Is Creatine Safe? Benefits, Side Effects and Kidney Health

You've probably heard someone at the gym talk about creatine. Maybe you've seen it recommended on TikTok, watched fitness influencers swear by it, or considered taking it yourself to build muscle and improve your workouts.

But here's the thing: Does creatine actually work, and is it safe to take every day?

There are plenty of claims online about what creatine can do. Some people say it helps you get stronger and build muscle faster. Others worry that it causes hair loss, makes you gain fat, or damages your kidneys. And then there's the question almost everyone seems to ask: Should I take it before or after my workout?

With so much information floating around, it can be difficult to separate facts from fitness myths.

So, let's look at what scientific research actually tells us. We'll explore the benefits of creatine, how much you need to take, whether timing matters, and what studies say about its possible side effects, particularly its effects on kidney function.

This isn't about convincing you to buy a supplement. It's about understanding what creatine can realistically do, what the evidence doesn't prove, and whether taking it makes sense for you.

Let's start with the science.

What Is Creatine, and How Does It Work?

Creatine is a naturally occurring compound that your body produces and obtains from foods such as meat and fish. Most of the body's creatine is stored in skeletal muscles.

Its primary role is to help regenerate adenosine triphosphate (ATP), the molecule cells use for energy. During short, intense activities such as lifting weights or sprinting, muscles need energy quickly. Creatine helps replenish ATP by supporting the phosphocreatine energy system.

Taking creatine supplements increases the amount of creatine stored in your muscles. This can help support repeated high-intensity efforts and improve training performance over time.

That is why creatine is particularly useful for people doing resistance training, weightlifting, sprinting, and other activities involving repeated bursts of intense effort. It is not a steroid, and it does not work like a stimulant. Instead, it supports an energy system your muscles already use.

Creatine monohydrate is the most extensively studied form and remains the standard choice for supplementation. There is no convincing evidence that more expensive forms consistently outperform it.^[7][8]

5 Evidence-Based Benefits of Creatine

1. Creatine Can Improve Muscle Strength

One of the best-supported benefits of creatine is improved strength when combined with resistance training. Creatine supplementation helps muscles maintain performance during repeated high-intensity efforts. Over time, this may allow people to complete more repetitions, sustain training quality, or handle a greater training workload.

However, creatine does not automatically make someone stronger simply by taking it. Resistance training remains essential to achieving strength gains.

A 2024 systematic review and meta-analysis published in Nutrients examined 23 studies involving adults younger than 50 years. Compared with placebo, creatine supplementation combined with resistance training was associated with pooled improvements in upper- and lower-body strength. The reported weighted mean differences were 4.43 kg for upper-body strength and 11.35 kg for lower-body strength.^[1]

These are pooled study estimates, not guaranteed gains for an individual. Most participants in the included studies were male, which limits how confidently the findings can be generalized to every population.

The practical takeaway: Creatine can improve the results of a well-designed strength-training program, but individual responses vary.

2. Creatine Can Help Increase Lean Body Mass

Creatine is often associated with muscle growth, but it is important to understand what researchers actually measure.

Studies frequently measure lean body mass or fat-free mass. These measurements include muscle tissue but can also be influenced by body water. An increase in lean mass therefore does not mean every kilogram gained represents newly developed muscle tissue.

A 2024 systematic review and meta-analysis in the Journal of Strength and Conditioning Research examined creatine supplementation alongside resistance training in adults younger than 50 years. Across 12 included studies, creatine supplementation compared with resistance training alone was associated with an additional 1.14 kg of lean body mass, a 0.73 kg reduction in fat mass, and a reduction of 0.88 percentage points in body-fat percentage.^[2]

These were pooled averages, not predictions for individual users. The included studies varied in their methods and had differing levels of risk of bias.

Creatine can support improvements in body composition when combined with resistance training, but it should not be treated as a guaranteed muscle-building shortcut. Progress still depends on consistent training, adequate nutrition, sufficient protein intake, and recovery.

3. Creatine Can Improve Repeated High-Intensity Exercise

Creatine is especially useful for exercise that requires short bursts of intense effort. Examples include weightlifting, repeated sprints, and activities that involve high-intensity efforts separated by short recovery periods.

