If it feels like everyone is suddenly talking about creatine, from your trainer to your favorite podcast to your aunt who just discovered strength training, you're not imagining it. For years creatine lived in the "gym junkie" corner of the supplement world. Now longevity researchers and healthspan enthusiasts are interested too, not just for muscle but for brain energy and healthy aging. So what changed, and how much of the hype is real?
This is Part 1 of our creatine series. Here we cover what creatine is, what the best current research says about muscle, brain and aging, and why experts see it as more than a bodybuilding supplement. In Part 2 we look at Muscle Memory and why we chose one specific form of creatine, and in Part 3 we get practical about how to take it.
Creatine 101: your cells' fast-acting battery pack
Creatine is a compound your body makes, mainly in the liver and kidneys, from the amino acids arginine and glycine. You also get some from food, mostly red meat and seafood. About 95% of your creatine is stored in skeletal muscle, with small amounts in the brain and other tissues.
Your cells run on ATP, their main energy currency. During high-demand moments, like lifting a weight, sprinting or thinking hard on little sleep, ATP gets used up quickly. Creatine sits in your cells as phosphocreatine, ready to donate a phosphate and regenerate ATP fast. Think of it as a small, fast-acting battery pack.
Your body needs to replace roughly 1 to 3 g of creatine a day, and about half of that typically comes from diet. On a normal diet, muscle creatine stores are only about 60% to 80% full, and vegetarians tend to have lower stores, which is why 3 to 5 g a day of creatine monohydrate is so common in research.
The muscle story: creatine and "muscle span" as you age
Creatine is one of the most studied supplements for strength and performance, and the effects are clearest in activities built on short bursts of effort. Systematic reviews consistently show that creatine adds to the effects of resistance training:
- In older adults, a meta-analysis of trials found creatine plus strength training led to about 1.4 kg (3 lb) more lean mass than training with a placebo, along with greater chest-press and leg-press strength.
- In adults under 50, creatine with resistance training increased upper- and lower-body strength more than training alone.
Zoom out and it becomes a healthy-aging story. We naturally lose muscle and strength with age, and that loss, called sarcopenia, is linked to a higher risk of falls and fractures. Resistance training is the foundation for keeping "muscle span", and creatine seems to help you get a little more out of it.
An important nuance: the benefits show up when creatine is paired with training, not taken on its own. And when researchers measure muscle growth directly with imaging, the extra gain is real but very small, which is one reason some headlines call creatine "overrated" despite a positive overall picture.
The brain story: promising, but still emerging
This is where creatine's new reputation comes from, and where nuance matters most.
- Memory: a 2023 meta-analysis found small overall improvements in memory with creatine, with bigger effects in older adults (66 to 76 years) and little effect in young adults.
- Attention and processing speed: a 2024 meta-analysis of 16 trials found small improvements in memory, attention and processing speed, but no improvement in overall cognitive function or executive function.
- Under stress: creatine seems to matter most when the brain is under metabolic strain. In a 2024 randomized trial, a single large dose (0.35 g/kg, about 20 to 30 g depending on body weight) helped sleep-deprived participants maintain cognitive performance and changed markers of brain energy metabolism. That was a lab protocol, not a dosing recommendation.
A 2023 review in Sports Medicine concluded that creatine can raise brain creatine levels and may offer cognitive benefits, especially under stress and in older adults, but that results are inconsistent and more high-quality trials are needed.
In plain terms: it's fair to say creatine may support brain energy and some aspects of cognitive performance, especially in older or stressed brains. It is not accurate to say creatine makes you smarter or treats or prevents cognitive disease.
Creatine, women and healthy aging
One big reason creatine is having a moment: women and older adults are finally being studied directly. Recent reviews of creatine in women's health point to benefits for muscle strength, exercise performance and body composition when combined with resistance training, and possible benefits for mood and cognition, while noting that data on perimenopausal women is still limited.
- Muscle and strength: creatine plus strength training supports lean mass and strength, which matter more as estrogen declines.
- Bone: a 2025 meta-analysis in older adults found creatine with exercise improved strength and body fat but not whole-body bone density, so bone effects need more study.
- Mood: a small number of trials have tested creatine alongside standard treatment for depression. It's early-stage research and not a basis for any treatment claim.
For women who eat mostly plant-based, are 40-plus and noticing changes in muscle or recovery, or are lifting to protect bone and muscle, creatine is increasingly discussed as a simple, well-studied supplement to pair with training. We go deeper in estrogen and creatine.
Is creatine safe?
For most healthy adults, the safety data is strong for a supplement:
- A 2025 analysis of 685 creatine studies and 652 placebo studies found side effects were reported about equally often with creatine and placebo.
- A 2025 meta-analysis on kidney function found creatine can slightly raise serum creatinine, a lab marker, but did not change kidney filtration (GFR) in the included studies.
- The International Society of Sports Nutrition concluded that short- and long-term use, up to 30 g a day for five years, has been well tolerated in healthy people.
Typical research doses are 3 to 5 g a day. A "loading phase" of about 20 g a day for 5 to 7 days fills muscle stores faster but isn't required, and it's more likely to cause temporary water retention or stomach upset. People with kidney disease or other serious medical conditions, and anyone pregnant or breastfeeding, should talk to a health professional first. The very high doses used in some cognitive trials are not consumer recommendations.
What this means for you
- Creatine isn't a fad. It's a core energy shuttle for muscle and brain that has been studied for decades.
- For muscle and physical function, especially with strength training and aging, the benefits are well supported.
- For the brain, the evidence is promising but early: worth studying, not strong enough for big promises.
- At standard doses in healthy adults, creatine is generally well tolerated.
In Part 2, we explain why researchers default to creatine monohydrate, how German-made creatine set the quality bar, and how we built Muscle Memory around it. In Part 3, we cover how to take creatine whether you lift four times a week or mostly walk and do yoga, what to pair it with, and when to talk to your doctor. If you're plant-based, you may also like plant-based protein for body and brain.
This article is for education only and isn't medical advice. Talk to your healthcare provider before starting any new supplement, especially if you have kidney, liver or other medical conditions, are pregnant or breastfeeding, or take prescription medication. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
