API didn't return the product when we requested its details (e.g., temporary unavailability).
- We couldn't reliably extract essential information (price, servings, protein grams) needed for calculations.
- The product was manually excluded via our exclusion list.
Is this affiliated with Amazon?
ProteinPrices.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. As an Amazon Associate, we earn from qualifying purchases. This does not affect the price you pay.