Creatine and creatinine are two terms often heard side by side in the health and fitness space.

Their similar names cause much confusion, leading many to conflate the two or wrongly compare creatine versus creatinine.

However, creatine and creatinine are distinct compounds with unique functions in our bodies.

In this article, you’ll learn the differences between creatine vs. creatinine and gain evidence-based insights into how and why understanding the distinction is vital.

Understanding Creatine and Creatinine

Before comparing the differences between creatinine vs. creatine, it’s important to grasp what each substance is and its role in the body.

Creatine

Creatine is a compound found naturally in human and animal muscle composed of the amino acids L-arginine, glycine, and methionine

Your kidneys and liver produce creatine, and you can also absorb it from foods like red meat, fish, and eggs. Your body stores this creatine in your muscles to help produce energy

Creatine supplements are popular among athletes and gym-goers because they have numerous muscle-building and performance-enhancing benefits.

Creatinine

Creatinine is a waste product found in the blood that comes from the breakdown of creatine. 

In other words, when your muscles create energy from stored creatine, they produce creatinine. 

Since the body makes creatinine at a fairly consistent rate, the level of creatinine in the blood is a reliable marker for assessing kidney function. This is why doctors check blood creatinine levels when screening for kidney disease.

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Creatine vs. Creatinine: Key Differences

When it comes to creatine vs. creatinine, it’s vital to understand that they’re distinct compounds with different uses and functions. 

Creatine is a compound that helps muscles produce energy. 

The process begins with adenosine triphosphate (ATP), the basic unit of energy in cells. When muscle cells use ATP, they split it into smaller molecules. Afterward, they “reassemble” the fragments back into ATP for reuse.

The more ATP your cells can store and the faster your body can regenerate it, the more “work” you can do. Creatine expedites ATP production by donating a molecule to adenosine diphosphate (ADP)—an ATP precursor—making ATP production quicker.

Taking creatine supplements increases the creatine in your cells, allowing you to work harder for longer.

Creatinine, on the other hand, is the chemical byproduct when your body converts ADP to ATP.

Healthy kidneys filter creatinine out of the blood and eliminate it from the body through urine. Doctors use creatinine levels in blood tests to screen for kidney problems because high creatinine levels may indicate that your kidneys aren’t filtering blood properly.

Doctors also calculate the glomerular filtration rate (GFR) using blood creatinine levels. GFR measures how fast your kidneys remove waste from your blood. It’s a more precise indicator of kidney health and helps diagnose kidney disease.

Does Taking Creatine Increase Creatinine Levels?

Taking creatine supplements can increase creatinine levels in your blood. This happens because as you add more creatine to your body, it turns more of the creatine into creatinine, increasing blood creatinine levels.

Some people worry this might affect their kidneys since high creatinine levels can signal kidney problems. However, this is a misunderstanding.

While elevated creatinine levels can be a red flag for kidney issues, the increase caused by creatine supplements is simply due to your body processing the extra creatine, not a sign of kidney damage.

Why, then, does this concern persist?

Perhaps because early research suggested creatine might be harmful to the kidneys.

These early findings aren’t as convincing as they may seem, though. Most came from individual case studies (studies of one person) or experiments on rats with impaired kidneys, so it would be unwise to apply them to all humans.

Moreover, extensive subsequent research shows that creatine doesn’t negatively affect kidney health. This holds even for people with health issues like diabetes or kidney damage and even if you take large doses for long periods.

Some research even challenges the idea that creatine meaningfully increases creatinine, though this is still a point of contention.

The only potential problem with creatine is that it can make your body hold on to water, which can be an issue for people with certain kidney conditions that already cause them to retain water.

One case study found that a person with kidney damage saw their kidney function worsen when they took creatine, then improve when they stopped taking it. This suggests that some people who need to avoid excess water retention, especially those on diuretics, should probably skip creatine.

For everyone else, creatine is safe and doesn’t threaten kidney health.

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Creatinine vs. Creatine: FAQs

FAQ #1: Is creatinine the same as creatine?

Creatinine is not the same as creatine. Creatinine and creatine are related, however. Creatine helps make and store energy in muscle cells. Creatinine is a waste product created when the body breaks down creatine for energy.

FAQ #2: Is creatine OK for kidneys?

Creatine is fine for your kidneys, provided you have healthy kidneys to begin with. Taking creatine supplements may increase blood creatinine levels, which can indicate kidney disease in some scenarios. However, research shows that creatine supplements don’t cause kidney damage.

FAQ #3: What happens if creatinine is high?

If creatinine levels are high, doctors may order blood tests to measure glomerular filtration rate (GFR) to evaluate kidney function. They may also gather information about your diet and supplement regimen to determine what’s causing elevated creatinine levels. 

FAQ #4: What’s the best creatine?

Research shows that creatine of any kind improves athletic performance in many ways. However, creatine monohydrate is the most studied, safe, and affordable. For a natural source of micronized creatine monohydrate that includes other ingredients that enhance muscle growth and improve recovery, try Recharge.

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