Creatine

What It Is

Creatine is a naturally occurring compound synthesized in the liver and kidneys from the amino acids arginine, glycine, and methionine. About 95% of the body's creatine is stored in skeletal muscle as phosphocreatine — a rapidly available energy reserve for high-intensity efforts. It is also found in small amounts in the brain.

Creatine monohydrate is the standard supplemental form. It is the most studied, least expensive, and most effective formulation. Claims that other forms (ethyl ester, buffered creatine, etc.) are superior are not supported by the evidence.

What the Evidence Shows

Creatine has one of the deepest evidence bases of any sports and aging supplement:

• Muscle strength and power: Multiple meta-analyses confirm that creatine supplementation, combined with resistance training, produces significantly greater gains in strength and lean mass than training alone — across age groups including older adults.
• Muscle preservation without training: Some evidence suggests creatine may help attenuate muscle loss during periods of reduced activity or immobilization, though training remains the primary lever.
• Cognitive function: Emerging research — particularly in older adults and vegetarians who have lower baseline creatine stores — suggests benefits to memory, processing speed, and executive function. The brain uses creatine for the same ATP recycling function as muscle.
• Bone health: Some research suggests creatine may support bone mineral density, though the evidence is less consistent than the muscle data.

Dosing

Standard maintenance dose: 3–5g daily. Timing does not matter significantly — consistency matters more.

Loading phase (optional): 20g/day split into 4 doses for 5–7 days, followed by 3–5g maintenance. Loading reaches saturation faster but is not necessary — regular dosing achieves the same endpoint in 3–4 weeks. Loading may cause temporary water retention and GI discomfort in some people.

With age: Some researchers suggest older adults may benefit from the higher end of the range (5g daily) due to lower baseline muscle creatine stores and anabolic resistance.

Safety Profile

Creatine monohydrate has been studied extensively for over 30 years. It is safe for long-term use in healthy individuals. Concerns about kidney damage or hair loss have not been supported by controlled research at standard doses. Creatine does cause a mild, benign increase in serum creatinine — a marker used in kidney function tests — which can be misinterpreted but does not reflect kidney damage.

People with pre-existing kidney disease should consult their physician before supplementing, as a precaution.

Practical Notes

• Creatine monohydrate powder is the most economical form. Unflavored versions mix easily into water, coffee, or a shake.
• It does not need to be cycled.
• It is not a stimulant and has no effect on sleep.
• Vegetarians and vegans typically have lower baseline muscle creatine stores and tend to show the strongest response to supplementation.