Creatine Loading Phase: 6 Essential Facts and Risks
Creatine Loading Phase: 6 Essential Facts and Risks
A creatine loading phase is a short period of high intake, classically 20 g a day for about 6 days, used to fill muscle creatine stores quickly before dropping to a small daily dose. A loading phase creatine protocol works, and it is optional. In the study that defined the protocol, Hultman and colleagues measured the same 20 percent rise in muscle creatine from 3 g a day, it simply took 28 days instead of 6.
Educational content only. This page reports what published trials measured. It is not medical advice and it is not a dosing prescription. If you have kidney disease, take medication that affects kidney function, or are under 18, talk to a clinician before using creatine at any dose.
Supplements Editor · Updated September 2026
Three numbers that settle the argument
Hultman and colleagues measured a rise of about 20 percent in muscle total creatine after 6 days at 20 g a day. That is the fast road, and it is the origin of every loading instruction printed on a tub.
The same paper found a similar 20 percent rise after 28 days at 3 g a day. The destination is identical. The creatine loading phase only changes how soon you arrive.
Ostojic and colleagues recorded diarrhoea in 55.6 percent of athletes taking 10 g at once, against 28.6 percent when the same amount was split into two 5 g doses. The side effects of a creatine loading phase are mostly a dose size problem.
Every figure on this page comes from a published abstract checked against PubMed. Where a number is common gym advice rather than a measured result, the text says so.
What this guide covers
The protocol itself. What a creatine loading phase is, where the 20 g figure came from and what the maintenance dose was in the original work.
Loading against no loading. The creatine loading phase and the slow road side by side: days to saturation, grams used, side effect risk.
The risks people search for. Water weight, stomach trouble, kidneys and cramps, each against the trial that measured it.
Who should bother. Responders and non responders, cycling, washout, and a plain verdict on when a creatine loading phase earns its place.
What a creatine loading phase actually is
Muscle holds a limited pool of creatine, and supplementation raises that pool until it is full. The creatine loading phase is simply a way of filling it faster. Harris and colleagues first showed in 1992 that repeated 5 g doses across the day raised muscle creatine in resting and exercised muscle, and Hultman and colleagues turned that into the protocol still printed on tubs today.
| Approach | Daily dose | How it is taken | Days to about 20 percent rise | Creatine used in 28 days | Status |
|---|---|---|---|---|---|
| Creatine loading phase | 20 g, then 2 g | 4 doses of 5 g for 6 days, then 2 g daily | 6 | 164 g | ● measured |
| Low dose, no loading | 3 g | One dose daily | 28 | 84 g | ● measured |
| Typical label dose, no loading | 5 g | One scoop daily | Between the two | 140 g | ● common practice |
Two details from the original paper rarely make it into gym advice. First, once stores were full, 2 g a day was enough to hold them there for a further 30 days. Second, when supplementation stopped entirely, muscle creatine drifted back to the starting value over roughly 30 days. A creatine loading phase is therefore a one time event at the start, not something to repeat every month.
If you are still choosing a product, the form matters less than the marketing suggests. Our breakdown of creatine HCL covers how the alternatives compare with plain monohydrate, which is the form used in almost every creatine loading phase study.
Is creatine loading necessary
No. Antonio and colleagues list it among the common misconceptions in their evidence review for the International Society of Sports Nutrition, which asks directly whether a loading phase is required. The answer in the data is that a creatine loading phase is a shortcut, not a requirement. Both roads end at the same muscle creatine level.
With a loading phase
Hultman and colleagues, 20 g a day for 6 days, about 20 percent rise in muscle total creatine.
Without loading
Same study, 3 g a day for 28 days, a similar but more gradual 20 percent rise. The day 7 figure is a straight line estimate.
So the decision is about patience and tolerance, not about results. If you have a competition or a training block starting inside the next month, the three weeks a creatine loading phase saves do matter. If you do not, the slower road costs half the powder and spares your stomach.
How long until creatine is fully working
The chart below draws both protocols from the two endpoints Hultman and colleagues actually measured: full stores at day 6 with loading, and at day 28 on 3 g a day. The lines between those points are schematic straight lines, because the study did not biopsy every day. What matters is the shape. The creatine loading phase is a wall, the daily dose is a ramp, and they meet.
