Inspired by recent media coverage and growing public interest, this article explores what creatine actually does in the body, the evidence supporting supplementation, and whether it deserves its reputation as one of the most effective nutritional supplements available today.
Creatine has gone mainstream
Creatine was once regarded as a supplement used primarily by bodybuilders and elite athletes. Today, it is increasingly discussed in relation to healthy ageing, cognitive function, muscle preservation, recovery and metabolic health. Recent coverage featuring NHS GP Dr Amir Khan highlighted creatine's role in cellular energy production and its potential value alongside resistance training.
Unlike many supplements whose claims exceed the evidence, creatine is unusual. It is one of the most extensively studied dietary supplements in the world, with hundreds of clinical trials evaluating its efficacy and safety. The question is no longer whether creatine works, but rather who may benefit most and under what circumstances.1
What is creatine?
Creatine is a naturally occurring nitrogen-containing compound synthesised primarily in the liver, kidneys and pancreas from three amino acids:
- Arginine
- Glycine
- Methionine
Approximately half of our daily creatine requirement is produced internally, while the remainder comes from dietary sources, particularly:
- Red meat
- Fish
- Seafood
Once synthesised or consumed, around 95% of creatine is stored in skeletal muscle, where it exists as either free creatine or phosphocreatine. Smaller amounts are stored in the brain, heart and other tissues.1
The biochemistry: why creatine matters
To understand creatine, we need to understand ATP.
ATP (adenosine triphosphate) is the body's universal energy currency. Every muscle contraction, nerve impulse and cellular process requires ATP. When energy is needed:
ATP → ADP + Phosphate + Energy
Once ATP loses a phosphate group it becomes ADP (adenosine diphosphate). The challenge is that ATP stores within muscle are tiny and can only sustain maximal effort for a few seconds. This is where phosphocreatine becomes essential.
Phosphocreatine + ADP → ATP + Creatine
The enzyme creatine kinase rapidly transfers a phosphate group from phosphocreatine back to ADP, regenerating ATP. This system is particularly important during:
- Sprinting
- Weightlifting
- Jumping
- High-intensity interval training
- Explosive sports performance
Essentially, phosphocreatine acts as an emergency energy reservoir that helps maintain ATP levels during intense energy demand.1
Does supplementation increase muscle creatine stores?
Yes. Numerous studies have demonstrated that creatine monohydrate supplementation increases intramuscular creatine and phosphocreatine concentrations by approximately 10–40%, depending on baseline levels and dietary habits. Vegetarians often experience greater increases because they start with lower muscle creatine stores.1
By increasing phosphocreatine availability, muscles can regenerate ATP more rapidly between efforts. This leads to:
- Higher training volume
- Increased power output
- Better recovery between sets
- Greater long-term training adaptations
Does creatine actually build muscle?
The evidence is remarkably strong. A 2024 systematic review and meta-analysis examining adults under 50 years old found that creatine supplementation combined with resistance training significantly improved both upper- and lower-body strength compared with placebo.2
A more recent meta-analysis similarly concluded that creatine supplementation significantly improves muscle strength, particularly when combined with high-intensity resistance exercise.3
Importantly, creatine is not an anabolic steroid. It does not directly stimulate muscle growth. Instead it enhances training quality, enabling:
- More repetitions
- Heavier loads
- Greater mechanical tension
- Improved recovery
Over weeks and months these adaptations contribute to increased lean muscle mass and strength.1,2 The strongest evidence therefore supports creatine + resistance training rather than creatine alone.2,8
Creatine and healthy ageing
One of the most exciting areas of research concerns ageing. Beginning in middle age, adults gradually lose muscle mass and strength through a process known as sarcopenia. Loss of muscle contributes to:
- Falls
- Frailty
- Reduced mobility
- Loss of independence
- Increased mortality
Several meta-analyses suggest that creatine supplementation combined with resistance training produces modest but meaningful improvements in muscle strength in older adults.7,8
Because ageing is associated with reduced muscle mass, reduced physical activity and potentially lower dietary creatine intake, supplementation may help preserve functional performance when combined with exercise programmes.1,7
For a company like Chxhealth, this is particularly relevant because maintaining muscle mass is increasingly recognised as a key marker of healthy ageing.
What about cognitive function?
The brain is another energy-hungry organ. Like muscle, neural tissue uses ATP continuously. Emerging evidence suggests creatine may support cognitive performance by improving cellular energy availability in the brain.
