Five grams is one of those numbers that has become almost inseparable from creatine.

Buy a container of creatine monohydrate and the scoop will probably hold about five grams. Ask someone at the gym how much they take and the answer will probably be the same. It is simple, inexpensive, and supported by decades of research.

I take fifteen grams.

When I travel under conditions likely to involve meaningful sleep deprivation, I increase that to twenty-five grams total for the day.

The obvious question is whether I get anything from those additional grams or merely produce more expensive urine. The answer depends on which part of the body we are discussing.

Muscle is the easy part

Creatine helps replenish adenosine triphosphate, or ATP: the immediate energy currency used by cells. It does this through the phosphocreatine system, which acts as a rapidly accessible energy buffer.

That matters during repeated high-intensity efforts. A hard set of squats, a sprint, or an explosive movement can consume ATP faster than the body can replace it through slower metabolic pathways. Stored phosphocreatine helps bridge that gap.

This is the traditional case for creatine, and it is a strong one. But skeletal muscle has a storage limit.

In a classic human experiment, researchers gave participants 20 g/day for six days. Muscle creatine increased by approximately 20%. Another group reached a similar elevation with 3 g/day for 28 days. The larger dose filled the reservoir faster; it did not create an infinitely larger reservoir. After loading, 2 g/day maintained the elevation in that experiment. Read the muscle-loading study.

That changes the question. If the only objective is to saturate muscle, taking three times as much does not produce three times as much stored creatine. Once the reservoir is full, additional intake encounters diminishing returns.

At the time of this note, I weighed approximately 98.5 kg. My 15 g daily intake worked out to roughly 0.15 g/kg. Several resistance-training studies have used about 0.1 g/kg/day, which would put me near 10 g. One such trial found that creatine combined with resistance training produced greater gains in muscle mass than training alone. Read the weight-adjusted trial.

If muscle were my only consideration, I would have difficulty making a strong case for 15 g instead of something closer to 5–10 g.

Muscle is not my only consideration.

The brain is a harder reservoir to fill

The brain also depends on ATP. Neurons need energy to maintain electrical gradients, communicate, process information, and recover from sustained activity.

It seems logical that supplemental creatine could support this system in the same way it supports working muscle. The complication is delivery.

Skeletal muscle readily accumulates dietary creatine. The brain is more guarded. Creatine must cross the blood-brain barrier through a transporter with limited capacity, so brain creatine changes more slowly and less predictably.

In a small magnetic-resonance spectroscopy study, six healthy volunteers consumed 20 g/day for four weeks. Average brain creatine increased by 8.7%, but individual responses varied from 3.5% to 13.3%. The two largest male participants showed the smallest increases. Read the brain-creatine study.

That is interesting for two reasons. It demonstrates that oral creatine can raise creatine inside the human brain, and it suggests a fixed five-gram dose may not create the same exposure in every person—particularly when body size differs substantially.

An increase in brain creatine is not the same as an improvement in cognition.

A six-week randomized study compared 10 g, 20 g, and placebo in 30 healthy young adults. Neither creatine group significantly outperformed placebo on the cognitive tests. The 20 g group also reported some gas and bloating. Read the dose-response study.

This is where the argument for my 15 g baseline must remain precise.

I cannot say 15 g has been demonstrated to improve cognition in a healthy, rested person. It has not. I also cannot say it is an optimal brain dose. That experiment has not been done.

What I can say is that higher intake has raised brain creatine, responses vary between people, and larger individuals may obtain a smaller increase from the same fixed dose.

My 15 g baseline is therefore an intentional choice under uncertainty. I divide it into three 5 g servings. It comfortably covers muscle requirements and gives me a plausible chance of greater brain exposure than a conventional maintenance dose.

That is a rationale, not a proven cognitive result.

Then sleep deprivation enters the story.

A rested brain and a tired brain are different experiments

Many interventions appear unimpressive when the system being tested already functions normally. Give more fuel to a machine that has plenty and nothing obvious may happen. Place the same machine under sustained demand and reserve becomes more important.

Sleep deprivation is a form of energetic stress. Attention slows. Reaction time deteriorates. Working memory becomes less reliable. Tasks requiring the prefrontal cortex become harder.

Under those conditions, creatine’s effect becomes more visible.

In a small double-blind study, participants took 20 g/day for seven days before undergoing 24 hours of sleep deprivation with intermittent exercise. Compared with placebo, the creatine group experienced less deterioration in random-movement generation, choice reaction time, balance, and mood. Benefits were most apparent in tasks placing substantial demand on the prefrontal cortex. Read the 2006 study.

A related experiment extended sleep deprivation to 36 hours. The creatine group performed better on a central-executive task at the final measurement, although most other outcomes did not differ. Read the 2007 study.

Another study enrolled ten professional rugby players who had obtained only three to five hours of sleep. Acute creatine doses of 50 or 100 mg/kg—approximately 4.5 and 9 g for those players—improved repeated passing accuracy compared with placebo. It was a very small study, but it suggested an acute effect when sleep loss creates an energy deficit. Read the rugby crossover study.

These early studies were small and not uniform, but they pointed toward a pattern:

Creatine’s cognitive value may become easier to detect when the brain is under metabolic stress.

The acute high-dose experiments

In 2024, researchers conducted a randomized, double-blind crossover experiment with 15 healthy adults. Each participant completed two sleep-deprivation sessions. In one, the participant received placebo. In the other, a single creatine dose of 0.35 g/kg.

The researchers used magnetic-resonance spectroscopy to observe cerebral creatine and high-energy phosphate metabolism during 21 hours of sleep deprivation. The dose changed measured brain metabolism, reduced subjective fatigue, and partially countered deterioration in memory, processing speed, and psychomotor vigilance. The strongest cognitive effects appeared about four hours after administration and persisted for as long as nine hours. All 15 participants completed the experiment, and the researchers reported no gastric discomfort. Read the 2024 study.

