What Is Amino Acid Spiking and Should You Be Worried About It?

We take for granted that the information on a protein powder’s nutrition facts panel is accurate. While many reputable supplement companies create great products, some brands try to cut corners to save money through a method called “amino acid spiking”.

Amino acid spiking is when a supplement company fills a protein powder with cheap amino acids instead of whole protein, which tricks the protein quality test and makes the product look higher in total protein than it is. This isn’t dangerous to your health, but you could be wasting money and missing out on results. 

You might have heard about some companies coming under fire for amino acid spiking and wonder about the impact on you and your results. You might also wonder how to identify if a product is doing this.  Below I have all the answers for you.

Key Takeaways

  • Amino acid spiking isn’t very common anymore because consumers are becoming more educated and putting pressure on supplement companies to produce higher-quality products.
  • If it sounds too good to be true, it probably is. If a product boasts high levels of protein but costs much less than anything else on the market, there’s a good chance it doesn’t meet its label claims.
  • When looking for a protein powder, find one that is third-party tested and discloses its test results free for the public, like Transparent Labs Whey Protein (click to read my review).

What Is Amino Acid Spiking?

Before we can go into detail about what amino acid spiking is, it’s important to understand how protein content and quality are tested.

Protein powders undergo what is called a nitrogen test. An independent lab typically does these tests. Ideally, this lab should be an unbiased third party, and the best-case scenario is that the protein supplement company will publicly disclose its results. 

Nitrogen is not found in carbohydrates or fats but is present in the amine group of a protein. 

Since nitrogen is unique to protein, companies will test the total nitrogen content of the protein powder and then infer the total protein content from that number. 

Amino acid spiking is the act of using low-grade amino acids to make the overall protein content of a product look higher on a nitrogen test. 

Since nitrogen is present in the individual amino acids, a company will cut costs by adding higher levels of less expensive amino acids (like glycine and lysine) instead of adding the more expensive complete protein. 

The nitrogen test cannot accurately distinguish between complete protein and individual amino acids. It will give the impression that a product is high in protein because of its high nitrogen content. 

When companies do this, the label might claim that the product has 25g of protein, but in reality, it could be as low as 10-15g of complete protein. 

I don’t intend for this to turn into a fear-mongering article about protein powders. There are enough of those on the internet already based mostly on fiction and misinterpretation.

The truth is that, as consumers like you become more educated on supplement quality, you’ve put pressure on supplement companies to improve the quality of their products. As a result, issues like amino acid spiking are less prevalent now than they used to be (i.e. in the early 2010s). 

The Difference Between Protein and Amino Acids

You might be asking yourself why using individual amino acids differs from using complete protein.

Proteins are made up of 20 different amino acids. Some of these amino acids are called essential amino acids. Our bodies cannot manufacture them on their own, and those amino acids need to be obtained through diet. 

Other amino acids are non-essential. Our bodies can make enough of those amino acids, and they don’t need to be obtained through food. 

There are also a few amino acids that are considered conditionally essential. With these few, the body normally makes enough of them on its own. But in special cases, such as illness, injury, or prolonged stress, the body cannot replenish them fast enough, and supplementation through the diet is required. 

Here’s a quick breakdown of your amino acids: 

EssentialNon-EssentialConditionally Essential
Aspartic Acid (or Acetate)
Glutamic Acid (Glutamate)

All animal proteins (protein coming from red meat, poultry, fish, eggs, and dairy) are called complete proteins. A complete protein contains all of your essential amino acids. 

Some plant-based proteins, by contrast, are called incomplete proteins because they don’t contain all essential amino acids. Brown rice protein, for example, has no threonine and has low levels of lysine.

Is Amino Acid Spiking Bad? 

Amino acid spiking isn’t bad in the sense that you are at risk of becoming sick if you consume a spiked product. 

In fact, there are benefits to consuming amino acids like glycine and lysine, like supporting cardiovascular health and potentially reducing anxiety.

However, for health, performance, or body composition reasons, you might be trying to hit a specific amount of protein each day.

If you consume a product that is amino acid spiked, you may count your protein powder as a complete source of protein but get as low as half of the amount advertised. 

This could stall your progress and leave you feeling frustrated. Even though you are doing “everything right” as per your diet, you’re still falling short on your total daily protein intake. 

Is Amino Acid Spiking Legal in the Supplement Industry?

Technically, there isn’t a law against amino acid spiking as long as the amino acid content is still displayed on the label. This just puts the responsibility on you, the consumer, to know what to look for. 

