How long before creatine turns to creatinine?

January 13, 2026 •

4 min read

Creatine, a popular and well-researched supplement, plays a vital role in cellular energy production, particularly in muscles. However, in both the body and in supplement form, it can break down into creatinine, a waste product with no ergogenic benefits. This conversion rate varies depending on several factors, including storage conditions and the form of the supplement.

Quick Summary

This guide explains the process of creatine degradation into creatinine, examining the timeline in aqueous solutions versus inside the body. It explores how heat, pH levels, and storage affect the stability of creatine supplements and provides practical advice for maximizing potency and usage.

Key Points

In the Body: 1–2% of the body's total creatine pool naturally converts to creatinine and is excreted daily via the kidneys.
In Dry Powder: Creatine monohydrate is very stable and can last years past its expiration date if stored in a cool, dry place.
In Liquid Solution: Conversion to creatinine begins immediately upon mixing with water. Consume within a few hours for maximum potency.
Acidity and Heat: Both lower pH (acidity) and higher temperatures speed up the conversion of creatine to creatinine.
Supplement Forms: Creatine monohydrate is the most stable form. Liquid and other modified creatines are much less stable.
High-quality Supplements: The presence of creatinine in dry powder can indicate poor product quality or storage.

The Creatine-Creatinine Conversion Process

Creatine is a nitrogenous organic acid that helps supply energy to cells, primarily muscle cells, for quick, high-intensity muscle contractions. It is endogenously synthesized in the kidneys and liver but can also be obtained from food sources, like red meat, and dietary supplements. Once creatine is used in muscle tissue to form adenosine triphosphate (ATP), a fraction of it is converted into creatinine through a non-enzymatic dehydration process. Creatinine is a waste product that the kidneys then filter and excrete through urine. This conversion is a continuous and natural part of the body's metabolism, occurring at a relatively constant rate of 1–2% of the total creatine pool per day.

Creatine Stability in Aqueous Solutions

The timing of creatine's conversion to creatinine is most critical when the supplement is mixed with liquid. Unlike its stability in a dry, powder form, creatine is not stable when dissolved in water due to an intramolecular cyclization reaction.

Room Temperature (approx. 25°C): At room temperature and a neutral pH (6.5–7.5), creatine remains relatively stable for a few hours. However, its degradation accelerates significantly over time. Some studies suggest the half-life of creatine dissolved in water at room temperature can be as short as 12 hours. For this reason, experts recommend consuming a creatine solution shortly after mixing.
Acidity and Temperature: The rate of degradation is highly dependent on both temperature and pH. The lower the pH (more acidic) and the higher the temperature, the faster the conversion to creatinine occurs. This is why mixing creatine with acidic beverages like orange juice or lemonade and letting it sit for days can lead to a significant loss of potency.
High Temperatures: Mixing creatine with very hot water (above 60°C or 140°F) can accelerate its breakdown into creatinine. For best results, use lukewarm water to help dissolve the powder more easily without risking rapid degradation.

Factors Influencing Creatine's Breakdown

Several key factors influence the rate at which creatine converts to creatinine, affecting its potency and storage stability.

Environmental Temperature: Higher temperatures, both in storage and when mixed with liquids, significantly increase the rate of creatine's degradation. Proper storage in a cool, dry place away from direct sunlight is crucial for maintaining the supplement's shelf life.
pH Level: As noted previously, acidity is a major catalyst for the conversion. The degradation of creatine is fastest in acidic environments, while more neutral or alkaline conditions slow the process. For this reason, liquid creatine products, which are often unstable, degrade much faster than powdered creatine monohydrate.
Moisture Exposure: Dry creatine monohydrate powder is exceptionally stable. However, exposure to moisture can cause the powder to clump and begin the degradation process. Ensure supplement containers are sealed tightly to prevent this.
Creatine Form: Creatine monohydrate is known for its stability. Other forms, such as creatine ethyl ester or liquid creatines, are significantly less stable and break down more rapidly. This instability compromises their effectiveness, a key consideration for consumers choosing a supplement.

