Creatinine vs Creatine | Simple Breakdown (Tables Included)

It’s amazing the difference that two extra letters can make in the meaning of a word, and when it comes to the world of fitness supplements, the difference between creatine and creatinine is as distinct as night and day in a lot of ways.

Yet, while the differences between creatine and creatinine are sufficient to set them apart as polar opposites, the similarities between them were once so obvious that some researchers confused the two compounds for one another for centuries. Unfortunately, this led to several false conclusions being drawn that held many people back from embracing the benefits of creatine, or even conceiving that it could be of any value at all.

Nowadays, you are infinitely less likely to make any false connections between the two compounds, but it is still helpful to comprehend the relationship between them, and what it means when you hear that creatinine is present in your supplement instead of the creatine that you were expecting. 

What is Creatine?

While creatine is often characterized as if it were a mysterious chemical supplement, it is actually a simple compound formed naturally by three common amino acids:

• Glycine

• Arginine

• S-adenosyl methionine 

Creatine is attainable in substantial amounts in red meat and some types of fish, and it can also be pieced together through the acquisition of ample amounts of its amino acid components from other food. Regardless of whether you acquire your creatine in its complete form or through its individual amino acids, it is all stored within your skeletal muscle and organs as creatine phosphate.

What is Creatinine?

Simply stated, creatinine is the form that creatine takes once it has been used by your body, and is defined as the byproduct of creatine phosphate from muscle and protein metabolism. 

Interestingly, from a chemical standpoint, creatinine is literally creatine that has been stripped of its water. By comparing the chemical formulas of creatine and creatinine, you’ll find that creatine (C4H9N3O2) is nearly identical to creatinine (C4H7N3O), except that it is missing H20 — or two hydrogen atoms and one oxygen atom — also known as the chemical formula for water.

Where are you most likely to encounter each one?

Through your everyday consumption of food, you will directly encounter creatine when you consume animal protein products, and especially products like beef and herring, which are abundant in creatine.

With this being said, to achieve the level of enhanced muscle performance and recovery associated with supplemental creatine doses, you would need to consume an amount of animal protein that is thoroughly uncomfortable for most people. Because of this, most people in search of creatine tend to discount the creatine they achieve from whole food sources, and only track the creatine they consume through dedicated creatine supplements.

While no one with a goal of holistic health improvement would directly consume creatinine due to its negative side effects, most creatinine ingestion occurs accidentally. Unfortunately, this probably happens more frequently than you might think due to misguided attempts to repackage creatine for convenience. 

Simply stated, you are most likely to encounter creatinine in the form of creatine that has broken down into its harmful byproduct before it could be consumed. In several cases, creatine gummies that were advertised to contain high levels of creatine were instead found to possess negligible amounts of creatine and alarmingly high levels of creatinine. 

This breakdown is owed to the fact that creatine is unstable during processes that can change its chemical structure, and the combination of moisture and heat used to create gummies causes the creatine in the gummies to degrade into creatinine. This is also a common occurrence with liquid creatine supplements, because creatine is prone to rapid degradation while it sits in liquid.

Therefore, you are most likely to inadvertently encounter creatinine when you consume supplements that are advertised to be high in creatine, but whose lack of shelf stability has caused the creatine within them to degrade.

How is Creatine used by your body?

In many circles of fitness and nutrition, creatine is the gold standard by which all other supplements are measured. This is because its effectiveness has been proven time and time again, through rigorous testing, and by the observable performances of both athletes and non-athletes who have benefitted from frequent supplementation with it.

It is for this reason that creatine is beneficial when consumed alone, or when combined with complementary supplements like HMB, or paired with protein in post-workout mass-building formulations.

Energy optimization

Your body stores energy for multiple purposes in the form of adenosine triphosphate, which is more commonly simplified to ATP. However, the work of ATP is most commonly observable during explosive activities that require rapid muscle contraction, like any actions that require quick bursts of energy. 

During sprinting and other varieties of sports performance that inspire your muscles to move rapidly and powerfully, creatine extends the length of time under which your body relies on its ATP-phosphocreatine system. For sprint athletes, this can ultimately result in a further two seconds of all-out activity before their bodies begin to noticeably tire, which can amount to the entire difference between winning and losing in an all-out race.

When you engage in demanding weight lifting or heavy resistance training, creatine increases and intensifies muscle contraction, making it easier for your muscles to exert themselves against resistance. Alternatively, during endurance sports and other types of sports performance that don’t require an all-out effort, creatine acts as a buffer between energy systems, and enhances durability. 

