Creatine vs Creatinine: Key Differences You Should Know


Time to read 5 min

If you're in the fitness world or have any interest in bodybuilding, you've probably come across creatine vs creatinine. These two compounds sound incredibly similar, but they serve different roles in the body. Understanding the nuances between creatine vs creatinine is vital if you're planning on supplementing your diet or if you're worried about kidney function.

Understanding Creatine and Creatinine

Creatine is an amino acid derivative produced naturally in the liver, kidneys, and pancreas. It's also available in small amounts in foods like meat and fish, and it's widely used in supplement form by athletes and fitness enthusiasts for improving exercise performance and increasing muscle mass.

Creatinine, on the other hand, is a waste product that comes from the natural breakdown of muscle tissue and creatine. It's eliminated from the body solely by the kidneys and is commonly measured in blood and urine tests as an indicator of kidney function.

Functions of Creatine and Creatinine


Creatine primarily acts as a backup for ATP (adenosine triphosphate), the molecule that provides energy for various cellular functions. In high-intensity activities like sprinting or weightlifting, creatine gets converted to creatine phosphate, which then helps replenish ATP levels. This mechanism essentially provides a rapid source of energy and can help improve performance and endurance.

  • Improved Performance: Studies have shown that creatine can improve exercise performance, particularly in activities that involve short bursts of high-effort output like sprinting or weightlifting.
  • Muscle Growth: Creatine has been found to promote muscle growth by increasing the water content in muscle cells and contributing to protein synthesis.
  • Brain Function: Emerging research suggests that creatine may also support cognitive function, although more studies are needed in this area.


Creatinine doesn't offer any benefit in terms of performance enhancement or energy provision. Instead, its levels in the blood and urine serve as a marker for how well your kidneys are working. Elevated creatinine levels usually indicate impaired kidney function, though it can also be temporarily elevated in situations like dehydration or excessive meat consumption.

  • Waste Product: Creatinine is a byproduct of creatine metabolism and muscle breakdown. It doesn't serve a functional or beneficial purpose in the body.
  • Kidney Function Indicator: Levels of creatinine in the blood and urine are commonly used to assess how well the kidneys are filtering waste products from the bloodstream.
  • Excretion: The body aims to eliminate creatinine, usually via the kidneys and ultimately through urine, to maintain a balanced internal environment.

Differences between Creatine and Creatinine

While their names may confuse some, creatine vs creatinine are distinctly different in function and purpose. Creatine is beneficial for energy metabolism, particularly during high-intensity exercise. Creatinine, by contrast, serves no beneficial purpose and is something the body aims to get rid of.

Another key difference lies in how they're processed by the body. Creatine can be absorbed from dietary sources and synthesized within the body. It can also be stored in the muscles for later use. Creatinine, however, isn't stored; it is filtered out by the kidneys and expelled from the body via urine.

Does Creatine Use Affect the Level of Creatinine?

Yes, taking creatine supplements can temporarily increase creatinine levels. Since creatinine is a byproduct of creatine, higher levels of creatine in the body can lead to higher creatinine levels. However, this increase is generally transient and returns to normal once you stop taking the supplement. Importantly, elevated creatinine levels due to creatine supplementation are usually not an indicator of kidney damage but rather a consequence of increased creatine metabolism.

What Else Can Increase Creatinine?

Elevated levels of creatinine in the blood are commonly associated with impaired kidney function, but this is not the only reason why you might see an uptick in this waste product. There are several other factors, conditions, and lifestyle choices that can influence creatinine levels.

  • Diet: A diet high in red meat and other protein-rich foods can contribute to increased creatinine levels. That's because protein metabolism directly results in creatinine formation.
  • Dehydration: When you're dehydrated, your blood volume decreases, which can result in higher concentrations of substances like creatinine.
  • Medications: Certain medications can interfere with how your kidneys filter waste products, leading to increased levels of creatinine. These medications include some antibiotics, chemotherapy drugs, and antihypertensives.
  • Intense Physical Activity: Heavy exercise, especially activities that involve muscle breakdown like weightlifting, can increase creatinine levels temporarily.

It's essential to consider these factors if you find elevated creatinine levels in your blood tests, as they could indicate more serious underlying issues.

Is Creatine Safe?

For most people, creatine is a safe and effective supplement. Creatine is one of the most extensively studied supplements and multiple studies have found that short-term and long-term use of creatine does not pose significant health risks.ย 

That said, it's crucial to take into account some safety considerations. Because creatinine is a marker for kidney function, individuals with preexisting kidney conditions should be extra cautious. Dosage and water intake are other important considerations; following the recommended guidelines can reduce the risk of potential side effects.

The Bottom Line

So, when you hear the terms "creatine vs creatinine," remember they're not interchangeable, even though they sound almost identical. Creatine is a performance-enhancing compound found in dietary sources and supplements, while creatinine is a waste product that serves as an indicator of kidney function.

Understanding the differences can help you make informed decisions about supplementation and give you a better understanding of your overall health. Keep in mind that while creatine is generally safe, it can temporarily increase creatinine levels, which could be misinterpreted in the absence of context.

FAQs about creatine vs creatinine

Is creatinine the same as creatine?

No, creatinine and creatine are not the same. While both are related to muscle metabolism, creatine is an amino acid derivative that serves as an energy reserve and is used to enhance athletic performance. Creatinine, on the other hand, is a waste product formed during the breakdown of creatine and muscle tissue. It serves as a marker for kidney function but has no beneficial role in the body.

Does taking creatine raise creatinine levels?

Yes, taking creatine supplements can temporarily elevate creatinine levels. This increase is generally a result of enhanced creatine metabolism and not an indicator of kidney damage. The levels typically return to normal after discontinuing the supplement.

How fast does creatine turn into creatinine?

The rate at which creatine converts to creatinine can vary among individuals and depends on several factors such as metabolism, physical activity, and overall health. In general, creatine continuously converts to creatinine at a slow rate, and the conversion is sped up when creatine is broken down for energy during high-intensity activities.

Is creatine OK for kidneys?

For most healthy individuals, creatine supplementation is considered safe for the kidneys. However, those with preexisting kidney conditions should consult a healthcare provider before starting any creatine supplementation.

What happens if creatinine is high?

High creatinine levels could be an indicator of impaired kidney function, though they can also result from other factors like dehydration, high protein diet, and certain medications. Elevated creatinine levels should be evaluated by a healthcare provider to diagnose the underlying cause accurately. If kidney dysfunction is confirmed, further intervention and treatment may be required.