Creatine Beyond Muscle: Brain, Mood, Aging and Safety

Why creatine reaches past muscle

Creatine helps cells recycle ATP, their short-term energy currency, quickly. Muscle holds most of the body's creatine, which is why the sport evidence is so solid: with resistance training, creatine increases strength, power and lean mass, and the site rates that use strong. The brain also runs on the same system, and that is where most of the newer research points. The question this page answers is simple: which of those newer uses hold up, and which are still hope.

The short version, before the detail:

Cognition, sleep loss and mental fatigue

Memory and thinking

The best summary is a 2024 meta-analysis of 16 randomized trials with 492 adults aged 20.8 to 76.4, all using creatine monohydrate¹. Creatine improved memory (standardized mean difference 0.31), attention time and processing speed, but did not improve overall cognitive function or executive function. The authors graded the memory finding as moderate certainty and everything else as low certainty. Benefits looked larger in people with diseases, in adults aged 18 to 60 and in women.

An earlier meta-analysis limited to healthy people found a similar overall memory effect (SMD 0.29) across 8 trials, but with a twist: the gain was clear in adults aged 66 to 76 (SMD 0.88) and essentially absent in people aged 11 to 31 (SMD 0.03)². Doses ranged from about 2.2 to 20 g per day and did not change the result.

The largest single trial so far tempers expectations. In a preregistered crossover study of 123 people taking 5 g a day for 6 weeks, creatine only bordered on significance for a working-memory test and did not improve a reasoning test or eight exploratory tasks³. The authors concluded the effect is, at most, small. Side effects were reported more often on creatine than on placebo.

Verdict: moderate for a small memory benefit, most likely in older adults. Limited for the idea that creatine makes healthy young people sharper. If you want a brain supplement, this is not a dramatic one.

Sleep deprivation and mental fatigue

Reviews agree that creatine is most likely to matter when the brain is under stress, such as sleep loss, low oxygen or demanding tasks⁴. The direct evidence is thin. In one study, a single large dose of creatine monohydrate (0.35 g per kg of body weight) during 21 hours without sleep changed brain energy markers measured by scanning and improved cognitive performance and processing speed compared with placebo⁵. A follow-up in 29 healthy people using a lower single dose (0.2 g/kg) found a smaller protective effect, up to 12%, on logic, number and vigilance tasks⁶.

For mental fatigue, a crossover trial in 14 people loading 20 g a day for 7 days found better accuracy during a 90-minute mentally tiring task, but creatine did not prevent the fatigue-related drop in short reaction-time or attention tests afterward⁷.

Verdict: limited. These are small, short studies, and the single doses used are far above what anyone takes daily. They are interesting signals, not a reason to replace sleep with a scoop of powder.

Depression as an add-on

This is where the marketing runs furthest ahead of the data. A 2025 meta-analysis of 11 trials with 1,093 participants found a small average improvement in depressive symptoms (SMD -0.34), equal to about 2.2 points on the Hamilton scale, which is below the 3-point change that patients notice as meaningful⁸. Certainty was rated very low, heterogeneity was high, and bias adjustments suggested the true effect may be trivial or null. Remission looked better in three trials, but response did not in two.

A 2026 systematic review limited to people with a diagnosed mental disorder found only five trials, using 2 to 10 g a day for 4 to 8 weeks as an add-on⁹. Creatine beat placebo when combined with escitalopram and when combined with cognitive behavioral therapy, but not in female adolescents on medication or in bipolar depression. Two of 17 participants on creatine experienced hypomania or mania.

Verdict: limited. Depression needs a doctor, not a supplement plan. If you are being treated and want to try creatine alongside, tell your prescriber first, and do not try it on your own if you have bipolar disorder.

Older adults, women and vegetarians

Older adults

A 2025 meta-analysis of 20 studies with 1,093 older adults found that creatine plus exercise produced a small extra gain in one-repetition maximum strength (about 2.1 kg) and a small drop in body fat percentage compared with exercise alone¹⁰. It did not change total-body bone mineral density. The key word is plus: the benefit rides on training.

Bone is the clearest negative. In a 2-year trial, 200 postmenopausal women with osteopenia took 3 g a day or placebo, and creatine did not improve bone density, bone markers, falls, fractures, lean mass or muscle function¹¹. Verdict: moderate for strength when paired with resistance training, limited for bone.

