Creatine Beyond the Gym: Cognition, Aging, and Mood

Creatine is the most-studied supplement in the world. It's also been almost exclusively framed as a gym supplement for the last 30 years, which has caused most people who could benefit to dismiss it.

The research case for creatine in three other domains (cognition, healthy aging, and mood) has strengthened considerably in the last decade. The dose is small, the cost is trivial, the safety profile is excellent. For most adults, the case for taking creatine has very little to do with the gym.

What creatine actually does

Creatine is a molecule the body uses to regenerate ATP, the cellular energy currency. About 95% of the body's creatine is stored in skeletal muscle; the rest is in the brain, heart, and other tissues.

Supplementation increases the total pool. The benefit is largest in tissues that hit ATP limits during demanding work: muscles during high-intensity exercise (the gym story), the brain during cognitive load, sleep deprivation, or aging (the newer story).

The mechanism is the same. Only the context differs.

The cognitive evidence

The strongest cognitive benefits show up under conditions of demand: sleep deprivation, hypoxia, mental fatigue, or in vegetarians whose baseline brain creatine is lower.

Notable findings from the research:

• A 2024 meta-analysis (Forbes et al.) of 23 trials found creatine supplementation improved short-term memory and reasoning performance, with effect sizes larger in older adults and vegetarians.
• Sleep-deprived adults given 5g of creatine show measurably faster reaction times and better working memory than placebo across multiple trials.
• Vegetarians, who get little to no dietary creatine (it's primarily found in meat and fish), often see the largest cognitive boost from supplementation.

The mechanism is plausible. The brain uses around 20% of the body's energy. Cognitive tasks that demand sustained attention and working memory hit ATP limits in specific brain regions. Increasing the creatine pool gives those regions more headroom.

The aging case

Sarcopenia (age-related muscle loss) and reduced bone density are two of the biggest drivers of late-life frailty. Creatine has good evidence for both, even in non-exercising older adults, but particularly when combined with resistance training.

Worth knowing:

• A 2022 meta-analysis of trials in adults over 65 found creatine plus resistance training produced significantly greater gains in lean mass than training alone.
• Creatine also has emerging evidence for bone health in postmenopausal women, with one large trial showing reduced bone loss at the femoral neck over 12 months.
• Resting brain creatine declines with age. Some preliminary work suggests supplementation may partly offset age-related cognitive decline, though this is still early.

The combined story for older adults (muscle, bone, brain) makes creatine one of the few supplements with multi-system support in this age group.

Mood and depression

This is the area where the evidence is most preliminary but most interesting.

Several small RCTs have shown creatine added to standard antidepressant therapy improves response rates and speeds recovery, particularly in women. A 2023 trial in adults with major depressive disorder found 5g/day of creatine alongside SSRIs produced significantly greater symptom improvement than SSRIs alone at 8 weeks.

The proposed mechanism: depression is associated with altered brain energy metabolism, and creatine supplementation supports ATP regeneration in the brain regions most affected.

This is not yet a standard of care. But for adults already taking creatine for other reasons, the mood evidence is a useful bonus rather than a separate decision.

Dose, form, and timing

Dose: 3 to 5g per day. Higher doses don't produce better outcomes once muscle stores are saturated. The classic "loading phase" (20g/day for a week) reaches saturation faster but isn't necessary and increases GI side effects.

Form: creatine monohydrate. It's the cheapest, most-studied, and most effective. Other forms (creatine HCl, ethyl ester, buffered creatine) are marketed as superior but the research doesn't support the price difference.

Timing: doesn't really matter. Take it whenever is most convenient. The body's pool turns over slowly, so consistency over weeks matters far more than time of day.

With or without food: either works. Some evidence suggests slightly better uptake when taken with a carbohydrate-containing meal, but the difference is small.

Hydration: creatine pulls water into muscle cells. Adequate water intake helps but you don't need to drink unusual amounts.

Side effects and safety

Creatine has been studied at doses up to 30g/day for years with no serious adverse effects in healthy adults. The most common minor effects:

• Water retention: 1 to 2 kg of water weight in the first 2 weeks, stabilising after. Not fat gain; it's intracellular water in muscle.
• GI upset: mostly during loading phases or at doses above 10g/day. Resolves on lower doses.
• Hair loss claims: persistent online concern based on a single small study (Van der Merwe 2009) that showed increased DHT in rugby players. No follow-up study has replicated it. The hair loss connection is poorly supported.

Worth checking with your doctor: if you have kidney disease, creatine is metabolised to creatinine, which is the marker doctors use to assess kidney function. Supplementation will raise your creatinine number without necessarily indicating kidney damage. Mention you're taking it before any kidney function blood test.

Who's most likely to benefit

• Vegetarians and vegans: lowest baseline brain and muscle creatine; largest absolute effect from supplementation.
• Adults over 50: muscle preservation, bone density, possible cognitive support.
• People with high cognitive demand and poor sleep: parents of young children, shift workers, people in demanding jobs.
• Anyone doing resistance training: the original case, still valid.

Who probably doesn't need it

• Heavy meat-eaters with no specific cognitive or training reason; dietary creatine is likely already meeting needs.
• People with kidney disease (talk to your doctor first; not unsafe but the creatinine interpretation gets complicated).
• People who won't actually take it consistently. Creatine works through saturation; intermittent use produces intermittent benefits.

How Stack Almanac handles creatine

Creatine is in the Stack Almanac catalogue as a foundational supplement, not a gym-specific one. The Almanac Advisor will note creatine's relevance to cognition and aging when it's appropriate for your context, rather than only flagging it for users tracking strength training.

If you log creatine alongside an antidepressant, the Advisor will surface the relevant emerging research without overstating it. If your kidney panel is logged, it will note that creatine raises baseline creatinine numbers so the result is interpreted correctly. The point is to surface what's relevant rather than what's loudest.

Creatine earns a place in three of Stack Almanac's protocols for exactly these reasons: athletes for performance, over 40s for muscle and cognitive preservation, and energy for ATP-driven fatigue support.