The explanation is relatively straightforward: increasing muscle creatine stores helps support rapid ATP regeneration during these activities. The US National Institutes of Health Office of Dietary Supplements identifies improvements in strength, power, and performance during repeated high-intensity exercise as established benefits of creatine supplementation.^[8]

However, creatine is not equally useful for every sport. For continuous endurance activities, such as long-distance running, its benefits are less consistent. In sports where additional body weight is disadvantageous, any increase in body mass may also matter.

Bottom line: Creatine is particularly useful for strength and power training. It is not a universal performance enhancer for every type of exercise.

4. Creatine Can Increase Body Weight Without Increasing Body Fat

One common concern is gaining weight after starting creatine. This can happen, particularly during the early stages of supplementation.

Creatine increases water stored in muscle tissue. As a result, body weight may rise even before meaningful changes in muscle size occur. The US National Institutes of Health Office of Dietary Supplements notes that creatine supplementation can produce weight gain partly through increased water retention. Studies involving strength-training programs have reported increases of approximately 1 to 2 kg in total body weight over a month, although individual responses vary.^[8]

This increase should not automatically be interpreted as fat gain. It is useful to distinguish water weight, lean mass, and fat mass. Creatine is not a fat-burning supplement, although it may support improvements in body composition when combined with resistance training.

If your weight increases after starting creatine, consider your strength, measurements, training progress, and longer-term body-composition changes rather than relying on the scale alone.

5. Creatine May Support Better Training Adaptations Over Time

Creatine's benefits are not limited to what happens during one workout. By supporting repeated high-intensity efforts, creatine can help people maintain the quality of their training sessions. Across weeks of consistent resistance training, this may contribute to improvements in strength and lean body mass.^[7][8]

However, the supplement should be viewed as one component of a broader training program. Creatine cannot replace adequate nutrition, progressive resistance training, sleep, or recovery. It also does not guarantee faster progress for everyone. Responses vary with factors such as starting muscle creatine levels, dietary intake, and training program.

What Is the Recommended Creatine Dosage?

For most healthy adults interested in improving strength and exercise performance, 3 to 5 grams of creatine monohydrate per day is a commonly used maintenance dose.^[7][8]

Option 1: Take 3 to 5 Grams Every Day

This is the simpler approach. Take 3 to 5 grams daily, including days when you do not exercise. You do not need to increase the dose just because you are training more frequently.

Without a loading phase, it generally takes approximately three to four weeks of consistent supplementation to substantially increase muscle creatine stores.^[7] This approach avoids the need to consume larger amounts during the first week.

Option 2: Use a Loading Phase

A loading phase increases muscle creatine stores more quickly. A commonly studied protocol is:

Phase	Daily dosage	Duration
Loading	Approximately 20 g, divided into four 5 g doses	5 to 7 days
Maintenance	3 to 5 g	Daily thereafter

An alternative weight-based loading protocol uses approximately 0.3 g/kg/day for five to seven days before transitioning to maintenance dosing.^[7][8]

The loading phase is optional. It is not necessary to obtain benefits from creatine. Because larger doses may increase gastrointestinal discomfort, dividing a loading dose throughout the day is preferable to taking the entire amount at once.

For most beginners: Taking 3 to 5 grams daily is a straightforward approach. There is no need to take excessive amounts in the belief that more creatine will automatically produce better results.

What Is the Best Time to Take Creatine?

Should you take creatine before your workout, immediately afterward, or at bedtime? This is one of the most frequently asked questions about creatine supplementation.

The available research does not establish a clear, universally superior time.

A randomized, double-blind, placebo-controlled study published in Frontiers in Sports and Active Living in 2022 examined creatine timing in 34 healthy, resistance-trained collegiate athletes. Participants consumed placebo, 5 grams of creatine within an hour before training, or 5 grams within an hour after training over an eight-week resistance-training period. The researchers found that timing did not exert an additional influence on the measured outcomes.^[3]

The study was small, so it cannot rule out every possible difference, but its findings do not support the claim that precise workout timing is essential.

You can take creatine in the morning with breakfast, before your workout, after your workout, or with another meal at a time that suits your routine. Taking it with food may be more comfortable for people who experience stomach discomfort.

Should You Take Creatine Before or After a Workout?

