Creatine: Research on Strength, Cognition & Aging 2026

TL;DR: Creatine monohydrate is among the most thoroughly researched supplements. Studies report effects on maximum strength (+5 to 15 percent) and lean mass (+1 to 2 kg over 4 to 6 weeks) and examine cognition, muscle preservation in menopausal women and aging. Serum creatinine can rise without this alone pointing to kidney damage. Use and therapy should be cleared with a doctor.

This article is for information only and does not replace medical advice. Whether creatine is an option for you, whether it fits your kidney function or your medication, and what amount may apply is something to clarify beforehand with your doctor. This applies especially with kidney disease. The only relevant figure is always the dose set by a physician.

Why Creatine Is Studied Beyond Strength Training

Creatine is one of the most studied supplements in sports nutrition. More than 500 controlled trials and 60 years of research exist, and so far healthy people show a favorable safety profile. The effects on maximum strength and muscle mass are well described. In recent years research has also examined further areas.

Creatine plays a role wherever cells need fast energy. That means muscle, but also brain, heart and nervous system. Newer studies examine cognitive performance, women in menopause, vegetarians and older adults at risk of sarcopenia. How reliable the evidence is differs by area. Whether a supplement is an option in an individual case is a medical decision.

What Creatine Is and Where It Occurs in the Body

Creatine is not a vitamin or hormone. It is an amino acid derivative the body produces from glycine, arginine and methionine. Endogenous production is about 1 to 2 grams per day, mostly in the liver and kidneys. On top of that comes dietary creatine: about 1 g per 250 g of red meat or fish.

Stores and turnover. Around 95 percent of creatine sits in skeletal muscle. An 80 kg person stores about 120 g. Of that, 60 to 70 percent exists as creatine phosphate (phosphocreatine), the rest as free creatine. Each day 1 to 2 grams are converted to creatinine and excreted via the kidneys.

Energy regeneration. Cells use ATP (adenosine triphosphate) as their energy currency. Under fast demand, such as a sprint, a bench press set or peak cognitive effort, ATP is depleted within seconds. Creatine phosphate donates its phosphate group to ADP and instantly regenerates new ATP. More creatine phosphate in the cell means faster energy turnover.

This logic explains why research looks at creatine wherever short, intense energy bursts are needed. Not only in muscle but also in the brain, especially under stress, sleep loss or low baseline stores (vegetarians).

Research: Strength Training

The evidence for strength training is extensive. Creatine monohydrate is among the best-studied supplements there is, and the reported effects on strength and muscle mass are consistent across many trials.

Maximum strength. Studies report a gain of 5 to 15 percent on multi-set strength training over 4 to 12 weeks, especially visible in squat and bench press. The effect appears in beginners and advanced lifters, slightly stronger in beginners.

Lean mass. A gain of 1 to 2 kg over 4 to 6 weeks is reported. Part of this is intracellular water (about 0.5 to 1 kg), the rest is attributed to higher muscle protein synthesis from better training quality.

Set volume. In studies the gain on final repetitions was 15 to 25 percent. Over months this can add up to measurable progression.

Context. According to current research the effects rest on better ATP regeneration between repetitions and depend on baseline status. Anyone who documents their training and supplements can discuss the course with their doctor, for example using the approach in the guide to reviewing supplement routines.

Research: Cognition and the Brain

After muscle, the brain is the second most important creatine target organ. Around 5 percent of body creatine sits there. Effects are described mainly when the brain is under energy stress.

Sleep deprivation. Under sleep deprivation, subjects on creatine stayed more stable on reaction time and mood than on placebo. The systematic review by Avgerinos et al. (2018) summarizes these effects.

Vegetarians. In vegetarians, memory tests and reaction time improved most clearly on creatine. In omnivores, the effects are smaller because baseline levels are higher.

Older adults. In older subjects too, there are signs of better working memory. Effect size is small to moderate.

The clinically relevant takeaway: the largest cognitive effects are reported when baseline conditions are unfavorable, meaning little sleep, little meat or high age. In young, well-rested omnivores the effect is measurable but small.

Research: Women and Menopause

Women on average have 70 to 80 percent of male muscle creatine stores. However, demand per kilogram of muscle is identical. Recent research has focused specifically on women.

Menopause and muscle preservation. In controlled trials, postmenopausal women on creatine plus resistance training had better muscle strength and bone density than the placebo group. The effect was especially visible at the proximal femur.

