⌑ I · The MechanismHow it actually works.
Creatine is synthesized endogenously in the liver, kidneys, and pancreas from the amino acids glycine, arginine, and methionine, and obtained exogenously from animal foods — primarily red meat and fish. Approximately 95% of total body creatine is stored in skeletal muscle, predominantly as phosphocreatine (PCr).[1]
Phosphocreatine functions as a rapid-release reservoir of phosphate groups, used to regenerate adenosine triphosphate (ATP) from adenosine diphosphate (ADP) during the first 10 seconds of high-intensity effort. The PCr system is the dominant energy pathway for maximal-effort work lasting between approximately one and ten seconds — a sprint, a heavy single, an explosive movement.[1][2]
Oral supplementation with creatine monohydrate increases intramuscular PCr stores by approximately 15-40% above baseline, depending on starting saturation. Higher baseline creatine concentrations (often present in habitual red meat consumers) correlate with smaller supplementation effects — the well-documented "non-responder" phenomenon, which affects approximately 20-30% of users.[1][3]
The effect is not stimulant. It is substrate. Creatine does not "activate" anything — it provides more raw material for the existing phosphate-recycling system, which means the limiting factor for short-duration maximal work shifts upward.
⌑ II · The EvidenceWhat the research actually shows.
The 2017 International Society of Sports Nutrition (ISSN) position stand, the most comprehensive review of the creatine literature, concluded that creatine monohydrate is "the most effective ergogenic nutritional supplement currently available to athletes with the intent of increasing high-intensity exercise capacity and lean body mass during training."[1]
Key consolidated findings across the literature:
- Strength gains. A meta-analysis of 22 studies by Branch (2003) reported a mean effect size of 0.24 favoring creatine for strength outcomes — a small-to-moderate effect translating to approximately 8% greater strength gains over placebo during resistance training.[4]
- Lean mass. The same meta-analysis found a mean effect size of 0.15 for lean body mass, with effects largest in untrained populations beginning resistance training.[4]
- Older adults. Devries and Phillips (2014) meta-analyzed creatine supplementation in older adults during resistance training and found significantly greater gains in lean tissue mass (+1.37 kg) and upper body strength compared to resistance training alone.[5]
- Cognitive function. A 2018 systematic review by Avgerinos et al. found creatine supplementation improved short-term memory and reasoning in healthy adults, particularly under conditions of sleep deprivation or mental fatigue.[6]
- Brain creatine. A 2022 review in Nutrients documented increased brain creatine concentrations with supplementation, with implications for traumatic brain injury recovery, depression, and neurodegenerative disease.[7]
⌑ III · The ProtocolHow to actually use it.
When will your muscles be saturated?
Enter your bodyweight and daily protocol. The chart shows your projected phosphocreatine saturation curve. The numbers tell you exactly when you hit functional saturation.
Daily dose
3-5 grams of creatine monohydrate, taken at any time of day, every day. Saturation of muscle PCr stores is achieved within approximately 28 days at this dose.[1]
Loading protocol (optional)
20 grams per day (split into 4 × 5 g doses) for 5-7 days, followed by 3-5 g daily maintenance. Achieves saturation in approximately 5-7 days rather than 28. Identical end-state outcomes.[1] Loading is a time preference, not a performance preference.
With what
Any liquid. Carbohydrate or carb + protein co-ingestion modestly increases retention via insulin response, but the difference at saturation is negligible.[8]
Timing relative to training
The 2013 study by Antonio and Ciccone comparing pre- vs post-workout creatine over 4 weeks found no statistically significant difference in body composition or strength outcomes between groups, with a slight non-significant trend favoring post-workout. Take it when it is most convenient — adherence beats timing.[9]
⌑ IV · Form and QualityWhy monohydrate, and only monohydrate.
Creatine is sold in many forms: monohydrate, ethyl ester, hydrochloride (HCl), buffered (Kre-Alkalyn), liquid, micronized. None of the alternative forms has demonstrated superiority to monohydrate in head-to-head trials. The ISSN position stand explicitly states that creatine monohydrate remains the most clinically effective form.[1][3]
Buy the form with the most data and the lowest cost per gram. That is monohydrate. Look for the Creapure designation (manufactured by Alzchem in Germany) for the most consistent purity verification, though properly manufactured generic monohydrate from any reputable supplier is also adequate.
The proprietary creatine market exists because monohydrate is off-patent and cheap. Premium-priced "advanced" forms have marketing budgets, not better outcomes. The science is unambiguous on this point.
⌑ V · Contraindications & ConsiderationsWhat to actually watch for.
Creatine has one of the strongest safety profiles in the supplement literature. Long-term studies up to 5 years have found no adverse effects on renal function, cardiovascular markers, or liver enzymes in healthy individuals at standard doses.[1][10]
Considerations that do apply:
- Pre-existing renal impairment. Individuals with diagnosed kidney disease should consult a physician before supplementation. The kidney metabolizes creatine, and elevated baseline creatinine values (used to assess kidney function) will rise predictably during supplementation — this is a marker artifact, not damage, but can complicate clinical interpretation.[1]
- Water retention. Initial supplementation typically causes a 1-2 kg increase in body water as muscle cells hold more intracellular fluid. This is the mechanism of the early "weight gain" effect and is not fat or fluid retention in the cosmetic sense.[1]
- Gastrointestinal discomfort. Rare at standard doses. More common with loading protocols at 20 g/day. Splitting doses and taking with food usually resolves it.[1]
The cramping and dehydration concerns historically associated with creatine are not supported by the literature. Greenwood et al. (2003) found that collegiate football players using creatine had significantly lower rates of cramping, heat illness, and muscle injuries than non-users over a season of training and competition.[10] The narrative persisted in coaching culture long after the data refuted it.
⌑ VI · Stacking and Co-SupplementationWhat pairs, what doesn't.
Creatine is foundational, not stacked. It works through its own pathway and does not require co-supplementation to function. Reasonable pairings include:
- Beta-alanine. Different mechanism (muscle carnosine buffering), different time domain (60-240 seconds of effort). Effects are independent and additive.[1]
- Caffeine. Older studies suggested caffeine might blunt creatine's effects; recent literature does not support that conclusion when both are dosed properly. See the caffeine protocol →
- Carbohydrate co-ingestion. Marginal effect on uptake, not on end-state outcomes.
Pairings that do not add value: creatine + "test boosters," creatine + "fat burners," creatine + proprietary blends. These exist because the supplement industry profits from complexity, not because the combinations are warranted by evidence.