Amino Acid Spiking Explained: How to Spot Low-Quality Protein Powders
Learn how amino acid spiking inflates protein labels, how to spot low-quality powders, and how to choose filler-free protein supplements.
Protein prices have risen significantly over the past several years, and unfortunately, not all supplement companies have responded with transparency. Instead, many brands have taken shortcuts to reduce production costs while charging consumers premium prices. One of the most misleading practices to emerge from this trend is amino acid spiking.
If you’ve ever scored what seemed like an unbelievable deal on protein powder, there’s a chance you weren’t actually getting the high-quality protein you thought you were paying for.
What Is Amino Acid Spiking?
Amino acid spiking occurs when manufacturers add cheap, free-form amino acids to protein powder instead of using more expensive, complete protein sources like whey or milk protein. Because protein content is commonly measured by nitrogen levels, these added amino acids can artificially inflate the protein number on the label.
The most common offender is glycine. Glycine is a non-essential amino acid that is inexpensive and contributes nitrogen, but it provides little to no benefit for muscle growth. In other words, it boosts the protein number on the label without delivering the muscle-building value consumers expect.
How Protein Companies Get Away With It
Current protein testing methods cannot distinguish between nitrogen from intact protein and nitrogen from free amino acids. This creates two common labeling scenarios:
Some companies do not disclose the added amino acids at all, labeling the product as pure whey protein even though a portion of the protein grams comes from fillers. Several products have already been exposed through advanced testing.
Other companies list amino acids like glycine or taurine on the ingredient panel but still count them toward the total protein grams. This means a label claiming 30 grams of protein may actually deliver far less muscle-building protein.
Either way, the consumer loses.
How to Identify Amino Acid–Spiked Protein Powders
While it’s impossible to detect undisclosed spiking from a label alone, many products provide warning signs if you know what to look for.
Check the ingredient list under the supplement facts panel. If you see glycine, taurine, creatine, or other free-form amino acids listed in a protein powder, it’s a red flag. There is no legitimate reason for these ingredients to be added to a protein supplement.
Avoid products that list mono- and diglycerides. Despite how harmless the name sounds, these are forms of trans fats that can legally be listed as zero grams due to labeling loopholes.
Steer clear of corn syrup solids and maltodextrin. Corn syrup solids are nutritionally similar to high-fructose corn syrup, and maltodextrin is essentially sugar that doesn’t have to be labeled as such. Both are commonly used to cut costs while misleading consumers.
Choose Filler-Free, Transparent Protein
A high-quality protein powder should have a short, clean ingredient list and clearly disclose the type and quality of protein used. If you see an excessively long list of fillers, sweeteners, and additives, chances are the product is being diluted with low-value ingredients.
Choosing a filler-free protein helps ensure you’re actually getting the muscle-building nutrition you’re paying for, not artificially inflated numbers.
Shop smarter, read labels carefully, and always choose transparency over flashy marketing. Just one more reason to #SelectTheBest.