Bone. Studies describe that the combination of creatine and resistance training may attenuate menopausal bone loss. The proposed mechanism: better training quality leads to stronger mechanical stimuli at the bone, which preserves density.

Mood and depression. Individual studies examine a supportive effect in depression in women, especially in combination with SSRIs. The evidence is limited. Depression belongs under medical care, and creatine is not a substitute for it.

Context. In menopause, further lab values such as ferritin, vitamin D and thyroid are often reviewed by doctors alongside, see understanding blood values.

Research: Aging and Sarcopenia

From age 40, humans lose 0.5 to 1 percent of muscle mass per year. Past 70, the decline accelerates. Sarcopenia is one of the strongest predictors of loss of independence in old age.

Studies. In trials with older subjects, creatine plus resistance training produced larger gains in muscle strength and mass than training alone. Effect sizes were small to moderate but clinically relevant.

Fall risk as context. Background: in adults over 70, falls are the leading cause of hip fractures. Whether creatine plays a role here is not established in the studies cited.

Notes for older adults. The literature names water retention as a possible point. The described effects developed gradually and became measurable after 4 to 8 weeks. Whether creatine is an option for older adults should be cleared with a doctor.

Forms Compared

The market offers many variants for which a benefit over monohydrate has not been shown. The table summarizes the evidence.

Bottom line: Scientifically, monohydrate is the form with the broadest evidence. The literature describes no demonstrated added benefit for the alternatives.

When Medical Review Matters

Whether creatine is an option in an individual case is not a question an article can answer. Kidney function, existing medication, pre-existing conditions and diet all matter. Use, dose and therapy should be cleared with a doctor, and with kidney disease always beforehand.

Side Effects and Creatinine

In studies, side effects are described as rare and mild: stomach upset and, rarely, cramps.

Water retention. A weight gain of 0.5 to 1.5 kg is reported in the first weeks. This is intracellular, inside the muscle and not under the skin. It makes the muscle fuller, not softer.

Creatinine levels. The most important misunderstanding in lab interpretation.

Creatinine is the breakdown product of creatine. When you take in more creatine and have more muscle mass, you produce more creatinine. The table puts the markers in context:

If only creatinine is measured, such a rise can be wrongly read as reduced kidney function. Cystatin C is often named as a complementary kidney marker during creatine use, because it is measured independently of muscle metabolism. The eGFR calculated from cystatin C (instead of creatinine) can then give a more accurate picture of kidney function. Which lab values make sense is for the doctor to decide.

If you use creatine, tell your doctor. Documenting use and results can ease interpretation and avoid unnecessary diagnostics. For a systematic overview of putting lab values in context, see the guide on liver values, which demonstrates the same principle.

Kidney damage. Not demonstrated in healthy adults. The International Society of Sports Nutrition rates the safety profile in healthy people as favorable in its 2017 position stand. With pre-existing kidney disease, medical review beforehand is needed.

Quality and Purity: What the Literature Mentions

Several criteria are named in the discussion of creatine product quality:

• Purity. High purity as stated by the manufacturer.
• Additives. Pure creatine monohydrate without flavors, sweeteners or fillers.
• Lab testing. Batch analyses for contamination (heavy metals, dihydrotriazine).
• Storage. Dry and light-protected. Creatine in powder form is stable but breaks down in humid solution.

For a systematic approach to supplement quality, read the supplement beginners guide.

Which Groups Have Been Studied

In studies, well-trained, young, meat-eating men with adequate sleep showed smaller effects. Their stores are often close to saturation already.

Putting It in Context for Self-Tracking

Self-tracking can make trends visible, but it does not replace medical assessment.

1. Record baseline values. Weight, strength values (e.g. bench press 5RM), creatinine and cystatin C. You can document these in Lab2go.
2. Compare the course. Lay weight, strength values and lab results side by side over several weeks and look at the trend.
3. Discuss anything unusual. Changed lab values, symptoms or questions about kidney function belong in a medical consultation.

For regularly reviewing your own routines, read the cyclic routine playbook. The matching Lab2go plans and pricing are here.

This article is for information only and does not replace medical advice. With kidney disease, medication use or unclear lab values, speak with your doctor beforehand. Use, dose and therapy should be cleared with a doctor. Self-tracking complements medicine. It does not replace it.