Creatine monohydrate: what it does, what it doesn't, and how to take it

Creatine monohydrate is the most studied, most effective, and least controversial supplement in the entire sports nutrition catalog. It has more positive trials than any other legal ergogenic aid, costs almost nothing per serving, and has the best long-term safety record of any performance supplement.

It is also one of the most misunderstood. Most users either oversell it as a magic strength pill or undersell it as "just water weight." The truth sits in between, and the practical protocol is simpler than the supplement aisle suggests.

This is the last post in the Workout nutrition cluster opening batch, pairing with the pre-workout meal guide and the post-workout timing post. Together they cover everything the recreational lifter actually needs from training nutrition.

What creatine actually is

Creatine is a naturally occurring compound made from three amino acids (arginine, glycine, methionine). Your body produces about 1g per day on its own, mostly in the liver. You also eat about 1 to 2g per day from red meat and fish if you eat them; vegetarians and vegans get close to zero from food.

Inside muscle, creatine is stored as phosphocreatine, which acts as a rapid energy reservoir for short, intense efforts. When you push a heavy weight or sprint for 5 seconds, your muscles burn through their stored ATP within roughly 1 to 2 seconds, then rely on phosphocreatine to regenerate ATP for the next 6 to 8 seconds. After that, anaerobic glycolysis and aerobic metabolism take over.

Supplementing creatine increases the phosphocreatine pool in muscle by 20 to 40% in most responders. The practical effect: you can do slightly more work before that 6 to 8 second buffer runs out. One more rep at the top of a heavy set. A faster 100m time. A higher peak power output on a sprint.

That is the entire mechanism. The reps add up over weeks and months into measurably more muscle and more strength.

What the evidence actually shows

The Kreider et al. 2017 ISSN position stand on creatine is the consensus document on creatine supplementation. It covers safety, dosing, and effectiveness across 500+ peer-reviewed studies. The headline conclusions:

• Strength gains: 5 to 15% more 1 RM strength over 8 to 12 weeks of training, vs. placebo.
• Lean mass: 1 to 2 kg of additional lean mass on the same training program.
• Repetitions to failure: 5 to 10% more reps at submaximal loads.
• High-intensity exercise capacity: Improved performance on tasks 6 to 30 seconds long.
• Safety: No adverse effects on kidney, liver, or other organ function in healthy users over years of use.

The Antonio et al. 2021 "Common Questions and Misconceptions" review covers the most common confusions: water retention, cycling, kidney concerns, dosing for women, and timing. The TL;DR: most of the worry is misplaced, and the protocol is simpler than commonly described.

The Rae et al. 2003 study on creatine and cognition was the first major trial showing improved working memory and intelligence test scores in vegetarians supplementing with 5g of creatine per day for 6 weeks. Subsequent work has shown the cognitive effect is largest when creatine stores are low (vegetarians, vegans, sleep-deprived adults), modest when stores are already high.

About 20 to 30% of users are "non-responders," meaning their muscle creatine is already near saturation from diet (heavy meat eaters) and the supplement adds little. If you eat a lot of red meat and fish, you may notice less than a vegetarian starting the same protocol.

What creatine does

The benefits that show up reliably in research:

Strength and power

This is the big one. Across the consolidated literature:

• Maximum strength (1 RM bench, squat, deadlift): roughly 8% more than placebo over 8 to 12 weeks.
• Repetitions to failure at 75 to 85% of 1 RM: roughly 8 to 14% more reps.
• Peak power output in sprints and jumps: 3 to 7% improvement.
• Total work done in a session (sets x reps x weight): 10 to 15% more.

These numbers compound. Over a year of training, a lifter on creatine accumulates measurably more total volume than the same lifter without it. More volume drives more adaptation.

Lean mass

Creatine produces 1 to 2 kg of additional lean mass over 8 to 12 weeks of training. About half of this is intracellular water (creatine pulls water into muscle cells, which is part of how it works). The other half is actual contractile muscle tissue, gained from the additional training volume.

Practical implication: expect the scale to jump 1 to 2 kg in the first 2 to 4 weeks of creatine use. That is not body fat. That is muscle hydration plus eventual tissue gain.

Cognitive performance, especially when sleep-deprived

The brain uses creatine the same way muscles do, as an ATP regenerator for energy-demanding tasks. Supplementing creatine modestly improves performance on working memory, complex reasoning, and reaction time tests.

The effect is small in well-rested, well-fed adults. The effect is larger in:

• Vegetarians and vegans (low dietary baseline)
• Sleep-deprived adults
• Older adults (over 65)

A 5g daily dose is enough for the cognitive effect. No different protocol from the muscle dose.

Older adults

For adults over 60, creatine combined with resistance training produces meaningfully better muscle preservation than training alone. The "anabolic resistance" of aging muscle responds well to the higher work capacity creatine enables, plus the modest direct anabolic signaling.

What creatine doesn't do

The supplement industry has expanded creatine's claims well past what evidence supports. The honest list of what creatine does NOT do:

• Burn fat. Creatine is not a fat loss tool. Any "fat burning" associated with creatine is the indirect result of training harder.
• Improve endurance. For events over 30 seconds (10 km running, cycling, long aerobic work), creatine has minimal to no effect. The mechanism is wrong for endurance.
• Cause baldness. This claim comes from one 2009 study showing modestly elevated DHT levels in rugby players. It has never been replicated. The follow-up evidence is consistent with no effect on hair.
• Damage kidneys in healthy users. Decades of trials, including 5-year follow-ups, show no effect on renal function. Elevated serum creatinine (a marker on blood tests) is expected because creatinine is a creatine metabolite; this is not the same as kidney damage.
• Need to be "cycled." There is no evidence that breaks from creatine help. Continuous use at 3 to 5g per day is fine indefinitely.
• Produce "pumps" in a vascular sense. Pumps come from blood flow and glycogen, not creatine. Creatine increases intracellular water (inside muscle cells), which adds visible muscle fullness over weeks, but not the acute pump effect marketed by some pre-workouts.
• Require expensive forms. HCl, kre-alkalyn, magnesium creatine, ethyl ester, and buffered creatine are all more expensive than monohydrate and not more effective. Some are less effective.

