Creatine: Does It Actually Work?
Meta-analysis verifiedWe earn commissions on products that pass our evidence checks. We earn nothing on products we rate poorly.
What Is Creatine?
Creatine is a natural compound your body makes from amino acids. Your muscles store it as phosphocreatine and use it for quick energy during intense efforts like lifting weights or sprinting.
You get some creatine from meat and fish. But supplementing with creatine monohydrate raises your muscle stores about 20-40% above what food alone provides.
It’s one of the most studied supplements in history. We’re talking about hundreds of randomized controlled trials. The data on creatine is stronger than almost any other supplement you can buy.
We analyzed 3 major meta-analyses covering 228 individual studies. Here’s what the numbers actually show.
The Evidence, Claim by Claim
The sections below break down each major claim with real data from published meta-analyses. Every effect size, confidence interval, and study count comes from peer-reviewed research.
Strength and Power
This is where creatine shines brightest. Kazeminasab et al. (2025) pooled 69 randomized controlled trials with nearly 3,000 participants. The result: creatine significantly improves maximal strength when combined with resistance training.
The effect size (SMD 0.35) is small to medium. In practical terms, that means a few extra reps or a few extra pounds on your lifts. It won’t double your bench press. But it adds up over months of training.
The evidence quality is as good as it gets in nutrition research. 69 RCTs is a massive body of evidence.
Muscle Mass
Pashayee-Khamene et al. (2024) conducted the largest creatine meta-analysis ever. They pooled 143 RCTs with nearly 6,000 participants looking at body composition.
Creatine increases lean body mass (SMD 0.36). It doesn’t reduce fat mass. Total body weight goes up, partly from water retention inside muscle cells.
Here’s the important part: long-term studies using DEXA scans confirm that the gains aren’t just water. Real muscle tissue grows. The water retention happens early and levels off. The muscle growth continues as long as you keep training.
Cognition
This one is newer and less certain. Xu et al. (2024) analyzed 16 RCTs with about 800 participants looking at cognitive outcomes.
Short-term memory improved with a small effect size (SMD 0.30, p = 0.01). That’s statistically significant but modest.
The interesting finding: the effect is stronger in older adults and vegetarians. This makes sense. Your brain uses creatine for energy. People with lower baseline levels (vegetarians don’t get dietary creatine) seem to benefit more.
This claim gets a “maybe” verdict. The data is encouraging, but 16 studies with moderate heterogeneity isn’t enough to call it settled science.
Dosage
How much: 5g per day. That’s it. No need to get fancy.
Loading phase: Optional. You can take 20g per day (split into 4 doses) for 5-7 days to saturate faster. Or just take 5g daily and reach the same levels in 3-4 weeks.
Timing: Doesn’t matter much. Take it whenever you’ll remember. Some research suggests post-workout may be slightly better, but the difference is tiny.
Form: Creatine monohydrate. Don’t waste money on HCl, buffered, or ethyl ester versions. They cost more and don’t work better. Look for Creapure certification for purity.
With food? Not required. Taking it with carbs may slightly improve uptake, but the effect is small.
Who Should Be Careful With Creatine
Creatine is one of the safest supplements available. But a few groups should be cautious.
If you have kidney disease, talk to your doctor first. Creatine is safe for healthy kidneys, but compromised kidneys may not handle the extra load.
Creatine raises creatinine levels on blood tests. This is a known measurement artifact, not kidney damage. Tell your doctor you take creatine before routine bloodwork so they don’t misinterpret the results.
Stay well hydrated. Creatine pulls water into your muscles. Drink enough water throughout the day, especially during exercise.
If you’re taking NSAIDs regularly or any drugs that stress the kidneys, be extra careful about hydration. The combination isn’t dangerous for most people, but don’t ignore it.
The Bottom Line
Creatine is the real deal. It’s one of the few supplements where the evidence is overwhelming.
For strength and muscle, the data is about as strong as it gets. 143 RCTs don’t lie. If you lift weights and want to get stronger or build more muscle, creatine works.
The cognitive benefits are promising but need more research. If you’re older or don’t eat meat, you might notice a mental boost. But don’t buy creatine for brain power alone just yet.
At roughly $0.12 per day, it’s also one of the cheapest supplements that actually does something. Monohydrate is the way to go. Skip the expensive “advanced” forms.