Where are you on each road
A straight line estimate between the measured endpoints of Hultman and colleagues: full at day 6 with 20 g a day, full at day 28 with 3 g a day. Individual response varies. Educational estimate, not medical advice.
Performance follows the stores. In the most recent pooled analysis, Kazeminasab and colleagues combined 69 studies and 1,937 participants and found that creatine plus resistance training added 1.43 kg to bench and chest press strength and 5.64 kg to squat strength over training alone. None of that depends on whether a creatine loading phase filled the tank or a slow daily dose did.
Creatine loading phase side effects, measured
Stomach trouble scales with dose size
55.6%Ostojic and colleagues gave athletes 10 g as a single dose or as two 5 g doses. Diarrhoea hit 55.6 percent of the single dose group against 28.6 percent with split doses, and the split group did not differ from placebo. Four small servings is the reason a creatine loading phase is prescribed the way it is.
The scale jumps, and it is water
WaterPowers and colleagues found creatine supplementation raised muscle creatine, body mass and total body water, while the distribution of fluid between compartments did not change. The early gain during a creatine loading phase is water held with creatine inside the system, not fat.
Kidneys: no damage signal in pooled trials
No signalA meta analysis by de Souza e Silva and colleagues concluded that creatine supplementation does not induce renal damage in the amounts and durations studied. Hultman and colleagues did see urinary creatinine excretion rise during supplementation, since creatinine is the breakdown product of creatine, which is worth telling whoever orders your bloodwork.
Cramps and dehydration are on the myth list
MythAntonio and colleagues address dehydration and muscle cramping directly in their review of common creatine misconceptions, alongside hair loss and fat gain. None of them is supported as a consistent effect of supplementation in the controlled evidence they examined.
Not everyone responds
5 of 8Greenhaff and colleagues loaded eight subjects with 20 g a day for 5 days. Five showed a substantial rise in muscle total creatine, averaging 25 percent. Three barely moved. A creatine loading phase cannot raise stores that are already close to full.
Loading burns through the tub
164 gA creatine loading phase on the Hultman protocol uses 164 g of creatine in the first 28 days against 84 g on the 3 g road. That is nearly double the powder for the same end point, which is a side effect on your wallet rather than your body. If cost matters to you, our creatine gummies vs powder comparison shows what each format charges per 5 g.
Diarrhoea reported in the Ostojic trial, by how the creatine was dosed
The placebo figure is the detail to notice. More than a third of athletes reported diarrhoea on no creatine at all, so a share of what gets blamed on the creatine loading phase is ordinary training life.
Why loading works better for some people
The response to a creatine loading phase depends on how empty the tank was to begin with. In the Greenhaff study the five responders gained 19 to 35 mmol per kg of dry muscle, while the remaining three gained only 8 to 9 mmol per kg, a rise of 5 to 7 percent, and showed no improvement in phosphocreatine resynthesis. The usual explanation is a starting level already close to the ceiling.
What you take it with matters too. Green and colleagues found that taking creatine with a large carbohydrate load increased the rise in muscle total creatine by 60 percent compared with creatine alone. Preen and colleagues later reported that a much smaller glucose intake than previously used was potentially the most effective way to raise muscle creatine during loading.
The practical reading is modest: take each dose with a meal. Whether that meal falls before or after training is a smaller question, covered in our guide to creatine before or after a workout. A creatine loading phase does not need a sugar drink, and certainly not one four times a day for a week.
Do you need to cycle creatine or reload
There is no trial showing that cycling on and off, or repeating the creatine loading phase, improves anything. What the data does show is how slowly the stores empty. In the Hultman study muscle creatine took about 30 days without supplementation to return to baseline. Preen and colleagues found that 6 weeks after loading, muscle creatine in the group taking nothing had still not fully returned to its starting level.
Missed a few days. Nothing to fix. Stores fall over weeks, not days, so carry on with the normal daily dose.
Stopped for a month or more. You are back near baseline, and a second creatine loading phase is a legitimate way to refill quickly if timing matters.
Staying on long term. Vandenberghe and colleagues kept young women on low dose creatine through 10 weeks of detraining and muscle phosphocreatine, strength and fat free mass stayed higher than placebo. A small daily dose holds the gain.
Five loading phase creatine mistakes
1. Taking the day's 20 g in one or two hits. The stomach data is clear that dose size drives the problem. A creatine loading phase is four servings of 5 g for a reason.