That was a fascinating result, but still one small experiment in young adults.

In 2026, the same general model was tested in 29 healthy participants using a lower single dose of 0.2 g/kg. Creatine reduced sleep-deprivation-related deterioration in logical and numerical tasks, language-processing speed, and psychomotor vigilance. Improvements reached approximately 12% on some measurements. The lower dose still worked, although effects were less pronounced than those observed with 0.35 g/kg. Read the 2026 replication.

We now have two controlled experiments suggesting that a single, weight-adjusted dose can reduce selected cognitive consequences of sleep deprivation.

That is where my travel protocol comes from.

Why I increase to 25 grams

At my body weight, the two recent study doses translate to:

  • 0.2 g/kg: approximately 19.7 g
  • My travel dose: 25 g, or approximately 0.254 g/kg
  • 0.35 g/kg: approximately 34.5 g

My 25 g total sits between the two research protocols. I do not take my normal 15 g and add another 25 g; I increase the total from 15 to 25 g.

I also do not use the higher amount simply because I board an airplane. A short daytime flight after normal sleep does not create the condition studied in these experiments.

The use case is sleep-deprived travel: an overnight flight, substantially disrupted sleep, extended wakefulness, or a long travel day followed by work that requires attention and clear thinking.

No study has shown that creatine treats jet lag. Jet lag is a circadian problem created by crossing time zones faster than the biological clock can adjust. Creatine has not been shown to reset that clock.

The evidence supports a narrower proposition: creatine may reduce some cognitive deterioration caused by sleep loss. Travel happens to be one circumstance in which that problem repeatedly appears.

One dose or several remains unresolved

The recent sleep-deprivation studies administered creatine as a single large dose. That may be important.

The proposed mechanism depends partly on creating a high concentration outside brain cells while they experience elevated energy demand. A temporary increase in circulating creatine could help overcome the brain’s normally limited uptake.

Splitting 25 g into separate servings may be more comfortable, but it may not produce the same plasma peak or acute cerebral effect. Large servings, on the other hand, can cause gastrointestinal problems.

In a study of 59 male soccer players, taking 10 g in one serving produced significantly more diarrhea than dividing the same daily amount into two 5 g servings. Read the gastrointestinal study.

That creates a practical dilemma. The protocol most similar to the cognitive experiments may also be more likely to create gastrointestinal distress—hardly an attractive trade during travel.

For now, I treat tolerability as part of the experiment. The literature provides a plausible dose range and time course. It does not provide a universally comfortable travel protocol.

The experiment I am actually running

My daily 15 g and 25 g travel total should not be treated as one established protocol. They ask two related but different questions.

The daily amount asks:

Does maintaining a higher creatine intake provide anything I can detect beyond the muscle benefits already expected from creatine?

The travel amount asks:

When sleep deprivation is unavoidable, does a temporary increase help preserve my ability to think and work?

The second question is easier to test. On comparable travel days, I can track:

  • Sleep obtained during the preceding 24 hours
  • Flight duration and time-zone change
  • Creatine timing and total intake
  • Caffeine intake
  • Subjective sleepiness
  • Ability to perform focused work after arrival
  • Reaction time on a short psychomotor-vigilance test
  • Gastrointestinal response

The comparison that matters is not 25 g versus nothing. I already consume 15 g every day. The useful comparison is 15 versus 25 g under similar sleep-deprived conditions.

The controlled studies do not tell us whether someone already consuming a high daily amount receives an additional acute benefit from increasing it. My baseline brain and muscle creatine may already be elevated, reducing the effect of the extra ten grams. That is one of the experiment’s central uncertainties.

Safety and monitoring

Creatine has a reassuring safety record in people without underlying kidney disease, but chronic research at exactly 15 g/day is limited.

Approximately 10 g/day for three months did not worsen cystatin C or other renal markers in healthy men undergoing exercise training. Read the kidney-function trial.

In a much larger clinical trial, 1,741 people with Parkinson’s disease received 10 g/day or placebo. Median follow-up was about four years, and researchers found no detectable difference in adverse or serious adverse events by body system. Creatine did not slow Parkinson’s progression, but the trial supplied useful long-term safety information. Read the long-term trial.

At doses reaching 40 g/day, gastrointestinal adverse events became significantly more common. More is not biologically free. Read the high-dose CREST-E trial.

Supplemental creatine can also complicate interpretation of serum creatinine, particularly in someone with substantial muscle mass and frequent resistance training. I therefore consider cystatin C and urine albumin alongside conventional creatinine-based kidney estimates.

The travel dose does not replace sleep, hydration, food, or movement during a long flight. It is an attempt to preserve part of an energy-buffering system when sleep loss cannot be avoided.

Where I currently stand

The case for my two amounts is not equally strong.

Fifteen grams per day is my deliberately high baseline. It comfortably covers muscle requirements and has a plausible brain-exposure rationale, but the literature does not demonstrate that it improves cognition more than 5 or 10 g in a healthy, rested person.

The 25 g travel total has more direct support. Two controlled experiments found that single, weight-adjusted doses between 0.2 and 0.35 g/kg reduced selected aspects of cognitive deterioration during sleep deprivation. At my body weight, 25 g falls between those doses.

That does not make it a jet-lag treatment. It does not establish 25 g as optimal. It does not tell us whether increasing from an already-high 15 g baseline produces the same benefit observed when creatine was compared with placebo.

But it is no longer an idea built only from mechanism. There is a small but coherent line of human evidence behind it—and a clear N=1 question worth testing.