The Evidence, Claim by Claim
Increases strength and power ✓ Works
69 randomized trials with nearly 3,000 people confirm creatine makes you stronger. The effect is small to medium in size but very consistent. It works for bench press, squat, leg press, and other compound lifts.
This is one of the most well-supported claims in sports nutrition. 69 RCTs is a massive evidence base. Moderate heterogeneity means results vary somewhat, but the direction is clear. Creatine improves maximal strength.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = 0.08 | slight asymmetry detected but not statistically significant |
|---|
Builds muscle mass ✓ Works
143 trials with nearly 6,000 people show creatine increases lean body mass. This is the largest creatine meta-analysis ever done. The effect is small to medium. Fat mass doesn't change. Some of the weight gain is water, but real muscle growth happens too.
143 RCTs make this one of the most studied supplement effects in existence. The lean mass gains are real, not just water. DEXA-measured studies confirm actual muscle tissue increases. Body weight goes up more than lean mass alone, so some water retention is part of the picture.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = 0.12 | no significant asymmetry detected in funnel plot |
|---|
Improves cognition ? Maybe
16 trials with about 800 people show creatine may improve short-term memory. The effect is small but statistically significant. It seems to work better for older adults and people who don't eat meat. Vegetarians and vegans may benefit most because their baseline creatine levels are lower.
The evidence is promising but not yet rock-solid. 16 RCTs is decent, but moderate heterogeneity and the prediction interval crossing zero mean some future studies might not find a benefit. The subgroup effects (older adults, vegetarians) are interesting but need more research.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = 0.22 | no significant publication bias detected |
|---|
Reduces exercise fatigue ? Maybe
14 double-blind trials show creatine boosts your power output during repeated sprints. The effect is moderate (delta 0.61). But here's the catch. It doesn't actually slow down how fast you fatigue. You're more powerful across all sprints, but you still lose power at the same rate. For endurance fatigue, a separate meta-analysis of 13 studies found zero benefit.
Strong evidence that creatine improves repeated sprint power. But the fatigue claim is misleading. Creatine raises the ceiling, not the slope. It doesn't reduce endurance fatigue at all. Gets a 'maybe' because the claim as stated is only half true.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | not reported in accessible abstract |
|---|
Speeds exercise recovery ? Maybe
23 trials with 469 people show creatine lowers muscle damage markers (like CK) at 48-90 hours after hard exercise. That sounds good. But it doesn't improve actual recovery outcomes. Muscle strength, soreness, range of motion, and inflammation all showed no significant improvement. And with long-term use, damage markers actually go UP because creatine lets you train harder.
The headline number (SMD -1.09) looks impressive, but it's fragile. Remove one outlier study and it's no longer significant. High heterogeneity (I2=83%) means results vary widely. No effect on soreness, strength recovery, or inflammation. The paradox of higher CK with chronic use is well-documented.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = 0.55 | no significant publication bias detected |
|---|
Reduces depression symptoms ✗ No Evidence
11 trials with 1,093 people were pooled together, but the results are weak. The average improvement equals about 2.2 points on a depression scale. That's below the 3-point threshold doctors consider meaningful. Six of the 11 trials had high risk of bias. The largest trial (n=1,741) studied Parkinson's patients and found nothing. When you correct for publication bias, the effect shrinks further.
GRADE rates this evidence 'very low,' the lowest possible rating. Downgraded for risk of bias, inconsistency, imprecision, and publication bias. The most promising signal comes from one good RCT of creatine added to SSRIs in women (Lyoo 2012). But the overall evidence doesn't support the claim.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | publication bias inflates the apparent benefit |
|---|
Enhances sprint and high-intensity performance ✓ Works
69 randomized trials with nearly 2,000 people show creatine improves sprint and high-intensity performance. Wingate peak power increased by about 48 watts. Vertical jump improved by 1.5 cm. A separate meta-analysis of 14 repeated sprint studies found creatine boosted mean power by a moderate amount (delta 0.61). Males benefit more than females for power outcomes.