How to take creatine

The protocol is simple. Two valid approaches:

Option 1: Daily 5g (recommended for most users)

• 5g of creatine monohydrate per day, every day, with no loading phase.
• Stores saturate over 3 to 4 weeks.
• No GI side effects.
• No weight spike in the first week.

This is the lower-friction protocol and the one I would recommend for any new user.

Option 2: Loading phase (faster saturation)

• 20g per day, split into 4 doses of 5g, for 5 to 7 days.
• Then 3 to 5g per day for maintenance.
• Stores saturate within 7 days.
• Common side effects during loading: bloating, stomach cramps, water retention (1 to 2 kg of fluid weight in the first week).

Loading makes sense only if you want the strength gains to show up within 2 weeks instead of 4. For most lifters, the time saved is not worth the discomfort.

When to take it

Timing barely matters. The current weak evidence slightly favors:

• Post-workout with carbs and protein (best uptake into muscle, theoretically)
• With meals containing some carbohydrate (insulin helps muscle creatine uptake)

But the effect size of timing is small. Daily consistency is the variable that matters. A 5g dose with breakfast every single day beats an inconsistent post-workout dose.

What to mix it with

Cold water, juice, a protein shake, coffee, plain water. The taste is mild and faintly chalky.

Avoid mixing with very hot liquids (boiling water, hot tea). Heat over 60C can degrade creatine to creatinine, the inactive metabolite. Lukewarm coffee is fine; not boiling tea.

Dosing for body size

The 3 to 5g per day recommendation works for most adults from 60 to 100 kg. Outside this range:

• Under 60 kg adults (smaller women, teens): 3g per day is sufficient.
• Over 100 kg adults (larger lifters): 5 to 7g per day may produce slightly better saturation.

The differences are small. 5g per day is a reasonable default for anyone over 50 kg.

Side effects, honestly

The honest side effect list, from common to rare:

• Weight gain of 1 to 3 kg in the first 2 to 4 weeks. This is muscle water, not fat. Reverses if you stop taking creatine.
• Mild stomach upset in 5 to 10% of users at 5g per day. More common at 20g loading doses. Splitting the dose into 2 to 3 smaller servings usually fixes it.
• Mild thirst because creatine pulls water into muscle. Drink 500 ml extra per day to compensate.
• Cramping is a commonly cited "side effect" that has not held up in controlled trials. Hydration solves any cramping that does occur.

What does NOT show up in the literature:

• Kidney problems in healthy users
• Liver problems
• Hair loss
• Hormonal issues
• Long-term metabolic harm

The 30-year safety record is one of the cleanest in supplement research.

Special populations

Vegetarians and vegans

Creatine has the largest effect in this group because dietary baseline is near zero. Both muscle and cognitive gains are typically more noticeable than in heavy meat eaters. 5g per day is sufficient.

Women

The dosing and effects are the same as for men. The "creatine makes women bulky" claim is unfounded. The 1 to 2 kg lean mass gain happens over months of training; it does not produce a visible body composition change overnight or in unwanted places.

Adults over 60

Creatine pairs particularly well with resistance training for older adults, where muscle preservation is the priority. The dose is the same: 3 to 5g per day. The cognitive benefits are also slightly larger in this group.

Teens

Most major sports medicine bodies advise no creatine before age 18 in the absence of supervision. The reason is not safety (the safety record is fine) but the broader principle of building a foundation of training and nutrition before reaching for supplements.

What not to do

• Do not buy expensive proprietary blends. Pure monohydrate is the gold standard. Anything labeled "advanced creatine matrix" with 10 ingredients is overpriced monohydrate plus filler.
• Do not cycle on and off. No evidence supports cycling. Continuous daily use is fine.
• Do not skip days for "rest." Skipped days reduce muscle saturation. Daily consistency is the protocol.
• Do not take it with hot drinks. Heat above 60C degrades creatine over time. Room temperature or cold mixers only.
• Do not expect overnight strength gains. Effects show up within 2 to 4 weeks (with loading) or 3 to 6 weeks (without loading). It is not a pre-workout stimulant; it builds slowly.
• Do not blame creatine for the scale jump. The 1 to 3 kg gain in the first month is intracellular water in muscle. It is not body fat, and it is part of why the supplement works.
• Do not ignore protein and total calories. Creatine amplifies training. Training amplifies the response to calories and protein. If those two are wrong, no supplement compensates.

Bottom line

If you do resistance training and want one supplement worth taking, creatine monohydrate is it. 5g per day, every day, indefinitely. No loading needed, no cycling needed, no expensive forms needed.

Expected results over 8 to 12 weeks of consistent training plus creatine:

• 5 to 15% more strength on compound lifts
• 1 to 2 kg additional lean mass
• More reps before failure on submaximal work
• Modest cognitive benefits, especially under sleep deprivation

Cost: about 30 USD for a 6-month supply of pure monohydrate. There is no other supplement with this combination of evidence, safety, and price-to-effect ratio.

The supplement industry will keep selling you more expensive alternatives and elaborate protocols. The honest answer is: monohydrate, 5g, daily, with whatever liquid you prefer. Done.

For the broader workout nutrition picture, see the pre-workout meal guide and the anabolic window post. For the foundational protein math that anchors all training nutrition, see how much protein per day.