Creatine and the brain: memory, mental fatigue, depression

Creatine is not just about muscle: it also increases in the brain, but by a small amount, around 5 to 15% in a few weeks. In the young and well-nourished adult, the effect on memory and reasoning is small, sometimes nil. It is more visible after the age of 60, and when the brain is deprived of sleep or oxygen. Here is what twenty-two studies measure.

Does it actually reach the brain?

Yes, and we know how to measure it, using magnetic resonance spectroscopy. In six young volunteers, four weeks of creatine at 20 g per day (4 × 5 g) increased brain creatine by an average of 8.7%, from 4.7% in the gray matter up to 14.6% in the thalamus. Three months after stopping, everything had returned to baseline.

In fifteen healthy men, one week at 0.3 g per kilo per day, followed by one week at 0.03 g, gave the same order of magnitude: 8 to 9% more creatine compared to placebo, and slightly more phosphocreatine (+3.4%). Another team measured +9.2% after seven days.

But it does not work for everyone. In 67 children aged 10 to 12, seven days of creatine changed neither their brain creatine nor their scores on learning and reasoning tests. The authors believe that at this age, the brain relies mainly on the creatine it produces itself. A 2024 systematic review summarizes: brain creatine increases, but "to a limited extent".

Memory and reasoning: a small effect, especially in older adults

The first systematic review, in 2018 (six trials, 281 people), saw a possible gain on short-term memory and reasoning, results that were contradictory elsewhere, and nothing in young people. The 2023 meta-analysis on memory (eight trials) quantifies the effect: a standardized difference of 0.29, which is small. It is clear in 66- to 76-year-olds (0.88) and absent in 11- to 31-year-olds. Neither the dose (2.2 to 20 g per day) nor the duration (5 days to 24 weeks) changed the result.

The 2024 one, covering sixteen trials and 492 adults, finds an effect on memory (0.31), attention (0.31) and especially information processing speed (0.51), but no effect on global cognition or executive functions.

Trials in young adults point in the other direction. In 22 young adults, six weeks of creatine changed nothing in a full battery of tests: reaction speed, logical reasoning, calculation, memory. In 40 active youths, one week at 20 g per day increased power on a 30-second cycling sprint (from 526 to 570 watts on average), with no effect on cognitive tests.

The largest trial to date, in 2023, followed 123 people: 5 g per day for six weeks, versus placebo, each receiving both. Result: a small probable effect according to Bayesian analysis, at the limit of significance on a working memory test (p = 0.064), nothing on the reasoning test, and nothing on the eight other tests. And side effects were reported four times more often with creatine than with placebo.

Do vegetarians benefit more?

The 2018 review suggested this for memory. Trials do not agree. In 45 young vegetarians, 5 g per day for six weeks significantly improved working memory and an intelligence test. In 128 young women, five days at 20 g per day improved memory in vegetarians only. But in the large 2023 trial, which included half vegetarians, the latter did not benefit more than omnivores.

After 60 years old

In 32 elderly people, one week at 20 g per day improved almost all memory tests, with the exception of digit span backward. In elderly women followed for 24 weeks, however, creatine changed neither memory nor attention, with or without weight training. In this trial, weight training alone reduced depression scores, without creatine adding anything to it.

A 2026 review dedicated to those over 55 counts five positive studies out of six (1,542 participants). But only two are double-blind trials; the other four estimate dietary creatine by questionnaire, and half of the studies are judged to be of poor quality.

When the brain is at its limit

This is where the results are most consistent. After five days at 8 g per day, volunteers performing simple calculations felt less mental fatigue, and their brain seemed to consume more oxygen. During sleep deprivation with moderate exercise, seven days at 20 g per day improved a complex working memory task, but only after 36 hours without sleep, and nothing else.

In fifteen young adults who breathed air with 10% oxygen for 90 minutes, attention decreased under placebo and was maintained under creatine, after one week of supplementation.

And depression?

In 52 women with depression, 5 g of creatine per day added to an antidepressant (escitalopram) reduced symptoms faster than placebo, starting in the second week, with an advantage maintained at eight weeks. In 100 depressed individuals following cognitive behavioral therapy, added creatine lowered the depression score by 5 points more than placebo in eight weeks, with a similar number of side effects.

The 2025 meta-analysis, on eleven trials and 1,093 participants, tempers this: the average effect equals 2.2 points on the Hamilton scale, below the minimum difference considered important for a patient (3 points). The authors note a significant bias in favor of creatine and judge the evidence to be of very low quality. The true effect could be zero.

In short

The doses studied for muscle are on the creatine page, and its side effects in our article on the dangers of creatine. If it is your concentration you are looking to support, the supplements studied for the brain are gathered in the cognition theme.

Every figure in this article comes from a study you can open: the underlined mentions lead to the summary of the work it is taken from, written solely from the abstract. Informative content, which does not replace the advice of a healthcare professional.