Either is reasonable. Some studies have suggested potential advantages to taking creatine close to exercise, but the evidence is not strong enough to establish a clear winner. For most people, taking the recommended daily dose consistently is more important than worrying about whether it was consumed 30 minutes before or after training.^[3][7]

Should You Take Creatine on Rest Days?

Yes. If you are following a daily supplementation routine, continue taking creatine on rest days. The purpose of daily supplementation is to maintain elevated muscle creatine stores, not simply to provide a dose on the days you exercise.^[7]

Does Creatine Affect Kidney Function?

This deserves a careful discussion because the answer is more nuanced than a simple yes or no.

Creatine supplementation can increase serum creatinine, a blood marker commonly used to assess kidney function. However, an increase in serum creatinine does not necessarily mean the kidneys have been damaged.

Creatine vs. Creatinine: What Is the Difference?

Creatine is a compound involved in energy production. Creatinine is a waste product generated partly through the normal breakdown of creatine and phosphocreatine. The kidneys help eliminate creatinine from the blood.

Clinicians commonly use serum creatinine to estimate the glomerular filtration rate, or eGFR, which provides an estimate of how effectively the kidneys filter blood. However, serum creatinine is not influenced exclusively by kidney function. Creatine supplementation can increase the amount of creatine available for conversion into creatinine.

Consequently, a person taking creatine may experience an increase in serum creatinine even when the kidneys are functioning normally. Because many eGFR equations use serum creatinine, this increase can also make creatinine-based eGFR appear lower.

This is an important interpretive issue, but it should not be used to dismiss every abnormal kidney-function result. An increase in creatinine can also occur with genuine kidney dysfunction, so the clinical context matters.^[4][5]

What Do the Recent Studies Say About Creatine and the Kidneys?

Two systematic reviews and meta-analyses published in 2026 provide useful evidence. Their findings are broadly reassuring about several kidney markers, but they do not say exactly the same thing about all estimates of kidney function.

Study 1: Tsiaras et al. (2026)

Published in the Journal of Renal Nutrition, this systematic review and meta-analysis included 19 randomized controlled trials and one randomized crossover study. The researchers reported that creatine supplementation was associated with an average increase in serum creatinine of 0.13 mg/dL compared with control conditions. They found no statistically significant differences in blood urea or eGFR between the creatine and control groups. The authors called for longer-term randomized trials extending beyond one year.^[4]

Study 2: de Souza Almeida et al. (2026)

Published in International Urology and Nephrology, this systematic review and meta-analysis included 26 studies involving 1,036 participants. The researchers found that creatine supplementation was associated with an increase in serum creatinine averaging 0.14 mg/dL. They also found a reduction in glomerular filtration rate when it was estimated using creatinine-based methods.

However, the review found no statistically significant differences in glomerular filtration rate measured using chromium-51 EDTA, an exogenous filtration marker, or in serum urea, albuminuria, and proteinuria. The authors suggested that the rise in serum creatinine may reflect altered creatinine metabolism rather than kidney injury, while the different findings from different measurement methods warrant careful interpretation.^[5]

So, Does Creatine Damage the Kidneys?

For otherwise healthy adults using conventional doses, current evidence does not establish that creatine monohydrate causes kidney damage. However, this conclusion requires qualifications.

First, studies have not all used the same methods for assessing kidney function. Creatinine-based eGFR can be difficult to interpret during supplementation, whereas directly measured filtration markers provide different information.

Second, many trials have relatively limited follow-up. More research is needed to characterize the effects of very long-term supplementation. Third, findings in healthy adults should not automatically be applied to everyone with pre-existing kidney disease.

People with chronic kidney disease, reduced kidney function, a kidney transplant, or an unexplained abnormal kidney-function test should consult their healthcare professional before taking creatine. The same applies to people taking medications that may affect kidney function or who have other significant medical concerns.

What If Your Creatinine Level Increases While Taking Creatine?

Tell your healthcare professional that you are taking creatine, including the dose and how long you have been using it. Do not assume that an elevated result is harmless, but do not automatically interpret it as proof of kidney damage either.

Depending on the clinical situation, your healthcare professional may consider your previous results, repeat testing, urine albumin measurements, cystatin C, or other methods of assessing kidney function. Cystatin C can be useful because it is not generated through the same creatine-to-creatinine pathway. However, it also has limitations, and no single test should be interpreted in isolation.

