Amino Spiking: How Protein Labels Can Mislead You (and How to Check)
The big number on a protein tub, "24 g protein per serving" or "80% protein", looks simple. But it comes from a lab test with a well-known blind spot, and that blind spot can be used to make a protein look stronger than it really is. Here is how protein is actually measured, what amino spiking is, and how you can check any label in under a minute.
How labs measure protein: they count nitrogen
Almost every protein figure on a food label, including in India, starts with a measurement of nitrogen, not protein. The two standard lab methods, Kjeldahl and Dumas, measure the total nitrogen in a sample. That number is then multiplied by a conversion factor, usually 6.25, to estimate protein. India's labelling rules specify protein as total Kjeldahl nitrogen × 6.25 (6.38 for milk).
The catch: the test cannot tell whether the nitrogen comes from real protein or from something else. Labels therefore show "crude protein" (nitrogen × factor), not "true protein" (actual amino-acid chains).
What is amino spiking?
Because nitrogen tests can't tell protein apart from other nitrogen-rich compounds, they can be gamed. Amino spiking (also called protein spiking) means adding cheap, nitrogen-rich ingredients such as free glycine, taurine or creatine to push up the protein reading without adding real, complete protein.
These ingredients are not harmful in themselves. The problem is that you pay for protein you don't actually get. The most notorious example of nitrogen fraud was the 2007–2008 melamine scandal in pet food and infant formula.
The Indian picture: labels that don't add up
In 2024, a self-funded group of doctors and scientists published the Citizens Protein Project, which tested 36 popular protein supplements sold in India. They found:
- 25 of 36 (69%) contained less protein than their labels claimed, with shortfalls from under 10% to over 50%.
- Some contained more protein than labelled, which the authors flagged as a possible sign of amino spiking.
- Aflatoxins were detected in 5 products, pesticide residues in 3, and lead in 27.
The study has been criticised on its methods, and "detected" does not always mean "above the legal limit". But it is still the largest public test of Indian protein supplements, and it shows why it is worth checking what's in your tub.
Want to try a clean label? Start with the Fizinga Variety Pack: 8 sachets of Cold Coffee and Strawberry, 24 g protein each, with fermented yeast protein as the first ingredient and no added free amino acids.
Why yeast protein needs a closer look
Yeast is a special case, and it matters for anyone buying fermented yeast protein. In whole yeast, 20–30% of the nitrogen is not protein, mostly because yeast is rich in RNA, which contains nitrogen just like protein does. That means a nitrogen test overstates the protein in whole yeast.
The good news: a properly made yeast protein isolate has most of that RNA removed during processing (see How Fermented Yeast Protein Is Made). In an independent 2025 analysis of a commercial yeast protein powder, the measured amino acids added up to 77.05 g per 100 g, almost the same as the nitrogen-based protein figure of 77.55 g. In other words, for a well-made isolate, the label figure and the real protein were very close.
How to check any protein label: 7 quick checks
- Protein per 100 g, not just per scoop. Scoop sizes differ, so "per scoop" numbers aren't comparable. Divide protein by scoop size and multiply by 100.
- Protein percentage. An unflavoured "isolate" should usually be around 80% protein. Flavoured products are lower because of cocoa, flavour and sweetener.
- A full amino-acid profile. Is it printed? For yeast protein, leucine is typically around 8.5–9% of protein and total essential amino acids around 45–47%. An unusually high glycine figure is a red flag.
- The ingredient list. The protein source should come first. Watch for free glycine, taurine or similar amino acids listed separately.
- Regulatory details. In India, look for the brand owner's FSSAI licence number, the manufacturer's address, and "Health Supplement / Not for medicinal use" where applicable.
- Third-party testing. Is there a recent certificate of analysis from an accredited (NABL) lab covering protein, heavy metals and microbes?
- For yeast protein specifically: can the brand tell you the residual nucleic-acid (RNA) level of its ingredient?
For a complete buying guide, read How to Choose a Yeast Protein Powder.
What Fizinga's label says
In every Fizinga Smart Protein flavour, fermented yeast protein is the first ingredient and there are no added free amino acids. Unflavoured gives 28 g protein per 36 g scoop, and Cold Coffee and Strawberry give 24 g. These are our label figures, and independent testing is the right way to verify any brand's claims, including ours.
Frequently asked questions
Is amino spiking illegal in India?
Adding free amino acids is not illegal by itself, but using them to inflate a protein claim misleads buyers. FSSAI licenses brands and samples products, but it does not test every batch before sale, so transparency from brands matters.
How can I tell if my protein is spiked?
Check the ingredient list for free glycine or taurine, and see whether the amino-acid profile adds up to roughly the declared protein. A lab certificate of analysis is the most reliable check.
Is the protein figure on yeast protein accurate?
For whole yeast, nitrogen-based figures overstate protein. For a well-refined yeast protein isolate, independent analysis suggests the difference is small.
What's the best way to compare two protein powders?
Compare protein per 100 g, the ingredient list, the amino-acid profile and third-party test reports, not just the number on the front of the pack.
Shop Fizinga Smart Protein
Sources: FSSAI labelling regulations (2020), Jach et al. (2022), An & Lee (2025), Philips et al. (2024, Citizens Protein Project) via ThePrint and NutraIngredients, and FAO (2013), as reviewed in Fizinga's 2026 research white paper. This article is for general information and is not medical advice.