A meta-analysis of 20 studies exploring the effects of creatine on strength concluded that the consumption of creatine resulted in significant increases to both upper- and lower-body strength as measured by one-rep max. (1)

Muscle growth and recovery

In bodybuilding circles, creatine is commonly called upon for its ability to amplify muscle growth. This is accomplished through multiple methods, but it still starts with creatine’s ability to maximize your performance potential.

On the front end, creatine supplementation is associated with increased muscle activity, prompting a greater degree of muscle fiber breakdown during exercise. On the back end, creatine expedites the repair process for muscle tissue, repairing it more completely, maximizing the quality of your body composition, and promptly preparing them for additional bouts of peak performance.

The primary driver behind this accelerated muscle growth is believed to be the energy demands of muscle protein synthesis and the muscle repair process. Because creatine saturates skeletal muscle tissue with ATP, your muscles are provided with an ample supply of energy that can be put to immediate use repairing muscle tissue.

In other worlds, creatine supplementation amplifies sports performance on the front end, and optimizes your body’s repair and recovery process on the back end, resulting in the creation of a higher quantity of muscle mass, and a more desirable body composition in terms of your muscle-mass-to-fat-mass ratio.

A multivariate analysis of 44 studies, each of which lasted at least six weeks, found that creatine supplementation combined with resistance training resulted in significant increases in direct measures of skeletal muscle hypertrophy in both the upper and lower body beyond those achievable with resistance training and a placebo. (2)

Cognitive function

When discussing the many benefits of creatine, most of the emphasis is placed on the improvements that can be made to physical performance. While it is true that the overwhelming number of creatine’s consumers value it for the boost it provides to physical performance, it is equally valuable as a boost to cognitive function and memory.

In 16 randomized controlled trials, creatine was proven to have significant positive effects on memory and attention time, while improving processing speed, with the effects being strongest on test subjects suffering from diseases, individuals between the ages of 18 and 60, and women. (3) 

Moreover, there is further evidence that long-term creatine supplementation isn’t required before benefits to mental health can be achieved. A noteworthy study identified that a single dose of creatine was sufficient to improve cognitive performance and processing speed in sleep-deprived individuals. (4)

How is Creatinine used by your body?

In stark contrast to creatine, there is no discernible benefit to consuming creatinine, which can lead to more frequent feelings of fatigue. In fact, the detection of high levels of creatinine in your body could be an indication of mild to severe health problems ranging from chronic dehydration to kidney dysfunction.

As such, there is no supplement market for creatinine, and as your body responds to creatinine’s presence, either because you’ve expended creatine or accidentally ingested creatinine, it will seek to expel it from your body through urination.

No More Confusion

You can now move forward with a full understanding of what distinguishes creatine, one of most beneficial nutritional supplements in human history, from its waste byproduct, creatinine. 

Fortunately, there will be very few opportunities for you to consume creatinine instead of creatine as long as you stick with creatine supplements whose contents have been confirmed through third-party testing, and avoid creatine supplements that are manufactured using moisture and heat.

Sources

1. Sharifian G, Aseminia P, Heidary D, Esformes JI. Impact of creatine supplementation and exercise training in older adults: a systematic review and meta-analysis. Eur Rev Aging Phys Act. 2025 Oct 8;22(1):17. doi: 10.1186/s11556-025-00384-9. PMID: 41062952; PMCID: PMC12506341.

2. Burke R, Piñero A, Coleman M, Mohan A, Sapuppo M, Augustin F, Aragon AA, Candow DG, Forbes SC, Swinton P, Schoenfeld BJ. The Effects of Creatine Supplementation Combined with Resistance Training on Regional Measures of Muscle Hypertrophy: A Systematic Review with Meta-Analysis. Nutrients. 2023 Apr 28;15(9):2116. doi: 10.3390/nu15092116. PMID: 37432300; PMCID: PMC10180745.

3. Xu C, Bi S, Zhang W, Luo L. The effects of creatine supplementation on cognitive function in adults: a systematic review and meta-analysis. Front Nutr. 2024 Jul 12;11:1424972. doi: 10.3389/fnut.2024.1424972. Erratum in: Front Nutr. 2025 Feb 17;12:1570800. doi: 10.3389/fnut.2025.1570800. PMID: 39070254; PMCID: PMC11275561.

4. Gordji-Nejad, A., Matusch, A., Kleedörfer, S. et al. Single dose creatine improves cognitive performance and induces changes in cerebral high energy phosphates during sleep deprivation. Sci Rep 14, 4937 (2024). https://doi.org/10.1038/s41598-024-54249-9