So, it’s not illegal, but it’s definitely a shady practice.

Though the FDA oversees the regulation of nutrition supplements, there is little overall regulation. 

When asked to comment on a lawsuit surrounding the brand MusclePharm and its alleged amino acid spiking, FDA press officer Jennifer Dooren said:

“FDA requires that dietary supplements be labeled in a manner that is truthful and not misleading. With regard to the labeling of protein content, FDA’s expectation for proper nutrition labeling is that firms will evaluate the protein content from actual protein sources – not other nitrogen-containing ingredients such as individual amino acids – and label the products consistent with the results of such evaluations.”

My interpretation is that while the FDA expects companies to evaluate total protein content, it doesn’t sound like a definitive requirement

Furthermore, there are different regulations in different countries. Since many brands ship internationally, you could be buying products from a country with fewer regulations, increasing the risk that your product is spiked. 

Brands Caught With Amino Spiking

Between 2014 and 2015, many companies came under fire for allegedly amino acid spiking their products. 

Class action lawsuits were brought up against Body Fortress (2014), IsoPure (Nature’s Best) (2014), MusclePharm (2015), and Muscletech for having total protein content well below what was advertised on their labels and using individual amino acids like glycine and creatine to make their product appear higher in total protein.  

Specifically from the legal documents on the case against MusclePharm, the plaintiff claimed that after testing the MusclePharm product, the total protein content was around 19.4g as opposed to the 40g claimed on the label. 

I haven’t been able to find resolutions in any of these cases. The newest update I could find was from 2018 regarding the IsoPure trial, which had not reached a resolution. For the most part, we see a lot of these cases tied up in legal red tape. 

My honest opinion, as both an industry insider and what I gather from the fallout of these trials, is that supplement companies have stepped up their game since then and understand that they are under scrutiny. 

Some brands now provide certificates of analysis or composition for their products for each individual lot number to reassure consumers that what they are taking is in fact, complete protein. 

certificate of composition
certificate of analysis

There are also CGMP (Current Good Manufacturing Practice) regulations put forth by the FDA. These require the manufacturers/packers/processors of health supplements to take steps to ensure that the product contains the ingredients and strength that it claims to have.

While some companies will always try to find loopholes and shortcuts, seeing a “CGMP Certified” logo on your product is a small level of reassurance that the company has done its minimum due diligence to ensure the safety and quality of your protein. 

CGMP Certified

How To Check If Your Protein Has Amino Spiking? (4 Tips

How to check if your protein has amino spiking

1. Find a Third-Party Tested Brand

The most surefire way to identify a product that is not amino acid spiked is to find one that is third-party tested and publicly shares the results of those tests. 

Some brands will advertise that they are third-party tested but don’t disclose the results of those tests anywhere. 

It would be nice to assume that all of this third-party testing is done by an unbiased and independent laboratory. But if history has taught us anything, it’s that companies will cut corners and cheat to make their products look better. 

To be confident that your product is genuinely tested, find companies like Transparent Labs and Believe Supplements, who offer certificates of analysis and/or certificates of composition for all of their products and each specific lot number tested. 

I recently reviewed Transparent Labs’ whey protein powder and truly believe it’s one of the best protein powders on the market. Check it out if you’re looking for a high-quality, third-party-tested protein powder.

You can also look for NSF/Informed Choice Certified products. These have undergone specific testing to ensure the quality and accuracy of ingredients to certify the products are safe for elite athletes who have to go through drug testing in their sports. 

Either of these logos on your protein powder is an indication of high-quality and third-party-tested products.

2. Check the Ingredient Label and List

Check the ingredient list to see if individual amino acids are listed.

For example, you might see “whey concentrate” early on in the ingredient list and then see “lysine” listed a few ingredients down.

If you see this, it’s a hint that the brand may have buffed up its total protein content with amino acids. 

Ingredient Label

Take this ingredient label for instance. It’s possible that the product contains a complete 25 grams of whey protein, as well as added glutamine, leucine, isoleucine, and valine. 

But we also can’t rule out the possibility that the company used those amino acids to make the nitrogen content of its protein look higher. 

Compare that to the Transparent Labs nutrition label below, where quantities of the ingredients are clearly labeled. The non-medicinal ingredients list is much more concise, with no evidence of extra amino acids added in. 

Transparent Labs nutrition label

3. Find an Amino Acid Breakdown

As per the FDA regulations mentioned above, a company cannot be accused of deceptive tactics if it clearly states the amino acid breakdown of its product. 

