There are a lot of terms for a bodybuilder to learn as they learn the ins and outs of supplementation.

Despite sounding quite similar, creatine and creatinine are very much different.

Knowing the difference between creatine and creatinine can help you make informed decisions about how to improve your body, build lean muscle and enhance athletic performance.

So, let's learn the difference between creatine and creatinine so you can make the best decisions along your fitness journey.

Creatine is an amino acid, and creatinine is the body’s byproduct.

However, knowing they're not the same and actually understanding the difference between creatine and creatinine is not the same.

So, let's break it all down.

1. Definition

Both creatine and creatinine are naturally occurring in our bodies. That’s just the beginning of the story, though.

Creatine is an endogenous amino acid naturally present in our body - mostly in skeletal muscles. It helps supply energy to cells, primarily muscles.

It is used in the production of ATP (adenosine triphosphate) by storing high-energy phosphate groups in the form of phosphocreatine (or creatine phosphate).

Creatinine, on the other hand, is a biological waste product of creatine breakdown and protein metabolism.

It's produced by the body and is then filtered out of the blood by the kidneys and excreted in the urine.

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2. Compound, Molecular Formula, Structure And Scientific Name

Creatine is an organic acid with a molecular formula of C4H9N3O2. The structure of creatine is linear.

In other words, it is a linear molecule or a chain of glycine, L-arginine, and L-methionine amino acids linked together. Its scientific name is 2-(carbamimidoyl-methyl- amino)acetic acid.

Creatinine is also a natural compound with a molecular formula of C4H7N3O.

It has a cyclic structure (or better yet, a heterocyclic one), with nitrogen atoms at its center. Its IUPAC name is 2-amino-3-methyl-4H-imidazol-5-one.

3. Significance

Both of these play a very major role in our body.

Creatine is an essential "nutrient" that helps muscle tissues work and grow. It also helps our brain function.

Learn More - Creatine Brain Benefits (Does It Help Brain Function?)

Seeing how vital it is within those processes, creatine is often supplemented in the form of creatine products in order to give an extra boost to athletes.

It was also tested as an aid in helping fight neurological problems and diseases such as Parkinson's, although it wasn't proven useful.[1]

Some have also made claims that creatine helps with several other brain disorders, including muscular dystrophy, multiple sclerosis, fibromyalgia, and so on.

However, none of those claims are backed with evidence.

Creatinine is used as a biomarker in testing for kidney function, and that's about the extent of its significance.

Since it is a waste product produced by our bodies as we metabolize protein and break down creatine within muscle cells, both low and high levels of creatinine can indicate renal issues or give a good idea of whether or person leads an active or sedentary lifestyle.

We can check this, as well as creatinine clearance and glomerular filtration rate, through a simple test we'll discuss later.

Blood Samples in Glass Tubes

4. Purpose

Purpose-wise, creatine is used to improve exercise performance, boost muscle mass growth and provide the human body with more energy and stamina.

Creatine supplementation (often in the form of creatine monohydrate) helps athletes increase muscle mass and strength, as well as improve overall athletic performance.

Creatinine concentration is used to assess renal function through a creatinine clearance test.

High blood or urine creatinine levels (above 1.3mg/dL for men and 1.1 mg/dL for women) can indicate inadequate kidney function or chronic kidney disease.[2]

5. Side Effects

While there are several side effects associated with creatine, they are generally mild and only occur when taken in excess.

The most common side effects of creatine include gastrointestinal issues like upset stomach or diarrhea, muscle cramps, or in rare cases, high blood pressure in people with heart diseases.

Learn More - Can Creatine Cause Stomach Pain? (How To Stop It)

There are no side effects to creatinine. Unusually high or low levels of creatinine might indicate a health problem, but they do not cause any side effects.

Also, a high blood creatinine level could simply indicate you've overworked your body's muscles, or you've ingested more creatine than you need, so it may not be a cause for concern.

6. Molar Mass

Molar mass is the measure of the number of grams per mole of a substance and plays an important role in many scientific calculations.