The key point: Creatine supplementation belongs in the clinical history when interpreting kidney-function tests.^[4][5]

Creatine Side Effects: What Should You Know?

Creatine monohydrate has a substantial research history, and studies generally support its tolerability in healthy adults when used at recommended doses. Nevertheless, side effects can occur.

1. Weight Gain

Water retention within muscle tissue is a recognized effect of creatine supplementation. Some people notice an increase in body weight, particularly when they begin supplementation or use a loading phase. This does not automatically mean they have gained body fat.^[8]

2. Gastrointestinal Discomfort

Some users experience nausea, diarrhea, bloating, or stomach discomfort. Larger individual doses may be more difficult to tolerate. Taking a maintenance dose of 3 to 5 grams daily, splitting larger loading doses, and taking creatine with food if needed may help.^[7][8]

3. Dehydration and Muscle Cramps

Creatine is often blamed for dehydration and muscle cramps. However, controlled research has not established that creatine supplementation at recommended doses consistently causes dehydration or impairs the body's ability to regulate temperature during exercise.^[9]

That does not mean hydration is unimportant. Fluid needs still depend on activity, environmental temperature, sweating, and individual circumstances. Drink appropriately for your activity and conditions rather than deliberately restricting fluids or forcing excessive amounts of water.

4. Kidney-Function Test Changes

As discussed above, creatine can increase serum creatinine and affect creatinine-based estimates of kidney function. This does not automatically mean kidney injury, but abnormal results still require appropriate interpretation. People with established kidney disease should seek individualized advice before supplementing.^[4][5]

5. Hair Loss

The concern that creatine causes hair loss partly arose from earlier research examining dihydrotestosterone, or DHT, a hormone involved in androgen-related hair loss. However, an association between a hormone and hair loss does not establish that creatine supplementation causes hair loss.

A randomized controlled trial published in 2025 examined 12 weeks of creatine supplementation in healthy, resistance-trained males. Thirty-eight participants completed the study. Researchers found no significant differences between the creatine and placebo groups in DHT levels, other measured hormonal outcomes, or the assessed hair-growth parameters.^[6]

This is reassuring, but it is not definitive proof that creatine could never influence hair loss in any individual. The trial was relatively small and lasted only 12 weeks. For now, the available evidence does not support the claim that creatine supplementation routinely causes hair loss.

What Does the Peer-Reviewed Research Actually Show?

The studies discussed above provide a clearer picture when their findings are considered together.

Study	Type of research	Main findings	Important limitation
Wang et al. (2024) [1]	Systematic review and meta-analysis of 23 studies	Creatine combined with resistance training improved pooled upper- and lower-body strength outcomes.	The included studies were predominantly male.
Desai et al. (2024) [2]	Systematic review and meta-analysis of 12 studies	Compared with resistance training alone, creatine plus training was associated with 1.14 kg more lean body mass, 0.73 kg less fat mass, and a 0.88-percentage-point reduction in body-fat percentage.	Lean body mass includes water, and individual outcomes vary.
Dinan et al. (2022) [3]	Randomized controlled trial involving 34 athletes	No additional benefit was established for taking creatine before rather than after workouts for the measured outcomes.	Small sample and limited study duration.
Tsiaras et al. (2026) [4]	Systematic review and meta-analysis of 20 randomized studies	Serum creatinine increased by an average of 0.13 mg/dL, without statistically significant differences in blood urea or eGFR.	Longer-term randomized trials are needed.
de Souza Almeida et al. (2026) [5]	Systematic review and meta-analysis of 26 studies involving 1,036 participants	Serum creatinine increased and creatinine-based GFR estimates decreased. No significant difference was found in GFR measured using chromium-51 EDTA or in several other kidney markers.	Different kidney assessment methods produced different results, so the findings require careful interpretation.
Lak et al. (2025) [6]	Randomized controlled trial	No significant differences in DHT or measured hair-growth outcomes were found after 12 weeks of supplementation.	Small sample and limited duration.

Taken together, the evidence supports several conclusions. Creatine has well-established benefits for strength and repeated high-intensity exercise, especially when combined with resistance training. Its effects on body composition are also supported by meta-analyses, although increases in lean mass should not be equated entirely with new muscle tissue.