2. Running the creatine loading phase for two weeks. Stores were full at day 6 in the original work. Every high dose day after that is expensive urine.
3. Repeating the creatine loading phase every month. Stores take around 30 days without any creatine to empty. If you never stopped, there is nothing to reload.
4. Reading the week 1 weight gain as fat, or as muscle. During a creatine loading phase it is mostly water. Judge progress on strength and on the mirror after a month.
5. Keeping the loading dose as the daily dose. Once stores are full, a small maintenance dose holds them. The creatine loading phase ends, and that is the point of it.
So, should you do a creatine loading phase
It depends on your calendar and your stomach, not on results. Both protocols reached the same muscle creatine level in the study that compared them, so the only thing a creatine loading phase buys is about three weeks.
- You have a competition, test or training block starting within the next four weeks.
- You are returning after a month or more off creatine and want full stores quickly.
- You tolerate 5 g servings without stomach trouble.
- You are happy to split the dose into four servings with meals for a week.
- You are in no hurry and will still be training a month from now.
- You have a sensitive stomach or a history of digestive trouble with supplements.
- You need to make a weight class and cannot absorb a sudden jump on the scale.
- You would rather not use twice the powder for the same result.
Kreider and colleagues, writing the International Society of Sports Nutrition position stand, note that studies have consistently shown creatine supplementation raises intramuscular creatine, which may help explain the improvements seen in high intensity exercise performance. That finding is about taking it consistently. How you start is a detail.
Common questions
Do I need a creatine loading phase?
No. In the study that defined the protocol, 3 g a day for 28 days raised muscle creatine by about the same 20 percent as 20 g a day for 6 days. A creatine loading phase gets you to full stores roughly three weeks sooner and changes nothing about where you end up.
Is creatine loading necessary for results?
It is not. The evidence review by Antonio and colleagues lists the idea that loading is required among common creatine misconceptions. Strength and lean mass benefits come from having full stores and training hard, and a steady daily dose fills them without any loading at all.
How long does a loading phase take?
A creatine loading phase lasts about 6 days in the original Hultman protocol, at 20 g a day split into four 5 g doses. Greenhaff and colleagues used 5 days at the same dose. There is no measured benefit to extending it, because the muscle has a ceiling and extra creatine beyond it is excreted.
Does creatine loading cause bloating or water weight?
A creatine loading phase raises body water. Powers and colleagues measured increases in muscle creatine, body mass and total body water with supplementation, with no change in how fluid was distributed. The week 1 jump on the scale during loading is that water, and it is expected rather than harmful.
How much creatine should I take after loading?
In the Hultman study 2 g a day was enough to hold the loaded level for a further 30 days. Most tubs suggest a larger scoop, commonly 5 g, which is popular practice rather than a measured requirement. Either way the dose after loading is small and taken once daily.
Should I split the loading dose?
Yes. In the Ostojic trial a single 10 g dose produced diarrhoea in 55.6 percent of athletes, while two 5 g doses produced it in 28.6 percent, no different from placebo. Four servings of 5 g with meals is the standard way to run a creatine loading phase.
Is a loading phase bad for your kidneys?
Pooled trial data does not show it. A meta analysis by de Souza e Silva and colleagues concluded that creatine supplementation does not induce renal damage in the amounts and durations studied. People with existing kidney disease were not the population studied and should ask a clinician first.
Do I have to load again after a break?
Only after a long one. Muscle creatine took around 30 days to return to baseline once supplementation stopped, and another trial found it still slightly raised after 6 weeks. After a short break just resume the daily dose. After a month or more, a second creatine loading phase is a reasonable shortcut.
References
More on creatine and performance
Final Educational Note
This article is for educational purposes and does not constitute medical advice. Creatine response depends on diet, muscle mass, kidney function and medical history, and the trials described here were run in healthy adults. Do not start a loading protocol, change a dose or interpret a blood test based solely on general guidance from any website, including this one. If you have kidney disease, take medication that affects the kidneys, are pregnant or are under 18, a clinician should make the call.
MuscleScience does not sell creatine, supplements or medical services. We have no financial relationship with any supplement manufacturer. The goal of this article is to show what the loading studies measured so you can decide how to start. For more guides, see the supplements hub.
