Amino acids & related compounds / Energy metabolism
Creatine
A well-studied training aid. A more careful look beyond the gym.
Creatine helps cells replenish ATP, the energy currency used during muscular work. Its clearest supplement evidence concerns repeated, brief, high-intensity effort. Claims about memory, aging, and everyday energy deserve a separate look at the people and outcomes studied.1
Research prepared 2026-09-14. Clinical review pending.
overview
An energy buffer, not a stimulant
The body produces creatine and stores much of it in muscle. Creatine and phosphocreatine help replenish ATP when muscular demand rises quickly. That mechanism fits repeated sprints or lifting sets; it does not establish unlimited all-day energy.1
Start by identifying the intended outcome: another repetition, greater strength over a training block, or improvement in a specific cognitive task. Evidence for one does not establish the others.
foods
What food contributes
Meat and fish contain creatine; a plant-based eating pattern supplies very little preformed creatine. This does not mean a vegetarian diet causes a creatine deficiency disease. The body also synthesizes it. Food intake and baseline muscle stores can influence a response to supplementation.2
A supplement study using several grams daily is not a direct comparison of two ordinary meals. Keep your overall eating pattern and protein needs in view when interpreting performance claims.
amounts
Loading is a schedule, not a requirement
Research commonly uses either a brief loading phase, about 20 g/day divided into four doses for 5–7 days, followed by 3–5 g/day, or a smaller daily amount without loading. The latter raises muscle stores more gradually, usually over several weeks. These describe research protocols for adults, not a personal recommendation.2
If you and your clinician choose a regimen, decide how you will assess it. Record training performance and tolerance as well as weight. An early change on the scale is not a direct measurement of newly built muscle.
supplements
Compare the ingredient, not the marketing name
Creatine monohydrate has the largest evidence base. More expensive forms have not established consistent superiority for the performance outcomes that matter. Check grams per serving and the number of scoops or capsules required, especially when creatine appears in a multi-ingredient blend.1
Creatine monohydrate
The reference form for most performance research. Micronized describes particle size, not a different clinical outcome.2
Hydrochloride, buffered, or ester forms
Alternative formulations need their own comparative evidence. A smaller advertised serving does not demonstrate equivalence to a studied monohydrate regimen.1
Combination powders and gummies
Use the labeled creatine amount per complete serving for comparison. Caffeine, sweeteners, and other ingredients add separate considerations.
evidence
Which outcome are we talking about?
Use the questions below to separate an established sports application from newer, less certain uses. A positive average result is not a guarantee for every person.
Does creatine help build strength or muscle?
Strongest fit: repeated high-intensity effort with training
The broader sports literature supports improved capacity for repeated high-intensity exercise. The magnitude varies with the person and program.1 A useful distinction is the ability to train versus the amount of muscle gained.
In a 2025 randomized study of 63 adults, 5 g/day increased measured lean mass during a one-week period before training. After that period, both groups gained about 2 kg over 12 weeks of resistance training, without a significant between-group difference. The control group received neither creatine nor placebo. This study highlights how early water-related changes can affect lean-mass measurements; it does not erase the wider performance evidence.3
Will it improve memory or brain fog?
Possible small effects; broad promises run ahead of the data
A preregistered crossover trial tested 5 g/day for six weeks in 123 adults, about half vegetarian. Its statistical analyses supported, at most, a small cognitive benefit. The study tested specific tasks, not resolution of unexplained brain fog or prevention of dementia.4
A task score, day-to-day functioning, and disease prevention are different outcomes. If a product promises all three, ask for separate human evidence for each.
Does a higher creatinine value prove kidney injury?
A result that needs context
The 2026 review included 20 randomized studies and found a modest average increase in serum creatinine. It did not detect a significant change in estimated filtration. Small and short studies still limit what this can establish about long-term use and pre-existing kidney disease.5
testing
Why your clinician should know you take it
Creatine can raise serum creatinine, a breakdown product used in many kidney-function estimates. A 2026 meta-analysis found an average creatinine increase but no statistically significant difference in estimated filtration or urea. The authors called for more trials lasting beyond a year.5
Tell the ordering clinician the product, daily amount, and duration before bloodwork. Do not dismiss an abnormal result as “just creatine.” Kidney assessment still depends on symptoms, trends, medical history, and the tests selected by the clinician.5
safety
Put kidney history and tolerance in context
Healthy-adult research is generally reassuring at studied regimens. It does not establish unrestricted use in people with kidney disease, during pregnancy, or in children. The sports-nutrition literature is extensive, but some authors disclose supplement-industry relationships, and evidence in one population should not automatically be transferred to another.2
Water-related weight gain and digestive discomfort are relevant practical considerations.1 Bring your full supplement and medication list to your clinician if kidney function is impaired or being investigated. More powder is not a substitute for resolving unexplained fatigue or declining exercise capacity.
decisions
Make a useful comparison
Before buying, write down the exact benefit you want, the training or rehabilitation plan accompanying it, the cost per actual serving, and what would make you stop. For strength goals, compare progress over a defined training period. For a memory concern, seek an assessment rather than assuming that sports-performance evidence answers the question.
Questions people ask
Do I have to load creatine?
No. Studies also use smaller daily amounts without a loading phase. The main difference is how quickly stores increase.2
Is early weight gain all muscle?
No. Creatine can change body water, and lean-mass measurements include water. Training outcomes and the timing of the measurement matter.3
Is creatine only for men?
No. Trials include women. A mixed-sex trial does not automatically answer questions about every life stage, including pregnancy or menopause.3
Can I use it as a protein powder?
Creatine and dietary protein have different roles. Evaluate your food and protein needs separately rather than treating a few grams of creatine as a meal replacement.
Should I stop it before a kidney blood test?
Ask the ordering clinician. Report use rather than changing the regimen or interpreting a result on your own.5
Keep exploring
Put the information in context.
Bring your food habits, supplement questions, and goals into a conversation with the Nuvitru team.
Explore nutrition care ↗Sources & further reading
Sources support specific statements, not a blanket endorsement of supplementation.
- NIH Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Health Professional Fact Sheet. Creatine section.
- Kreider RB et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. 2017. Expert synthesis.
- The Effect of Creatine Supplementation on Lean Body Mass with and Without Resistance Training. Nutrients. 2025;17:1081. Randomized trial, 63 adults.
- Sandkühler JF et al. The effects of creatine supplementation on cognitive performance: a randomised controlled study. BMC Medicine. 2023;21:440.
- The effect of creatine supplementation on kidney function: a systematic review and meta-analysis of randomized controlled trials. Journal of Renal Nutrition. Published April 24, 2026.