The evidence does not establish that taking creatine at a particular time before or after exercise produces superior results.

Regarding kidney function, creatine can increase serum creatinine and alter creatinine-based estimates of filtration, but this finding is not equivalent to demonstrating kidney damage. Evidence from other kidney-function measurements is reassuring, although longer-term research remains necessary. This distinction matters because good evidence should inform decisions without overstating what researchers have proved.

Frequently Asked Questions About Creatine

1. What is the best time to take creatine?

There is no clearly established best time. You can take it before or after your workout, in the morning, or with a meal. Consistency is more important than precise timing.^[3]

2. How much creatine should I take per day?

For most healthy adults, 3 to 5 grams of creatine monohydrate daily is a commonly used maintenance dose. A loading phase is optional, not mandatory.^[7][8]

3. Does creatine work on the first day?

You should not expect an immediate stimulant-like effect. With a daily dose of 3 to 5 grams and no loading phase, muscle creatine stores generally increase substantially over approximately three to four weeks. A loading phase can accelerate this process. Meaningful improvements in strength and body composition depend on the training program and develop over time.^[7]

4. Should I take creatine on rest days?

Yes. Daily supplementation helps maintain elevated muscle creatine stores, including when you are not exercising.^[7]

5. Does creatine cause kidney damage?

Current evidence does not establish that conventional doses cause kidney damage in otherwise healthy adults. However, creatine can raise serum creatinine, which may affect creatinine-based estimates of kidney function. Long-term evidence has limitations, and people with existing kidney disease should consult their healthcare professional before use.^[4][5]

6. Can creatine increase creatinine without damaging the kidneys?

Yes. Creatine supplementation can increase the amount of creatinine produced through normal metabolism. As a result, serum creatinine may rise without a corresponding reduction in true glomerular filtration. However, an elevated creatinine result should never be dismissed automatically. The cause must be interpreted in the context of the patient's health, medications, supplement use, and other investigations.^[4][5]

7. Does creatine cause weight gain?

It can increase body weight, especially early in supplementation, partly because of increased water storage in muscles. When combined with resistance training, creatine can also support increases in lean body mass over time. An increase in weight does not automatically indicate an increase in body fat.^[2][8]

8. Does creatine cause hair loss?

Available evidence does not establish that creatine causes hair loss. In a 2025 randomized controlled trial, researchers found no significant differences in DHT or measured hair-growth outcomes between creatine and placebo groups after 12 weeks. More research would be needed to establish whether any effects occur over longer periods or in different populations.^[6]

9. Is creatine monohydrate better than other forms of creatine?

Creatine monohydrate is the standard choice because it is extensively studied and has established benefits. Other forms have not demonstrated consistent superiority for improving muscle creatine levels or exercise performance.^[7][8]

10. Do I need to cycle creatine?

There is no established requirement to cycle creatine when using conventional maintenance doses. Many supplementation protocols use daily maintenance dosing. However, people with relevant medical conditions or concerns about long-term use should discuss their circumstances with a healthcare professional.

11. Do I need to drink extra water when taking creatine?

You should maintain adequate hydration based on your activity level, environment, and individual needs. Creatine has not been shown consistently to cause dehydration at recommended doses. There is no need to force excessive amounts of water simply because you take creatine.^[9]

12. Can people with kidney disease take creatine?

People with chronic kidney disease or reduced kidney function should not assume that recommendations for healthy adults automatically apply to them. Because the evidence and clinical circumstances vary, they should consult their nephrologist or other treating healthcare professional before starting supplementation.

Conclusion: Is Creatine Actually Worth Taking?

In simple words, creatine is one of the better-supported supplements for improving strength and helping people get more out of resistance training.

You do not need an expensive formula, a complicated schedule, or a precisely timed dose to use it. For most healthy adults, 3 to 5 grams of creatine monohydrate daily is a practical approach.

Taking it before your workout is fine. Taking it afterward is also fine. Even taking it with breakfast can work. What matters more is taking it consistently and maintaining a good training routine.

