Creatine

non-nutrient/non-botanical

Best before bed

What is it

Creatine is a nitrogen-containing compound made in the liver, kidneys, and pancreas from the amino acids glycine, arginine, and methionine. It is stored mainly in skeletal muscle as phosphocreatine, where it serves as a rapid-recycling energy reserve for short, intense bursts of work.

How it works

Muscle contraction is powered by ATP, but cells only hold a few seconds' worth at a time. Phosphocreatine acts as a phosphate donor that quickly regenerates ATP from spent ADP, extending the window for high-intensity effort by perhaps eight to twelve seconds before glycolysis takes over. Supplementing creatine raises the size of this reservoir, particularly in people whose baseline stores are below saturation. Beyond muscle energetics, creatine concentrates in brain tissue at lower levels, where it supports cognitive tasks under stress or sleep deprivation. It also pulls water into muscle cells, which contributes both to a modest increase in lean mass on the scale and to cell-signaling effects that promote anabolic adaptation. The body makes about 1 gram per day and obtains another gram or so from animal foods; supplementation simply tops up stores faster and to a higher ceiling than diet alone usually achieves.

Evidence for 5 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Strength and high-intensity exercise performance

Grade A

Strong evidence

Dozens of randomized trials and several meta-analyses show creatine increases maximal strength, power output, and work capacity during repeated short bursts of effort by roughly 5 to 15 percent over placebo. Effects are clearest in trained adults doing resistance training or sprint-interval work, and they accumulate over weeks of consistent use.

Lean mass gain

Grade A

Strong evidence

Creatine added to a resistance training program reliably produces small additional gains in lean body mass, typically 1 to 2 kilograms over 8 to 12 weeks. Part of the increase is intracellular water, but cell-signaling effects and the ability to train at higher volumes also drive real myofiber growth.

Sarcopenia and age-related muscle loss

Grade B

Good evidence

In adults over 60, creatine combined with resistance training has produced greater gains in strength and lean mass than training alone in multiple trials. The effect is meaningful for functional outcomes like chair-stand time and fall risk.

Cognitive performance under stress

Grade C

Moderate evidence

Smaller trials suggest creatine improves short-term memory and reasoning under sleep deprivation or other cognitively taxing conditions, especially in vegetarians who start with lower brain creatine. Effects in well-rested, omnivorous adults are subtle and inconsistent.

Neurodegenerative conditions

Grade D

Mixed evidence

Trials in Parkinson's disease, ALS, and Huntington's have explored creatine for neuroprotection. Results have been disappointing for disease modification, though some symptomatic and functional benefits have been observed. Not a substitute for standard treatment.

4 commercial forms

Creatine monohydrate

Roughly 99 percent absorbed. The reference form used in nearly all positive trials.

The gold standard. Inexpensive, well-studied, effective. Micronized versions dissolve more easily but offer no metabolic advantage.

Creatine HCL (hydrochloride)

More soluble in water; no consistent evidence of greater muscle uptake.

Often marketed as needing smaller doses with less bloating. Real-world studies have not shown meaningful differences in performance outcomes versus monohydrate.

Creatine ethyl ester

Degrades rapidly to creatinine in the stomach; lower effective delivery.

Marketed in the early 2000s as superior; trials have shown it raises muscle creatine less than monohydrate. Generally not recommended.

Buffered creatine (Kre-Alkalyn)

No demonstrated advantage in head-to-head trials with monohydrate.

Sold on the claim that alkaline buffering prevents stomach conversion to creatinine. Independent trials have not confirmed any superiority.

Dosage

There is no RDA. The standard supplementation protocol is 3 to 5 grams per day of creatine monohydrate taken consistently, which saturates muscle stores in roughly three to four weeks. An optional loading phase of 20 grams per day (split into four doses) for five to seven days achieves saturation faster but is not required and increases the chance of mild GI discomfort. Vegetarians and older adults tend to start with lower baseline stores and may notice the biggest changes.

When and how to take it

Timing matters less for creatine than for most supplements because the benefit comes from saturating muscle stores, not from any acute peak. Take 3 to 5 grams once per day, every day, at whatever time you will not forget. Some research suggests modestly better uptake when paired with a carbohydrate or carb-plus-protein meal, which raises insulin and helps shuttle creatine into muscle. Post-workout is a reasonable default, but morning or evening dosing works equally well over weeks. Consistency beats timing. On rest days, still take your usual dose to keep stores saturated.

Food sources

Food	Amount	%DV
Beef (raw)	~2 g per pound	—
Pork	~2.3 g per pound	—
Salmon	~2 g per pound	—
Tuna	~1.8 g per pound	—
Herring	~3 to 4.5 g per pound	—
Chicken	~1.5 g per pound	—

Safety

Creatine monohydrate is among the most thoroughly studied sports supplements, with safety data spanning more than two decades. The most common side effect is short-term water retention, typically 1 to 2 kilograms gained in the first weeks as muscle cells take up extra fluid. Mild stomach upset, cramping, or diarrhea can occur, usually resolved by splitting the dose, taking with food, or switching to micronized monohydrate. Despite persistent rumors, controlled studies have not shown that creatine harms kidney function in healthy adults. It does mildly raise serum creatinine, which is a metabolic byproduct and not a marker of kidney damage in this context, so be sure to tell any clinician interpreting your labs that you supplement. People with pre-existing kidney disease should avoid creatine without medical guidance.

Who should be cautious

People with chronic kidney disease, those on dialysis, and pregnant or breastfeeding women should consult a clinician before starting. Adolescents under 18 have limited long-term safety data, although short-term studies in teen athletes have not flagged concerns. Anyone with a history of compartment syndrome, severe hypertension, or rare metabolic disorders affecting creatine handling should also seek medical input first.

Interactions

Creatine has few clinically significant drug interactions. Combining it with caffeine has been hypothesized to blunt the ergogenic effect, but the evidence is mixed and most users tolerate the combination fine. Nephrotoxic drugs (some NSAIDs, certain antibiotics, cyclosporine) could theoretically compound stress on the kidneys, so people taking these long-term should check with a clinician. Creatine does not interact with most cardiovascular, neurologic, or metabolic medications.

Frequently asked questions

Do I need to do a loading phase?⌄

No. Loading (20 g/day for a week) just saturates muscle stores faster. Taking 3 to 5 g per day reaches the same endpoint in about three to four weeks with less GI risk and no difference in final results.

Will creatine damage my kidneys?⌄

Not in healthy adults. Long-term studies have found no harm to kidney function. It does raise serum creatinine modestly, which can confuse routine labs unless your clinician knows you supplement. Avoid creatine if you have pre-existing kidney disease without medical clearance.

Should I cycle creatine?⌄

No physiological reason to cycle. Muscle stores stay elevated while you supplement and gradually return to baseline over four to six weeks after stopping. Continuous use is fine.

Is creatine only for men?⌄

No. Women respond to creatine the same way, though absolute strength gains scale with starting muscle mass. Women typically gain less visible body weight from water retention because they have less muscle to hold it.

Does creatine cause hair loss?⌄

A single 2009 study in rugby players found a small rise in DHT, a hormone implicated in male pattern baldness, but no actual hair loss was measured. No follow-up trial has replicated even the hormonal finding, and there is no direct evidence creatine causes hair loss.

References

Wikidata: Creatine — Wikidata link
PubChem: Creatine (CID 586) — PubChem link
ChEBI: Creatine (CHEBI:16919) — ChEBI link

Track Creatine with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you're pregnant, breastfeeding, on medications, or managing a chronic condition.