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Amino Acids & Proteins

Creatine

Also known as: Creatine monohydrate, Methylguanidinoacetic acid

A compound made from amino acids that fuels short bursts of muscle power and is the most studied sports supplement in the world.

  • By IngredientWiki Editorial Team
  • Fact-checked by IngredientWiki Editorial Team
  • Updated 2026-09-25
  • 2 min read

In short

Creatine is a compound your body makes from three amino acids — arginine, glycine, and methionine — and stores mostly in muscle as phosphocreatine. During short, intense efforts like lifting or sprinting, phosphocreatine rapidly regenerates ATP, the cell's energy currency. Creatine monohydrate is the most researched sports supplement available, with decades of evidence showing it increases strength, power, and lean mass when combined with resistance training.

  • Stored in muscle as phosphocreatine, which rapidly regenerates ATP
  • Also found in red meat and fish; the body makes about 1 g per day
  • Standard dose: 3–5 g of creatine monohydrate daily
  • Weight gain of 1–3 lb is common and is mostly water in muscle

What is Creatine?

Creatine is one of the most heavily researched dietary supplements in existence, with thousands of studies spanning more than 30 years. Roughly 95% of the body's creatine is stored in skeletal muscle, where it acts as an energy buffer: by donating a phosphate group to ADP, phosphocreatine regenerates ATP faster than other pathways can, powering maximal efforts lasting up to about 10–15 seconds. Vegetarians and vegans tend to have lower muscle creatine stores and often see the largest responses to supplementation.

Where it comes from

Natural sources

  • Made in the liver, kidneys, and pancreas from arginine, glycine, and methionine
  • Red meat and poultry (about 1–2 g per pound of raw meat)
  • Fish such as herring and salmon

How it's made

Supplemental creatine monohydrate is produced synthetically from sarcosine and cyanamide.

What it does in products

  • Rapid ATP regeneration during high-intensity exercise
  • Increased training volume and recovery between sets
  • Cell volumization (water retention in muscle)
  • Emerging role in brain energy metabolism

Benefits

Strength and power gains

strong evidence

Meta-analyses of hundreds of trials consistently show creatine plus resistance training increases maximal strength and power output more than training alone, across ages and sexes.

Lean mass gains

strong evidence

By allowing more training volume, creatine supports greater muscle accretion. Typical gains over 4–12 weeks are 2–5 lb, with an initial 1–3 lb from intramuscular water.

High-intensity performance

strong evidence

Creatine improves repeated sprint and high-intensity interval performance, particularly in efforts lasting seconds rather than endurance events.

Brain health and cognition

emerging evidence

The brain also uses creatine. Early research suggests supplementation may blunt mental fatigue during sleep deprivation and is being studied in concussion recovery and aging populations.

Side effects & safety

Water retention and weight gain (common)Expected and usually desired; reflects creatine working in muscle cells.
Digestive upset with large single doses (uncommon)Splitting doses or skipping the loading phase prevents cramping and diarrhea.
Muscle cramps (rare)Older anecdotal reports; controlled trials do not show increased cramping with adequate hydration.

Safety considerations

  • Creatine has not been studied in pregnancy; standard guidance is to avoid use during pregnancy and breastfeeding out of caution.
  • Creatine increases muscle water content; staying hydrated is important, especially in heat.
  • Kidney function tests may show elevated creatinine, which is a normal artifact of supplementation, not kidney damage.
  • Not for: Pre-existing kidney disease (use only under medical supervision)

How it's used

In supplements

Standard daily dose: 3–5 g of creatine monohydrate. A loading phase of 20 g daily (split into 4 doses) for 5–7 days saturates muscle stores faster but is optional — the same levels are reached in about 3–4 weeks with the daily dose. Timing around workouts is less important than consistency.

Regulatory status

  • Dietary supplement regulated by the FDA under DSHEA. Creatine monohydrate has a long safety record and is permitted in international sport, including by the World Anti-Doping Agency.
  • GRAS (generally recognized as safe) for food use.

Popular products containing Creatine

  • Micronized Creatine Monohydrate — Flavorless powder that dissolves more easilyOptimum Nutrition · supplement
  • Creatine — NSF Certified for SportThorne · supplement
  • Creatine Monohydrate PowderBulkSupplements · supplement

Product names and brands are shown for reference and belong to their respective owners.

Creatine monohydrate vs other forms

Dozens of creatine variants — hydrochloride, ethyl ester, buffered creatine, creatine nitrate — are marketed as superior. The evidence does not support these claims: creatine monohydrate remains the most studied form and outperforms or matches all alternatives at a fraction of the cost. Any form must raise muscle phosphocreatine stores to work, and monohydrate does this effectively with excellent tolerance.

Frequently asked questions

Do I need to load creatine?

No. Loading (20 g daily for 5–7 days) saturates muscles faster, but taking 3–5 g daily reaches the same saturation in about three to four weeks with fewer stomach issues. For most people, the daily dose is simpler and equally effective in the long run.

Does creatine cause hair loss?

The concern traces to a single small study from 2009 that found creatine raised DHT levels, a hormone linked to male-pattern baldness. No study has ever shown creatine causes hair loss, and the DHT finding has not been replicated. Genetics remain the main predictor.

Is creatine only for men and bodybuilders?

No. Creatine benefits women, older adults, and team-sport athletes equally, and it is increasingly studied for muscle preservation during aging and recovery from disuse. Dosing does not differ by sex.

The bottom line

Creatine monohydrate is the rare supplement with near-universal scientific agreement: it works for strength, power, and lean mass, with an excellent long-term safety record. Three to five grams daily, consistently, is all most people need.

References

  1. Dietary Supplements for Exercise and Athletic Performance (creatine section). NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/
  2. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation. Journal of the International Society of Sports Nutrition. https://pmc.ncbi.nlm.nih.gov/articles/PMC5469049/
  3. Creatine compound summary. PubChem (National Library of Medicine). https://pubchem.ncbi.nlm.nih.gov/compound/586
  4. Creatine supplementation research literature. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=creatine+monohydrate+supplementation