A 2024 meta-analysis found positive effects on memory, attention and processing speed, although the evidence remains less convincing than that for exercise performance.5 Similarly, a 2025 systematic review of older adults concluded that creatine may support memory and attention, but further high-quality trials are needed before firm recommendations can be made.4
Current evidence supports a cautious conclusion: the muscle benefits of creatine are well-established; the brain benefits remain promising but not yet definitive.4,5
Is creatine safe?
This question has generated debate for decades. The short answer is: for healthy individuals, current evidence overwhelmingly indicates that creatine monohydrate is safe. The International Society of Sports Nutrition has stated that both short- and long-term supplementation is safe and well tolerated, with studies demonstrating safety at doses up to 30 g/day for several years.1
What about kidney damage?
This remains one of the most persistent myths. Creatine can increase blood creatinine levels because creatinine is a normal breakdown product of creatine metabolism. However, an elevated creatinine result does not automatically mean kidney damage.
A 2025 systematic review examining kidney outcomes found that creatine supplementation produced only small changes in serum creatinine and no significant adverse effect on glomerular filtration rate (GFR), the more important measure of kidney function.6 That said, people with:
- Chronic kidney disease
- Significant renal impairment
- Complex medical conditions
should discuss supplementation with their healthcare professional before use.6
What is the best dose?
The most evidence-based approaches are:
Option 1: Loading protocol
20 g/day (4 × 5 g doses) for 5–7 days, followed by 3–5 g/day maintenance.
Option 2: Simpler daily use
3–5 g/day continuously, without loading.
Both approaches ultimately achieve muscle saturation, although loading reaches that point faster.1
Chxhealth verdict
Creatine is one of the rare examples where scientific evidence strongly supports the claims. The strongest evidence shows that creatine monohydrate:
- ✅ Increases muscle creatine stores
- ✅ Improves high-intensity exercise performance
- ✅ Increases strength when combined with resistance training
- ✅ Supports lean muscle gains over time
- ✅ May help preserve muscle function during ageing
- ✅ Has a strong safety record in healthy individuals
However:
- ❌ It is not a substitute for exercise
- ❌ It is not a shortcut to muscle growth
- ❌ Evidence for cognitive benefits remains preliminary
- ❌ People with kidney disease should seek medical advice before use
For most healthy adults engaging in resistance training, creatine monohydrate is arguably the best-studied and most effective performance supplement currently available. The science suggests that the real benefit is not simply "more muscle", but improved cellular energy availability. In an ageing population increasingly concerned about maintaining strength, mobility and independence, that may be where creatine's greatest long-term value lies.
Understand your own baseline
Concerned about your results? Chxhealth offers evidence-based testing designed to help you better understand your metabolism, nutrition and overall health. Whether you're experiencing fatigue, reduced athletic performance or simply want a clearer picture of your wellbeing, our laboratory testing and personalised insights can help you make informed decisions about your health. Explore testing with our Athletic Performance Panel.
This article is informational. Chxhealth is a biomarker and genetic data provider. We do not diagnose, treat or prescribe. Creatine is a dietary supplement, not a medicine; if you have a medical condition or take regular medication, speak to a qualified healthcare professional before starting any supplement.
References
- International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. Available here.
- Wang Z, et al. Effects of creatine supplementation and resistance training on muscle strength gains in adults <50 years of age: a systematic review and meta-analysis. Nutrients. 2024. Available here.
- Zhang H, et al. Effects of creatine supplementation on muscle strength gains: a meta-analysis and systematic review. PeerJ. 2025. Available here.
- Marshall S, et al. Creatine and cognition in aging: a systematic review. Nutr Rev. 2025. Available here.
- Xu C, et al. Creatine supplementation and cognitive function: a systematic review and meta-analysis. Front Nutr. 2024. Available here.
- Naeini EK, et al. Effect of creatine supplementation on kidney function: a systematic review and meta-analysis. BMC Nephrol. 2025. Available here.
- Li N. Creatine supplementation and exercise in aging: a narrative review of the muscle–brain axis and its impact on cognitive and physical health. Front Nutr. 2025. Available here.
- Yao L, Yang D, Gao J, et al. Effects of resistance training combined with creatine supplementation on muscle strength, physical function, and muscle mass in older adults: a systematic review and three-level meta-analysis. Front Nutr. 2026;13. Available here.
News coverage that prompted this article: "TV doctor gives verdict on creatine supplements as risks studies published" (MSN).
