A recent safety review of the field analysed 685 clinical trials of a single supplement. That number alone tells you something about creatine’s standing in sports nutrition. Three decades of research, hundreds of controlled studies, and the pattern that keeps surfacing has very little to do with the people the supplement was originally marketed to.
The trail leads back to Roger Harris, a biochemist working at the University of Nottingham Medical School in 1992. Harris fed creatine monohydrate to a small group of volunteers and measured what happened inside their thigh muscles. The compound flooded in. Muscle creatine concentrations climbed substantially in a week, and the people who started with the lowest baseline levels climbed the steepest. That early paper opened the research lane that has since produced the 685-trial body of evidence now under review.
And the pattern Harris glimpsed in lower-baseline subjects has refused to go away.
Three decades later, the people who may have the most room to respond to creatine are still often the ones whose diets contain no red meat, no chicken, no fish. The supplement built for bodybuilders turns out to do some of its most interesting work in the bodies of people who would never set foot in a steakhouse.
What creatine actually is, and where it comes from
Creatine is a small nitrogen-containing molecule the human body synthesises in the liver, kidneys and pancreas from three amino acids: glycine, arginine and methionine. Roughly half of the body’s daily requirement comes from this internal production. The rest is usually supplied by food, and food here mainly means animal tissue. Beef, poultry and fish all contain creatine. Plants contain essentially none.
The molecule’s job inside muscle and brain cells is brutally simple. It helps form phosphocreatine, which donates phosphate to spent ADP to regenerate ATP, letting cells keep firing during the first seconds of explosive demand. A sprinter leaving the blocks, a chess player grinding through hour five of a classical game, a neuron under metabolic stress. All of them are drawing on the same energy-buffering system.
Which means that the baseline you walk around with matters. And the baseline depends partly on what you eat.
The vegetarian gap
Long-term vegetarians and vegans tend to have lower creatine intake than omnivores because their diets contain little to no direct dietary creatine. The body compensates by making its own, but supplementation studies have repeatedly suggested that people starting from lower baseline stores can have more room to move when creatine is added.
This is why supplementation can look different in people who do not eat meat. When a vegetarian or vegan takes three to five grams of creatine monohydrate per day, the rise in available creatine may be more noticeable than the same dose given to a steady meat-eater already consuming creatine through food. Several controlled trials have examined memory and reasoning outcomes in vegetarians and vegans, and the cognitive findings in those groups remain one of the more intriguing signals in the literature. The broader health evidence now extends well past athletic performance into cellular energy, cognitive function and healthy ageing.
Why the meat-eater plateau matters
Roger Harris’s 1992 paper also helped document a ceiling. Muscle can only hold so much creatine. Habitual omnivores tend to live closer to that ceiling already because meat and fish contribute dietary creatine before any powder is added. Supplementing them can still produce real gains, especially in repeated high-intensity effort, but the subjective difference may be smaller than it is for someone starting from a lower baseline.
For a vegan or vegetarian athlete, by contrast, the same dose may feel more consequential. The biochemistry makes the anecdote plausible: if the gap between baseline and ceiling is wider, the supplement has more space to fill. That does not mean every plant-based person will respond dramatically. It means the diet pattern changes the starting line.
The women problem the field is still catching up to
For much of creatine’s research history, the test subjects looked like the easiest people for sports nutrition labs to recruit: young, male and athletic. Women were under-sampled to a degree that has only recently become uncomfortable to read about. Analysis of the field’s demographic history points out that early sports nutrition research followed athletic populations that historically skewed heavily male.
The consequence is that some of the most interesting physiological questions in women are still being mapped. Women may consume less dietary creatine on average, may begin from different baseline stores, and experience hormonal changes across the menstrual cycle, perimenopause and menopause that make creatine kinetics more complicated than the early male-heavy literature could capture. Early findings suggest creatine may have relevance for strength, lean mass and some brain-energy outcomes in women, but the field is still catching up to the question it should have asked earlier.
The hair-loss rumour, and what the data actually shows
No conversation about creatine survives long without someone raising the question of whether it causes baldness. The rumour traces to a single 2009 study in college-aged rugby players that measured a rise in dihydrotestosterone, the androgen most associated with male-pattern hair loss, after three weeks of supplementation. The study did not show hair loss in those players, and the measured hormone levels remained within the normal clinical range. A detailed review of the hair-loss claim notes that later clinical trials have not replicated the South African study’s DHT finding.
The rumour persists because creatine can increase water retention inside muscle cells, and early changes during loading can make people scrutinise their bodies more closely than usual. Confirmation bias does the rest.
The newer findings nobody saw coming
One of the more surprising recent papers came out of a cancer immunology lab. Researchers reported in June 2026 that creatine uptake appeared to support dendritic-cell activation and antitumour immunity in cell and mouse models. The finding is scientifically interesting because it points to the same energy-buffering chemistry that made creatine famous in muscle, but the authors and coverage were clear that it is not a human treatment recommendation.
That distinction matters. Creatine’s story keeps expanding beyond the gym, but not every new signal is ready to become advice. Some findings are mature enough for sports nutrition. Others are still early biology.
Why the supplement keeps outlasting its trends
Creatine first arrived in mainstream sports nutrition in the early 1990s, the same decade Olympic athletes and professional teams helped pull it into public view. The supplement industry that grew around it has cycled through dozens of competing molecules. Nitric oxide boosters, branched-chain amino acids, beta-alanine blends, exotic peptides. Creatine has outlasted all of them.
The reason is the data. The broader literature now describes creatine monohydrate as one of the few supplements whose core claims have repeatedly cleared the bar of controlled trials. Three to five grams a day, taken consistently, can produce measurable changes in strength, lean mass and repeated high-intensity performance. Its possible roles in cognition, ageing and recovery are still being actively studied. The required dose is small. The cost is trivial. The safety profile, across more than three decades of monitoring, has largely held up in healthy adults using standard doses.
The strangest part of the pattern
What keeps surfacing in the trial data is not simply that creatine works. That part has been argued less and less since the late 1990s. What keeps surfacing is who may have the most room to benefit.
So consider the irony plainly. A supplement engineered for meat-eating men chasing heavier lifts produces some of its clearest cognitive signals in vegetarians. Some of its most underexplored questions sit in women, older adults and people whose food patterns leave them starting from a lower baseline. The newest immunology work has nothing to do with deadlifts at all.
Roger Harris was trying to answer a narrow question about phosphocreatine kinetics in human muscle. What he helped clarify was something simpler and more durable: the body has a creatine baseline, diet helps shape it, and the people farthest from the ceiling have the most room to move. The plastic tubs sold at gym-supply stores are still labelled for the wrong audience.