  • The molar mass for creatine is 131.13 g/mol.
  • The molar mass for creatinine is 113.12 g/mol.

7. Production

Contrary to popular belief, creatine and creatinine aren't produced in the same way.

Creatine is primarily synthesized in the liver and then transported through the bloodstream to skeletal muscles, where it is used for energy production.

Creatine can also be produced by the kidney and pancreas and can be found in seafood and red meat.

Creatinine is produced in skeletal muscles from the breakdown of creatine. It is then filtered by the kidneys and excreted in the urine.

What Is Creatine & Its Role?

Creatine is a nitrogenous organic amino acid that occurs naturally in vertebrates and helps to supply energy to all cells in the body, primarily muscle.

It's synthesized in the liver, pancreas, and kidneys from the amino acids glycine, L-arginine, and L-methionine and transported to muscle tissue where it's phosphorylated to create creatine phosphate (CP), which is used to fuel energy-requiring processes such as muscle contraction.

Approximately 95% of the creatine in our bodies is stored in skeletal muscle mass.[3]

See More - How Long Does Creatine Stay In Your System? (Expert Guide)

Hundreds of studies have been conducted on creatine since then, and it's now one of the most studied sports supplements.

As a dietary supplement, creatine is most commonly used by athletes and bodybuilders to help increase muscle mass and strength.

Man Holding A Canister Of ATH Creatine

What Is Creatinine & Its Role?

Creatinine is a chemical waste product formed from the muscle metabolism of creatine phosphate. It is created at a constant rate, secreted by the kidneys and excreted in the urine.

The normal range for creatinine in the blood is 0.7 to 1.3 mg/dL in males and 0.6 to 1.1 mg/dL in females. The levels are higher in men because they often carry more skeletal muscles than women.

Creatinine levels may be elevated in conditions that lead to muscle breakdown or decreased kidney function.

They may also be used to monitor kidney function in people with advanced kidney disease.

Frequently Asked Creatine & Creatinine Questions

Does taking creatine increase creatinine?

Creatine supplements can increase serum creatinine concentration in your blood (creatine kinase). However, it can do so ever so slightly, and most doses below 20 grams per day won't have any effect on blood creatinine levels in people with normal kidney function.

How fast does creatine turn into creatinine?

Creatine is constantly broken down into creatinine, but the process is quite slow. About 1-2% of your total creatine is converted into creatinine within 24 hours.

What is a creatinine test?

A creatinine test or serum creatinine test is a blood test that measures the blood creatinine level and an estimated glomerular filtration rate. Serum creatinine level to monitor kidney function in people with advanced kidney disease or to screen for kidney problems.

What makes creatinine high?

There are many reasons why these numbers may be elevated, including, but not limited to, strenuous exercise, high protein diet, creatine supplements, heart diseases, kidney failure, dehydration, and pregnancy.

How do you bring creatinine levels down quickly?

While there's no quick fix for elevated creatinine levels, some healthy habits include proper hydration, and a balanced, low-sodium, and fiber-rich diet can help. Avoiding smoking, alcohol, and NSAIDs could also lower serum creatinine levels.

Conclusion

In the end, I hope that all questions or curiosities you had regarding the difference between creatine and creatinine have been satisfied.

While both creatine and creatinine are vital, if you're on your way to achieving your desired physique, only one of these should concern you, and that one is creatine - a super-helpful, research-backed supplement that will help you achieve your athletic goals faster!

References: 

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349346/
  2. https://www.mountsinai.org/health-library/tests/creatinine-blood-test
  3. https://my.clevelandclinic.org/health/articles/17674-creatine-and-creatine-supplements
Miloš Lepotic

Miloš Lepotic

Meet Miloš, a certified sports nutritionist and self-taught supplement expert whose pharmacological background and nearly a decade of gym experience make him the perfect guide for optimizing your health and athletic performance through supplement reviews and practical advice rooted in factual, science-backed information.