Very strong evidence base. 69 RCTs with no significant publication bias. The ISSN calls creatine the most effective ergogenic supplement for high-intensity exercise. This is distinct from the 'strength' claim because it covers anaerobic sprint performance, Wingate tests, and repeated sprint ability specifically.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = 0.07 | no significant publication bias detected |
|---|
Supports bone health ✗ No Evidence
Two meta-analyses and a 2025 editorial all reach the same conclusion. Creatine doesn't improve bone mineral density. The largest trial (200 women, 2 years, double-blind) found zero effect. One study showed creatine slowed bone loss at the femoral neck specifically, but no other trial replicated this. The 2025 Osteoporosis International editorial explicitly states there's insufficient evidence to recommend creatine for osteoporosis.
The evidence is consistently null. When multiple meta-analyses agree that an effect doesn't exist, that's a strong signal. The one positive finding (Chilibeck 2015 femoral neck) hasn't been replicated in larger or longer trials. Creatine may help muscles, but it doesn't help bones.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | not reported |
|---|
Improves blood sugar control ✗ No Evidence
The only meta-analysis (9 studies) found creatine doesn't improve fasting blood sugar or insulin resistance. The one standout trial (Gualano 2011) showed creatine plus exercise lowered HbA1c by 1.1% in type 2 diabetics. But that's a single trial with 25 people. One study in vegetarians actually showed creatine WORSENED glucose handling. The evidence only looks promising when creatine is combined with exercise in diabetics, and even that needs replication.
The meta-analysis is clear. No significant effect on fasting glucose (SMD 0.05) or HOMA-IR (SMD -0.38). The one impressive result (Gualano 2011 HbA1c reduction) is a single small trial. The mechanism via GLUT-4 translocation is biologically plausible but only activates with exercise. Don't take creatine for blood sugar control.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | not reported in publicly accessible abstract |
|---|
Supports heart failure patients ✗ No Evidence
7 small trials with 243 heart failure patients have tested creatine. It's safe. It may improve skeletal muscle strength in the short term. But it doesn't improve the heart itself. Ejection fraction, peak VO2, and exercise capacity showed no benefit in blinded trials. The largest study (70 patients) found creatine added nothing beyond exercise training alone. The best available review is a 2025 conference abstract, not a full published paper.
The evidence is limited and mostly negative for meaningful outcomes. Creatine improves peripheral muscle function (expected from its known mechanism), but heart failure patients need cardiac improvement, not just stronger legs. The largest blinded RCT was null. One recent open-label pilot showed improved 6-minute walk distance, but it had no placebo control. Grade C because no meta-analysis exists and the trial base is tiny.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | not assessed |
|---|
Protects against traumatic brain injury ✗ No Evidence
This is mostly hype right now. Only one human trial exists. It was a small, unblinded pilot study in 39 children with severe TBI in Greece. It showed improvements in cognitive recovery, headaches, and fatigue. But it wasn't placebo-controlled or blinded. The animal data is strong. Creatine given BEFORE brain injury reduces damage by 36-50% in mice and rats. The DoD and IOM have recommended funding adult trials since 2011. As of 2026, those trials still haven't produced results. Two new RCTs are registered but haven't reported.
Grade D because the human evidence is a single open-label pediatric pilot. The animal data is compelling (would be Grade B alone), but animal neuroprotection results have a terrible track record translating to humans. The preventive angle (pre-loading in athletes and military before injury) is the most promising direction, but zero human preventive studies exist. The 2025 DoD paper confirmed no clinical guidelines exist.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | not applicable with single trial |
|---|
Boosts testosterone and DHT ✗ No Evidence
This claim is mostly internet hype. One single study from 2009 (20 rugby players) found creatine loading increased DHT by 56%. That study has never been replicated. 12 other RCTs looked at testosterone after creatine. Ten found nothing. Two found tiny bumps that stayed within normal range. A 2025 RCT specifically designed to test the hair loss claim found zero effect on DHT, testosterone, or actual hair follicle health over 12 weeks. Creatine isn't a testosterone booster.
