Does Creatine Harm the Liver or Kidneys? Separating Fact from Fiction

November 25, 2025 •

4 min read

Decades of research support the safety profile of creatine, a widely used supplement for enhancing athletic performance and muscle mass. This extensive scientific backing helps definitively answer the common question: does creatine harm the liver or kidneys?

Quick Summary

Extensive research indicates that creatine supplementation, when taken at recommended doses by healthy individuals, does not cause harm to the liver or kidneys. Misconceptions often arise from misunderstanding how creatine affects natural waste product levels, which is a key topic addressed.

Key Points

Dispelling Kidney Damage Myths: In healthy individuals, scientific studies show that creatine supplementation does not cause kidney damage.
Creatinine vs. Creatine: The harmless increase in serum creatinine levels from supplementation is often mistaken as a sign of kidney harm; it simply reflects increased metabolic turnover.
Liver Safety is Proven: Extensive research has found no evidence that creatine supplementation at recommended doses has a toxic effect on the liver in healthy individuals.
Recommended Dosage is Key: The safety profile is based on recommended doses (3-5g daily). Excessive megadosing is unnecessary and can increase the risk of mild side effects.
Pre-existing Conditions Require Caution: Individuals with pre-existing kidney or liver diseases should not take creatine without first consulting a medical professional.
Purity Matters: To avoid risks from contaminants, always choose a high-quality, reputable creatine monohydrate product.

Creatine: A Primer on Metabolism and Function

Creatine is a naturally occurring compound derived from amino acids and produced primarily in the liver, kidneys, and pancreas. It plays a crucial role in the body's energy production, helping to regenerate adenosine triphosphate (ATP) in muscle cells during high-intensity, short-duration exercise. Approximately 95% of the body's creatine is stored in skeletal muscle. It is also found in foods like red meat and fish, and is one of the most widely studied and effective supplements for improving strength and athletic performance.

The Creatine and Kidney Myth: Creatinine Misinterpretation

One of the most persistent myths is that creatine supplementation is bad for the kidneys. This concern stems from a misunderstanding of how creatine is metabolized. As creatine is used by the body, it is spontaneously converted into a waste product called creatinine. Healthy kidneys filter creatinine from the blood for excretion in urine. When a person takes creatine supplements, their total body creatine pool increases, which naturally leads to a slight elevation in serum creatinine levels.

This elevated creatinine is not a sign of kidney damage in healthy individuals. It simply reflects the higher creatine turnover. For doctors evaluating kidney health, standard creatinine tests can be misleading for someone taking supplements. This is why more advanced tests, like measured glomerular filtration rate (mGFR) or cystatin C, are recommended to get a more accurate picture of kidney function in creatine users. Numerous studies have confirmed that long-term creatine use (up to 5 years) in healthy individuals does not negatively impact renal function.

Factors That Influence Creatinine Levels

Beyond creatine supplementation, several factors can affect serum creatinine, including:

Muscle mass: Individuals with higher muscle mass naturally have higher creatinine levels.
Diet: High protein intake, especially from cooked red meat, can increase creatinine.
Exercise: Intense physical activity can temporarily elevate creatinine levels.
Medications: Some medications, such as certain antibiotics and heartburn drugs, can interfere with creatinine transport in the kidneys.
Hydration: Dehydration can cause a temporary rise in creatinine.

The Creatine and Liver Myth: Understanding Metabolism

Similar to the kidney concern, the fear that creatine harms the liver in healthy individuals is unfounded. While the liver is one of the primary organs that produces creatine endogenously, numerous controlled studies have shown no evidence of liver damage from recommended doses of creatine supplementation. Tests measuring liver function markers like ALT and AST show no significant adverse changes in healthy participants using creatine.

One potential cause for this myth is historical, poorly controlled studies or anecdotal case reports that did not account for other factors, such as the use of other supplements or substances, or pre-existing conditions. Modern, well-designed research has consistently debunked these claims for healthy individuals.

Safety for Specific Populations

While the scientific consensus is clear regarding healthy individuals, specific populations should exercise caution. Individuals with pre-existing liver or kidney diseases are advised to consult a healthcare professional before starting creatine supplementation. In these cases, the increased metabolic load, while harmless for a healthy system, could potentially exacerbate an existing condition. Case studies have shown problems, but often in individuals with underlying issues or those who misused supplements. For everyone, staying well-hydrated is always recommended when taking creatine to support optimal kidney function.

Creatine Myths vs. Scientific Facts


Myth	Scientific Fact
Creatine causes kidney damage.	In healthy individuals, creatine does not cause kidney damage. The slight rise in creatinine is not an indicator of harm.
Creatine harms the liver.	There is no evidence that creatine damages the liver in healthy individuals. Liver function markers remain stable with recommended use.
Creatine causes dehydration and cramps.	Research does not support this claim. In fact, by drawing water into muscle cells, creatine may help with hydration.
All creatine products are the same.	The purity of products varies. Choosing a high-quality creatine monohydrate from a reputable brand is important to avoid contaminants.
Creatine is an anabolic steroid.	Creatine is not a steroid. It is a naturally occurring compound derived from amino acids and works differently than synthetic hormones.
Creatine is only for bodybuilders.	Creatine benefits a wide range of individuals, including athletes, older adults looking to maintain muscle, and those seeking cognitive benefits.

Conclusion

Based on extensive research spanning several decades, the claim that creatine harms the liver or kidneys in healthy individuals is a myth. The misconception regarding kidney health is based on a misinterpretation of creatinine levels, a harmless and expected byproduct of creatine metabolism. Concerns about liver damage are also unfounded, with studies showing no negative effects on liver function markers with standard use. While creatine is widely considered safe and effective, individuals with pre-existing kidney or liver conditions should always consult a healthcare provider before use. For healthy adults, using a high-quality creatine monohydrate at recommended dosages (3-5 grams per day) is an effective and safe strategy for performance and muscle gains.

For more detailed information on creatine's safety and effects, refer to the position stand from the International Society of Sports Nutrition (ISSN), a leading authority on supplement research. ISSN position on creatine

Frequently Asked Questions

Creatine naturally breaks down into creatinine as it is used by the body. Supplementing with creatine increases the body's total creatine pool, which results in more creatinine being produced and detected in the blood.

To get a more accurate assessment, healthcare providers can use methods other than a standard serum creatinine test. These include measuring glomerular filtration rate (GFR) or checking levels of a different biomarker called cystatin C, which is not influenced by muscle mass or creatine intake.

No. The vast majority of studies on healthy individuals show no negative impact on liver function from creatine supplementation at recommended doses. The liver processes creatine, but is not harmed by supplemental intake.

Yes, research indicates that long-term creatine use (studies up to 5 years) at recommended dosages is safe for healthy individuals. No significant adverse effects on the liver or kidneys have been observed.

Individuals with a history of kidney stones or other kidney problems should consult a doctor before using creatine. Although there is no direct evidence that creatine causes kidney stones, a healthcare professional can assess the risk based on your personal health history.

For safety and efficacy, a maintenance dose of 3 to 5 grams of creatine monohydrate per day is typically recommended. Loading phases with higher doses are also considered safe, but they are not necessary for achieving full muscle saturation over time.

Yes, proper hydration is important for overall kidney health, especially while taking creatine. Creatine pulls water into muscle cells, so drinking plenty of fluids is essential to prevent dehydration.