Creatine monohydrate is one of the most extensively researched supplements in sports nutrition. Despite this, it continues to be surrounded by persistent misconceptions, particularly around safety, kidney health, hormones, hair loss, and neurological risk.
This article summarises what the current scientific evidence actually supports, where conclusions are being overstated, and what remains unresolved.
What is creatine?
Creatine monohydrate is a legal, well-studied, ergogenic supplement with established benefits for high-intensity performance.
Creatine:
- Is naturally present in foods such as meat and fish
- Is endogenously synthesised in the liver, kidneys, and pancreas
- Plays a critical role in ATP regeneration, supporting rapid energy production during high-demand tasks
Creatine supplementation increases intramuscular phosphocreatine stores, enhancing performance in activities requiring repeated bouts of high-power output.
The traditional maintenance dose is 3–5 g per day. However, in applied sport settings, higher intakes of approximately ~20g per day are often used, particularly where neurological, cognitive, or neuroprotective outcomes are a priority.
Dietary creatine vs supplementation
While creatine is obtained from food, achieving meaningful intakes through diet alone is impractical.
To obtain approximately 10 g of creatine per day from food, intake would need to approximate:
- ~3.4 kg cod
- ~2 kg beef
- Large daily intakes of fish or poultry
From a caloric, financial, and logistical perspective, this is unrealistic for most athletes, making supplementation the most practical approach.
Safety profile and adverse effects
Creatine monohydrate has been classified as Generally Recognised As Safe (GRAS) by the FDA and is the only form of creatine approved for use in food and supplements globally.
A large systematic review and meta-analysis analysed:
- 685 human clinical trials
- 26,038 participants
- Clinical trial data, adverse event reports, and social media sentiment
Across this dataset, 35 categories of side effects were assessed, including gastrointestinal, renal, cardiovascular, neurological, endocrine, and metabolic outcomes.
Key finding
Creatine monohydrate did not increase the incidence of any reported side effect compared with placebo.
Reported adverse events in global registries were extremely rare at approximately 0.00072 percent and were typically:
- Associated with poly-supplement use or medications
- Not reproduced in controlled trials
- Unrelated to creatine’s known mechanisms of action
Performance benefits in sport
The performance benefits of creatine supplementation are well established and include:
- Increased strength and power
- Reduced perceived fatigue
- Increased lean mass
- Improved recovery
- Potential reductions in injury risk
- Enhanced training capacity
These benefits explain its widespread use across elite, professional, and Olympic sport.
Creatine, cognition, and brain energy
Creatine is increasingly recognised for its role in brain energy metabolism.
Because creatine can cross the blood–brain barrier and support ATP availability in neurons, supplementation has been investigated for:
- Cognitive performance
- Neural resilience under stress
- Recovery following neurological insult
A systematic review and meta-analysis examining creatine and cognition reported:
- Memory: significant improvements
- Processing speed: significant improvements
- Executive function: no overall effect, with smaller benefits under high cognitive demand
- Attention: no direct improvement, with possible indirect benefits via improved brain energy availability
Creatine should not be considered a nootropic, but rather a metabolic support agent for high-demand cognitive states.
Creatine, sleep deprivation, and stress
A 2024 study demonstrated that in states of sleep deprivation, fatigue, or stress, a single high dose of creatine of approximately 25–30 g:
- Reversed cognitive impairment
- Improved cognitive performance beyond well-rested baseline levels
The proposed mechanism is rapid restoration of cerebral energy stores, supporting neuronal function under stress.
Creatine and concussion
Early research in animal models and contact-sport athletes suggests creatine may:
- Reduce metabolic disturbances following concussion
- Provide neuroprotective benefits
Although evidence in mild traumatic brain injury remains limited, creatine may serve as a preventive strategy in high-risk populations, including contact-sport athletes and military personnel.
Current applied recommendations for concussion prevention and recovery commonly fall within approximately 10–20 g per day, pending further research to refine protocols.
Creatine and hair loss: where the concern originated
Concerns linking creatine to hair loss originate primarily from a single 2009 study conducted in male rugby players.
In this study:
- Participants consumed 25 g per day for 7 days as a loading phase
- Followed by 5 g per day for 14 days as maintenance
Results showed:
- An increase in DHT (dihydrotestosterone) of approximately 56 percent after one week
- DHT remained approximately 40 percent above baseline at three weeks
What the study did not demonstrate
Several critical points were not acknowledged in how this study has been interpreted:
- DHT levels remained within normal clinical ranges
- Total testosterone did not increase
- Free testosterone was not measured
- The creatine group had lower baseline DHT, exaggerating the relative increase
- The placebo group experienced a slight decrease in DHT
- No cases of hair loss or baldness were reported
- Resistance training alone can elevate DHT
- The study involved a very small sample size (n = 20, with 16 completing the study)
Importantly, no study has directly investigated creatine supplementation and hair loss outcomes.
What does the broader research show?
A 2025 systematic review published in the Journal of the International Society of Sports Nutrition analysed:
- 685 clinical trials
- Adverse event reports
- Media and social sentiment
Hair loss was not reported in any study.
Additionally:
- 12 studies examined creatine doses of 3–25 g per day over 6 days to 12 weeks
- Two studies reported small, clinically insignificant increases in total testosterone
- Ten studies found no change in testosterone
- Five studies measured free testosterone, with no increases observed
Current consensus
Based on the totality of evidence:
- There is no convincing clinical evidence linking creatine supplementation to hair loss
- One small study showed a temporary increase in DHT without hair loss
- No trials have demonstrated a causal relationship between creatine and androgenic alopecia
Until higher-quality evidence emerges, claims that creatine causes hair loss remain unsupported.
Summary
Creatine monohydrate remains one of the most rigorously studied supplements in sport and clinical nutrition.
The evidence supports:
- Strong safety and tolerability
- Meaningful performance benefits
- Emerging roles in cognition and neuroprotection
The evidence does not support:
- Claims of kidney damage in healthy individuals
- Increased incidence of adverse side effects
- A causal link to hair loss
As with any intervention, appropriate dosing, context, and individual assessment matter, but creatine’s reputation is not reflective of the scientific data.
References
- PMID: 35267907
- PMID: 39125311
- PMID: 34366447
- PMID: 12500988
- PMID: 40198156
- PMID: 40918156
- PMID: 39072054
- PMID: 30202575
- DOI: 10.1080/15502783.2025.2335881