The van der Merwe 2009 DHT study is the entire foundation of this claim. It had only 20 subjects, baseline DHT was 23% lower in the creatine group (inflating the apparent increase), and no study in 16 years has replicated it. The 2021 ISSN review by Antonio et al. and the 2023 systematic review by Morgado et al. both conclude creatine doesn't boost testosterone. The 2025 Lak et al. RCT was the final nail. Grade D because the claim rests on a single unreplicated study.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | not assessed |
|---|
Improves skin health and reduces wrinkles ✗ No Evidence
All the evidence for creatine and skin is about rubbing creatine cream on your face, not swallowing it. Three clinical studies showed topical creatine formulations reduced wrinkles and improved skin firmness. But every single study used multi-ingredient products (creatine plus folic acid, guarana, CoQ10, or peptides). You can't tell if creatine did anything. Every study was funded by Beiersdorf, the company that owns Nivea. Zero human trials have tested whether the creatine supplement you take for muscles does anything for your skin.
Grade D because there are literally zero RCTs testing oral creatine for skin outcomes. The topical evidence is all industry-funded with multi-ingredient formulations. The in vitro data showing creatine protects fibroblasts and stimulates collagen is interesting but hasn't been tested clinically with oral supplementation. The leap from 'topical creatine in a Nivea cream reduces wrinkles' to 'taking 5g of creatine monohydrate improves your skin' has no evidence behind it.
View full statistical analysis
Publication Bias Assessment
| Egger's Test | z = —, p = — | not assessed |
|---|
Dosage Guide
| Effective Range | 3-5g |
|---|---|
| Optimal Dose | 5g |
| Best Form | Creatine monohydrate |
| Timing | Any time of day, with or without food |
| Time to Effect | Muscle saturation takes 3-4 weeks at 5g/day, or 5-7 days with a loading phase |
| Cycling | No cycling needed. Daily use is safe long-term. |
| Notes | Loading phase (20g/day for 5-7 days) speeds up saturation but isn't required. Monohydrate is the gold standard. Fancy forms like HCl, buffered, or ethyl ester offer no proven advantage. |
Don't Take If
- Pre-existing kidney disease (consult doctor first)
- Rare kidney conditions like polycystic kidney disease
Drug Interactions
| Medication | Risk | Why |
|---|---|---|
| NSAIDs (ibuprofen, naproxen) | low | Both may affect kidney function in susceptible individuals. Stay well hydrated. |
| Nephrotoxic drugs | moderate | Combined kidney load may be a concern. Monitor renal function. |
| Diuretics | low | Creatine promotes water retention. Diuretics promote water loss. May reduce creatine's effectiveness. |
Possible Side Effects
- Water retention and weight gain (1-2 kg typical)
- Mild GI upset if taken on empty stomach at high doses
- Possible muscle cramping in early use (uncommon)
What to Buy
Disclosure: Links below are affiliate links. We earn a commission if you buy. We never recommend products that fail our evidence checks.
Nootropics Depot Creatine Monohydrate
Creapure-certified monohydrate, third-party tested, best value per serving
Thorne Creatine
NSF Certified for Sport, ideal for tested athletes who need clean-sport certification
What to Avoid
Frequently Asked Questions
Does creatine actually build muscle?
Yes. 143 randomized controlled trials with nearly 6,000 people show creatine increases lean body mass. The effect is small to medium (SMD 0.36), but it's real and consistent across studies. Some early weight gain is water, but long-term studies confirm actual muscle tissue growth.
Is creatine safe for your kidneys?
Yes, for healthy people. Dozens of studies lasting up to 5 years show no kidney damage in people with normal kidney function. Creatine does raise creatinine levels (a kidney marker), but that's a measurement artifact, not actual kidney damage. If you have existing kidney disease, talk to your doctor first.
Do you need a loading phase for creatine?
No. Taking 5g per day will fully saturate your muscles in 3-4 weeks. A loading phase of 20g per day for 5-7 days gets you there faster, but it's not required. Some people get stomach issues from loading doses, so starting with 5g daily is fine.
Does creatine help with brain function?
Maybe. 16 trials show a small improvement in short-term memory (SMD 0.30). The effect seems stronger in older adults and vegetarians. Your brain uses creatine for energy just like your muscles do. The evidence is promising but not as strong as the muscle and strength data.
Is creatine monohydrate better than other forms?
Yes. Creatine monohydrate has the most research behind it by far. Fancier forms like creatine HCl, buffered creatine, and creatine ethyl ester have no proven advantage in head-to-head studies. They usually cost more for no extra benefit. Stick with monohydrate.