Amino Acid Spiking
Amino acid spiking is when manufacturers add cheap free amino acids (taurine, glycine, glutamine) to a protein powder to inflate the total nitrogen content. Because protein content is measured by nitrogen, spiked products test higher than the actual intact protein they contain.
Why It Matters
Spiking was a widespread problem in the early 2010s and led to several class-action lawsuits. Modern testing (Labdoor, NSF, Informed Sport) detects spiking by measuring intact protein separately from free amino acids. If you stick to NSF, Informed Sport or USP-certified products, spiking is essentially eliminated.
How to Spot It on a Label
Watch for added free aminos on the ingredient list (taurine, glycine, glutamine) shortly after the protein source. Some are legitimate; large amounts are spiking. Independent testing (Labdoor) publishes a 'protein content vs label claim' score for hundreds of products.
Examples from real products
Related Terms
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