Our Methodology

Name: CompareWhey
Rating: 4.8

How we collect, verify, and present protein powder data

Full Transparency: We collect data from publicly available sources. When data is missing, we clearly mark it as "N/A" or "Data Pending". We never estimate or create fake data. This page explains exactly how we work.

Data Collection Process

Primary Sources (In Order of Priority)

1
Official Brand Websites
We check the official product pages for nutrition facts and amino acid profiles. This is our most trusted source.
2
Product Labels (Physical or Photos)
When website data is incomplete, we reference actual product labels from retail photos or user submissions.
3
Certificates of Analysis (COAs)
Some brands publish lab reports. We use these for amino acid profiles when available.
4
Retailer Websites
Amazon, Bodybuilding.com, and other retailers sometimes have data the brands don't publish.

What We DON'T Do: We never use AI to generate data, never copy from unreliable sources, and never estimate missing amino acid values. If we can't find it from a trusted source, we mark it as unavailable.

Data Points We Track

Always Available

Brand Name
Product Name
Protein Type (Isolate/Concentrate/etc)
Protein per Serving
Serving Size
Basic Macros (Carbs, Fat, Calories)

Often Missing

Complete Amino Acid Profile (30% missing)
Leucine Content (25% missing)
Non-BCAA Aminos (50% missing)
Vitamin/Mineral Content
Heavy Metal Test Results
Third-Party Certifications

How We Handle Missing Data: We display "N/A", "Data not available", or "—" for missing information. We NEVER fill in estimated values. Our data completeness score shows what percentage of fields we have for each product.

Why We Focus on Leucine

Leucine is the primary trigger for muscle protein synthesis (MPS). Research shows you need 2.5-3g of leucine per serving to maximally stimulate MPS. Yet most comparison sites ignore this critical metric.

Scientific Basis:

•Phillips & Van Loon (2011): Established the 2.5g leucine threshold for young adults
•Burd et al. (2013): Showed older adults need 3-3.5g for same effect
•Norton et al. (2009): Demonstrated leucine as the key BCAA for MPS

Our leucine calculations and thresholds are based on peer-reviewed research, not marketing claims. Every formula we use is referenced to scientific literature.

Our Calculations

Cost Per Gram Leucine

Formula: Price per serving ÷ Leucine grams per serving

This unique metric shows the true value for muscle building, not just protein quantity.

Leucine Threshold Calculator

Base Formula: 39mg leucine × kg body weight

Adjusted for age (×1.25 for 60+) and training status based on research.

Data Completeness Score

Formula: (Filled fields ÷ Total fields) × 100

Shows what percentage of data points we have for each product. Higher = more complete info.

Price & Availability Updates

Not Real-Time: We check prices periodically, not continuously. Prices shown may be days or weeks old. Always verify current pricing at the retailer.

Our current update schedule:

•Popular products: Checked weekly
•Most products: Checked monthly
•New products: Added as discovered
•Discontinued products: Marked but kept for reference

Quality Control

How We Verify Data

Cross-reference multiple sources when possible
Flag products with conflicting information
Update data when formulas change
Welcome user corrections (with proof)

Known Limitations

Cannot independently lab test products
Rely on brand-provided information
May miss formula updates temporarily
Cannot verify marketing claims

Corrections & Contributions

Found an error? Have data we're missing? We genuinely want to fix it. Here's how to help:

1
Send us proof
Photo of label, link to official source, or COA document
2
We'll verify
We check the source and update if accurate
3
Credit given
Contributors are thanked (if desired) in our updates

Submit a Correction

Questions about our methodology? Contact us

Last updated: January 2025 | Version 1.0