Each protein has a different makeup of amino acids. Whey protein specifically is naturally high in the following amino acids: leucine, lysine, isoleucine, threonine, valine, and glutamic acid. 

If you can find the amino acid breakdown of your product, look for these amino acids to be found in the highest concentrations. 

On the other hand, if you find other amino acids like glycine to be really high, there’s a possibility that the company has added extra glycine in place of complete whey protein. 

amino acid breakdown of Nutrabolics Hydropure

If we look at the amino acid breakdown of Nutrabolics Hydropure, we see that the amino acids found in the highest quantity include glutamine, aspartic acid, leucine, lysine, threonine, proline, valine, and isoleucine. 

There is a substantial cross-over between this list and the amino acids mentioned above as being found in the highest concentrations of whey protein.

This is a good indication that this product uses complete whey protein and has disclosed that these amino acids are all naturally occurring, meaning the company hasn’t added them artificially. 

4. Evaluate the Price

I love a bargain as much as the next person, but when it comes to protein supplements, you get what you pay for. 

If you find a product that is substantially cheaper than other comparable products on the market, there’s probably a reason why. Possible reasons include the addition of fillers like sugars or amino acid spiking. 

The typical cost of whey proteins on the market right now is anywhere between $1.10 and $2.00 per serving. If you find a brand that is a significant outlier to that on the low end – especially during or after the year 2022, when the cost of whey protein skyrocketed – there has to be a reason that brand can offer its product so cheap (i.e., it doesn’t contain the quality or quantity of ingredients it claims to).

Which Protein Powder Does Not Have Amino Acid Spiking?

Without a doubt, my top recommendation for a protein powder that does not have amino acid spiking is Transparent Labs. 

On its website, Transparent Labs offers certificates of analysis, which break down the testing results for quality and purity for each individual lot number of its products and tests for things like gluten to certify its products as gluten-free. 

It also offers certificates of composition for its products, demonstrated below, which clearly show the breakdown of protein versus flavoring in its products with the protein content coming from a whole protein source. 

Transparent Labs certificate of composition

What To Do If You Already Bought Protein That Has Protein Spiking?

First things first, you don’t have to immediately dump out your product if you suspect it is amino acid spiked. 

Consuming a product that has extra amino acids in place of complete protein is not inherently harmful to your health. As well, there will still be some benefit to consuming the protein powder because you’ll still get some protein from it. 

There are also health benefits to consuming individual essential amino acids, ranging from the maintenance of hair, skin, and nails to muscle recovery to increased immune function. It’s impossible to tell exactly which benefits you might reap, however, if the company doesn’t disclose which amino acids it’s added to its product’s formula. 

If the product is labeled at 25 grams of protein, I recommend tracking it as half that quantity to err on the side of caution and ensure you are hitting your overall protein goals in the day. 

You could mitigate the potentially lower protein content of the spiked protein by mixing it with a higher-quality protein powder or adding the protein powder to other protein-rich foods like Greek yogurt or milk.

Other Things To Look For When Buying Protein Powder


Ding, Y., Svingen, G. F., Pedersen, E. R., Gregory, J. F., Ueland, P. M., Tell, G. S., & Nygård, O. K. (2015). Plasma Glycine and Risk of Acute Myocardial Infarction in Patients With Suspected Stable Angina Pectoris. Journal of the American Heart Association, 5(1), e002621. https://doi.org/10.1161/JAHA.115.002621

Smriga M, Ando T, Akutsu M, Furukawa Y, Miwa K, Morinaga Y. Oral treatment with L-lysine and L-arginine reduces anxiety and basal cortisol levels in healthy humans. Biomed Res. 2007 Apr;28(2):85-90. doi: 10.2220/biomedres.28.85. PMID: 17510493.

Gorissen, S. H. M., Crombag, J. J. R., Senden, J. M. G., Waterval, W. A. H., Bierau, J., Verdijk, L. B., & van Loon, L. J. C. (2018). Protein content and amino acid composition of commercially available plant-based protein isolates. Amino acids, 50(12), 1685–1695. https://doi.org/10.1007/s00726-018-2640-5

About The Author

Jennifer Vibert

Jennifer Vibert is a Certified Strength and Conditioning Specialist, Nutrition Coach, and supplement store manager. She has a Bachelor of Kinesiology with a major in Fitness and Lifestyle and a minor in Psychology from the University of Regina. She is a Certified Nutrition Coach through Precision Nutrition, with a passion for helping clients learn the fundamentals of nutrition and supplementation in order to build healthy, sustainable habits.

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