As for kidney health, the evidence is reassuring for healthy adults using conventional doses, but it does not justify saying that creatine is risk-free for everyone. An increase in serum creatinine is not automatically kidney damage, yet it still deserves proper clinical interpretation, particularly in people with pre-existing kidney problems.

The bottom line is that creatine can be useful, but it is not magic. It works best as part of a consistent exercise program, alongside adequate nutrition and recovery. And when it comes to kidney health, the sensible approach is to understand the evidence rather than rely on either internet scare stories or blanket claims that the supplement is completely harmless.

Disclaimer: This article is for educational purposes and does not replace individualized medical advice, diagnosis, or treatment.

References

The numbered citations in the article link to the corresponding references below. DOI links open the publisher's article pages. Use the arrow beside each reference to return to the top of the article.

1. Wang, Z., Qiu, B., Li, R., Han, Y., Petersen, C., Liu, S., Zhang, Y., Liu, C., Candow, D. G., & Del Coso, J. (2024). Effects of creatine supplementation and resistance training on muscle strength gains in adults under 50 years of age: A systematic review and meta-analysis. Nutrients, 16(21), 3665. https://doi.org/10.3390/nu16213665 ↑ Back to article
2. Desai, I., Wewege, M. A., Jones, M. D., Clifford, B. K., Pandit, A., Kaakoush, N. O., Simar, D., & Hagstrom, A. D. (2024). The effect of creatine supplementation on resistance training-based changes to body composition: A systematic review and meta-analysis. Journal of Strength and Conditioning Research, 38(10), 1813–1821. https://doi.org/10.1519/JSC.0000000000004862 ↑ Back to article
3. Dinan, N. E., Hagele, A. M., Jagim, A. R., Miller, M. G., & Kerksick, C. M. (2022). Effects of creatine monohydrate timing on resistance training adaptations and body composition after 8 weeks in male and female collegiate athletes. Frontiers in Sports and Active Living, 4, 1033842. https://doi.org/10.3389/fspor.2022.1033842 ↑ Back to article
4. Tsiaras, A., Loufopoulos, G., Theodoridis, X., Liakopoulos, V., Poulia, K. A., & Chourdakis, M. (2026). The effect of creatine supplementation on kidney function: A systematic review and meta-analysis of randomized controlled trials. Journal of Renal Nutrition. Published online April 24, 2026. https://doi.org/10.1053/j.jrn.2026.04.010 ↑ Back to article
5. de Souza Almeida, A., Dias da Silva, L. O., Takahasi, B. N. A., et al. (2026). Impact of creatine supplementation on kidney health: A systematic review and meta-analysis. International Urology and Nephrology. Published online July 27, 2026. https://doi.org/10.1007/s11255-026-05287-x ↑ Back to article
6. Lak, M., Forbes, S. C., Ashtary-Larky, D., Dadkhahfar, S., Robati, R. M., Nezakati, F., Khajevandi, M., Naseri, S., Gerafiani, A., Haghighat, N., Antonio, J., & Tinsley, G. M. (2025). Does creatine cause hair loss? A 12-week randomized controlled trial. Journal of the International Society of Sports Nutrition, 22(Suppl. 1), 2495229. https://doi.org/10.1080/15502783.2025.2495229 ↑ Back to article
7. Kreider, R. B., Kalman, D. S., Antonio, J., Ziegenfuss, T. N., Wildman, R., Collins, R., Candow, D. G., Kleiner, S. M., Almada, A. L., & Lopez, H. L. (2017). International Society of Sports Nutrition position stand: Safety and efficacy of creatine supplementation in exercise, sport, and medicine. Journal of the International Society of Sports Nutrition, 14, 18. https://doi.org/10.1186/s12970-017-0173-z ↑ Back to article
8. U.S. National Institutes of Health, Office of Dietary Supplements. (n.d.). Dietary supplements for exercise and athletic performance: Fact sheet for health professionals. Open the NIH fact sheet. ↑ Back to article
9. Lopez, R. M., Casa, D. J., McDermott, B. P., Ganio, M. S., Armstrong, L. E., & Maresh, C. M. (2009). Does creatine supplementation hinder exercise heat tolerance or hydration status? A systematic review with meta-analyses. Journal of Athletic Training, 44(2), 215–223. https://doi.org/10.4085/1062-6050-44.2.215 ↑ Back to article