Women

Women were underrepresented in early creatine research, and the sport benefits seem to apply to them too. A 2026 meta-analysis of 14 trials in 763 women across reproductive stages found that supplements combined with exercise did not add muscle mass or bone density, but did improve bench press and handgrip strength, especially in the creatine studies¹². Some cognitive results above looked stronger in women¹⁶, but no trial was designed to settle that. For pregnancy, safety data are lacking and caution is advised¹³. Verdict: the same grades as for anyone else; nothing female-specific has better than limited support.

Vegetarians and vegans

Creatine comes mostly from meat and fish, so vegetarians start with lower stores. A systematic review of nine studies found supplementation raised muscle creatine in vegetarians, often above omnivore levels, and improved lean mass, strength and, in some studies, memory, though the studies had moderate to high risk of bias and creatine did not raise brain phosphocreatine¹⁴. The large cognition trial found vegetarians did not benefit more than omnivores³. Verdict: moderate for muscle stores and training, limited for a special brain benefit.

Brain injury and other clinical areas

Concussion and traumatic brain injury get a lot of attention, but human data are scarce⁴. The most cited study is an open-label pilot in 39 children and adolescents with brain injury given 0.4 g/kg daily for 6 months, which reported better cognition, behavior, self-care and communication¹⁵. Without blinding or a placebo, it cannot show cause. In Alzheimer's disease, a single-arm pilot in 20 patients taking 20 g a day for 8 weeks raised brain creatine by 11% and found cognitive improvements, but there was no control group¹⁶.

A reminder of why pilots are not proof: in Parkinson's disease, a large trial randomized 1,741 patients to 10 g a day or placebo for at least 5 years and was stopped early for futility, with no difference in clinical decline¹⁷. Verdict: limited across clinical areas. Anyone with a neurological condition should discuss creatine with their doctor rather than self-treat.

Safety myths: kidneys, hair, water

Kidneys. A 2026 meta-analysis of 19 randomized trials and one crossover study found creatine raised serum creatinine by about 0.13 mg/dL, with no change in urea or estimated kidney filtration (eGFR)¹⁸. Creatinine is a breakdown product of creatine, so a rise on blood tests is expected and is not the same as kidney damage. Tell your doctor you take creatine before a kidney panel. The authors note that trials beyond 1 year are still needed. If you already have kidney disease, do not take creatine without medical supervision.

Hair loss. The worry comes from the idea that creatine raises DHT. In a 12-week randomized trial, 45 resistance-trained men took 5 g a day or placebo, and there were no differences in DHT, the DHT-to-testosterone ratio, hair density or hair thickness¹⁹. One trial is not the last word, but the claim has no direct evidence behind it.

Water weight. This one is partly true. Loading at 25 g a day for 7 days, then 5 g a day, increased body mass and total body water, but the split between water inside and outside cells did not change²⁰. Expect about 1 to 2 kg early on. That is not fat and not bloating under the skin. Claims that creatine causes dehydration or cramps are not supported by controlled studies, though high doses can upset the stomach¹³.

Dose and what to buy

For muscle and general use, the evidence-based dose is 3–5 g of creatine monohydrate every day, with or without a loading phase, and no need to cycle. For the brain, reviews suggest higher or longer dosing may be needed to raise brain creatine, and the best strategy is unknown⁴. The trials that showed cognitive effects used anything from about 2.2 to 20 g a day². A reasonable approach is to take 5 g daily for at least several weeks and not to chase the large single doses used in sleep-deprivation labs.

Buy plain creatine monohydrate. It is cheap and is the form used in essentially all of the research above¹. The alternatives do not improve on it:

• Creatine HCl dissolves better but has no performance advantage, contains less creatine per gram (about 78% versus 88%), and its tiny label doses have no loading data.
• Kre-Alkalyn is sold on a false premise about stomach breakdown, and at the 1.5 g label dose it failed to raise muscle creatine.
• Creatine ethyl ester breaks down into creatinine in the stomach, loaded muscle less than monohydrate and sharply raised serum creatinine. Do not buy it.
• Creatine gummies are monohydrate in a convenient form, but most hold 1–1.5 g each, so you need 3–5 a day, with added sugar.

Bottom line

Creatine monohydrate is a strong supplement for strength and lean mass when you train, including later in life. Outside muscle, the honest picture is narrower: a moderate case for a small memory benefit, mostly in older adults, and limited evidence for sleep loss, mental fatigue, depression, women-specific benefits, brain injury and dementia. It does not protect bone on its own and did not slow Parkinson's disease. It is safe for healthy adults at 3–5 g a day. Talk to a doctor first if you have kidney disease, are pregnant, have bipolar disorder or are being treated for depression or a neurological condition.