Proper Creatine Supplementation and Storage

To ensure you are getting the most out of your creatine supplement, it's important to follow best practices for usage and storage. Since creatine is best consumed immediately after mixing, pre-mixing for more than a few hours, or overnight, is not recommended.

Mix Fresh: Always mix your creatine powder fresh before each use. This prevents any significant degradation in the liquid and ensures maximum potency.
Use Proper Temperature: While lukewarm water can help dissolve the powder, avoid using hot liquids, which can accelerate the breakdown to creatinine.
Check Storage Conditions: Keep your creatine container in a cool, dry place away from direct heat and moisture. A kitchen cabinet is a much better choice than a steamy bathroom or a sun-drenched windowsill.
Consider Stability: Creatine monohydrate is the most stable form. Be cautious with other forms, especially liquid or pre-mixed versions, as their stability is much lower.

Comparison of Creatine Forms and Stability


Feature	Creatine Monohydrate	Liquid Creatine	Creatine Ethyl Ester (CEE)
Stability	Highly stable in powder form. Can last several years beyond its expiration date if stored correctly.	Unstable and degrades into creatinine rapidly once mixed or bottled. Short shelf life.	Less stable than monohydrate; breaks down into creatinine more readily in solution.
Conversion Rate	Slow conversion in dry form. Conversion accelerates in liquid, especially with heat and low pH.	High conversion rate due to being in a constant aqueous state. Potency can be significantly lost before consumption.	Higher conversion to creatinine compared to monohydrate, especially in liquids.
Best Practice	Mix fresh with water or a non-acidic beverage just before consumption.	Avoid entirely due to poor stability and potential loss of effectiveness.	Avoid due to chemical instability and unreliable efficacy compared to monohydrate.

Conclusion

The breakdown of creatine into creatinine is an inevitable metabolic process within the body, with a consistent 1–2% conversion rate daily. For supplementation, however, the timing and conditions are far more critical. In a dry powder state, creatine monohydrate is highly stable and can maintain potency for years. Once mixed into a liquid, particularly an acidic or warm one, the conversion process begins immediately and accelerates. To maximize the effectiveness of your supplement, consume it soon after mixing, store it properly, and choose the highly stable creatine monohydrate form over less reliable liquid or modified versions. Understanding this conversion helps ensure that you are getting the full benefits from your supplement rather than ingesting a waste product.

Frequently Asked Questions

If mixed into a liquid and left overnight, creatine will have degraded into creatinine, especially at room temperature. It is best to mix your creatine supplement immediately before consumption to ensure maximum potency.

Yes, creatine loses potency over time in a solution. The conversion rate to the inactive waste product, creatinine, increases with time and exposure to factors like heat and acidity. For this reason, consuming a creatine solution promptly after mixing is the best practice.

While it is generally not harmful to ingest a creatine solution that has sat for a long time, its effectiveness will be significantly reduced as it has converted to creatinine. There is little benefit to consuming a degraded supplement.

Creatine monohydrate powder is the most stable form of creatine. In dry conditions, it is highly resistant to breaking down into creatinine and has a long shelf life. Other forms, particularly liquids, are significantly less stable.

Temperature significantly impacts creatine's stability, with higher temperatures increasing the rate of conversion to creatinine. Creatine stored in a cool, dry place will last much longer than creatine exposed to heat.

Mixing creatine in orange juice is not ideal for long-term storage, as the juice's acidity will accelerate the creatine-to-creatinine conversion. While consuming it immediately is fine, plain water is a safer mixing option if you cannot drink it right away.

Properly stored creatine monohydrate is likely to remain effective for several years past its expiration date. However, if it has been exposed to moisture or stored improperly, it may have lost potency. If you have concerns, replacing it is best for peace of mind.