Creatine monohydrate is one of the most widely studied supplements in sport. It is a naturally occurring compound found in both muscle and brain tissue, where it is stored as phosphocreatine (PCr). Creatine plays a key role in rapid energy production by helping regenerate ATP, the body’s primary energy currency, particularly during short, high-intensity efforts such as strength training or repeated sprints.
Dietary creatine is obtained primarily from animal-based foods, including red meat and seafood. A typical omnivorous diet provides around 1–2 g per day, resulting in approximately 60–80% muscle creatine saturation. Supplementation increases these stores further, which may enhance the body’s ability to perform and recover from high-intensity activity. Creatine is rapidly absorbed, with peak blood levels occurring within approximately one hour, and excess is excreted as creatinine in the urine.
Supplementation protocols commonly include a loading phase of around 20 g per day (split into 4 doses) for 5–7 days, followed by a maintenance dose of 3–5 g per day, although requirements may vary depending on body size and training demands. A lower daily dose without loading can also gradually increase muscle creatine stores over time.
From a performance perspective, creatine has the strongest evidence for improving strength, power, and high-intensity exercise capacity. Research, including position stands from the International Society of Sports Nutrition, demonstrates consistent improvements in training capacity, allowing athletes to sustain higher workloads and recover more effectively between efforts. Over time, this can contribute to increases in lean muscle mass and strength, particularly when combined with resistance training. Some evidence suggests that untrained individuals may see larger initial gains, while trained individuals may utilise supplemented creatine more efficiently.
However, when focusing specifically on women, the evidence is less consistent. Women have historically been underrepresented in sports science research, with only around 30% of participants being female and a much smaller proportion studied in female-only trials. A recent systematic review by Tam R et al. (2025), which included 27 studies exclusively in active females, found mixed results. Improvements were seen in some studies of strength and anaerobic performance, but the majority showed no significant benefit compared to placebo. These inconsistencies are likely influenced by small sample sizes, varied training protocols, differences in dosing strategies, and limited consideration of female-specific physiological factors.
There is also emerging interest in the potential cognitive effects of creatine. Some studies suggest small improvements in memory and processing speed, particularly under conditions of fatigue or increased mental demand. These effects appear to be modest and are not always noticeable in everyday settings.
Creatine is generally considered safe and well tolerated in healthy individuals when used at recommended doses. Some people may experience mild gastrointestinal symptoms, particularly during the loading phase, and a small increase in body mass (typically 1–2 kg) can occur due to increased water retention within muscle.
Overall, creatine is a well-supported supplement from a physiological perspective, particularly for improving high-intensity performance. However, in women, current evidence shows variable outcomes, highlighting the need for more high-quality, female-specific research. As with any supplement, its use should be considered alongside individual goals, training demands, and overall health.
