Research
Micronutrients & recovery
Whey protein powders contain significantly higher concentrations of sweet-tasting free amino acids (glycine, alanine, serine, proline, threonine) compared to plant-based protein powders.
If you are choosing between whey and plant protein, be aware that whey naturally contains higher levels of certain free amino acids like glycine and alanine. This difference exists regardless of the total protein content listed on the label.
ModerateSupportsMEDIUM confidence
Notably, amino acids linked to sweet taste such as glycine, alanine, serine, proline and threonine were significantly greater in the majority of whey proteins that directly causes acute disorders in healthy individuals as per the International Council on Amino Acid Science (ICAAS).
Why this rating
The study is a chemical analysis of commercial products, not a clinical trial on human health outcomes.
Source
Quantitative LC-MS/MS Determination of Source-Specific Variations of Underivatized Free Amino Acids in Protein Powders
C. Ranjani et al. · Asian Journal of Chemistry · 2025
mechanism_only · n=18
Read the paper This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →