Most of my work involves debunking numbers that sound impressive but don't hold up. Supplements are a perfect example: someone gets excited about a compound, a study gets misquoted, and soon there's a $40 tub of it in every kitchen. So it was a surprise to find that creatine's hype is actually attached to something real—mostly. Let me show you where the seams are.
What Creatine Was Actually Invented To Do
Start with the original purpose: boosting strength in people who are already training. A meta-analysis in Frontiers in Nutrition pooled eleven randomized trials of over-60s who lifted weights, with half also taking creatine. The creatine group got significantly stronger on average than those doing identical training without it. The effect size of 0.31 means the average creatine user finished stronger than roughly 62% of the placebo group—so 38% of those who took nothing still beat the average person on creatine. That's a real edge, and I'd take it, but it's not what Instagram is selling you today.
The Water Weight Illusion
Now, the study that should make you distrust your bathroom scale. A team at the University of New South Wales published a trial in Nutrients last year. They supervised 63 adults—half on five grams of creatine daily, half on placebo—through 12 weeks of supervised lifting. But they also included a seven-day "wash-in" before anyone touched a weight, and they used DEXA scans at every stage. After that first week of creatine and zero exercise, the supplement group had gained half a kilo of what the scanner read as "lean body mass." But muscle doesn't materialize in seven days—that was water pulled into muscle cells, which DEXA counts as lean tissue. Over the 12 weeks of real training, both groups gained about two kilos, and the gap between them disappeared. Same training, same result, whether or not you paid for the powder.
That study explains why so many people feel enormous after a few days on creatine. They measured a real thing at the wrong moment and drew the wrong conclusion. The supplement industry has been quietly selling that first week for 30 years. The scale and the customer are both fooled, even though no one is technically lying.
The Brain Hype
Around 2024, creatine started being marketed as a cognition and memory enhancer. One industry analysis counted 469 podcast episodes on creatine in 2025 alone—more than the entire preceding decade combined—with brain-focused framing in titles nearly doubling in two years, and one in six telling listeners they need to take it. The evidence underneath that noise is thin. A 2024 review pooled sixteen randomized trials on creatine and cognition, but only 492 participants total, across ages 20 to 76, with different doses and durations. They found small improvements in memory and attention, but no statistically significant effect on overall cognitive or executive function.
There's also a statistical problem in this literature. An earlier meta-analysis in Nutrition Reviews reported a memory benefit, but a letter to the journal pointed out that multiple outcomes measured on the same participants were treated as independent observations—double-counting the benefits and artificially narrowing confidence intervals. That makes a wobbly result look settled. It's a boring technical error, but it's everywhere.
Break those memory results out by age, and the story falls apart. For adults 66 to 76, the effect size is genuinely large, but it's negligible for ages 11 to 31. So a fair reading is that creatine might help an older brain running short on metabolic headroom, but it does approximately nothing measurable for a well-rested 27-year-old—the guy who's actually buying all that creatine.
Safety: The Panic Is Overblown
In fairness, the safety panic has outrun the data. Creatine does not hurt healthy kidneys. The International Society of Sports Nutrition says so, as does a meta-analysis of renal function in athletes. A full season of monitoring in 71 female soccer players found nothing beyond clinically trivial wobbles in bloodwork. Creatine does raise serum creatinine (note the extra two letters), which is the metabolite your doctor uses as a proxy for kidney function. So your lab report might look frightening after creatine, even if nothing is wrong. If you have kidney disease, ask your doctor before taking it. If you don't, tell him you're taking it before he tests you and panics over your labs.
The Longest Trial Keeps Me Cautious
I want to finish with the study that keeps me cautious, even as I'm persuaded. The biggest and longest trial in the field put 237 postmenopausal women on about 10 grams a day for two years, alongside supervised resistance training and walking. The results are still being analyzed, but the sheer duration and the population—older adults—suggest that any cognitive or strength benefits are most likely to show up in those with lower baseline capacity, not in healthy young gym-goers. That's the fine print the marketing rarely mentions.
So, creatine works—but it works for strength in people who are already training, and possibly for memory in older adults. The rest is water weight and hype. Read the labels, ignore the podcast ads, and if you're under 30, don't expect a brain boost.
