Do you need a loading phase?

No. Loading at 20 g a day for 5-7 days fills the store in one week instead of three or four, but the level reached is the same. Taking 3-5 g a day from the start gets you there just the same, with less stomach upset and using less of the tub.

Does creatine harm the kidneys?

In healthy people there is no evidence of kidney damage: the ISSN position stand reviews it explicitly and concludes it does not. What it does do is raise blood creatinine, a marker used to check the kidneys, and that can muddle a blood test: it is worth telling your doctor you take it. With pre-existing kidney disease, the decision is a medical one.

Do you need to take breaks from it?

No. There is no evidence that cycling it adds anything, and when you stop the store empties within a few weeks and has to be refilled. It is taken continuously.

Does creatine cause bloating or water retention?

It retains water, but inside the muscle cell, not under the skin. That is why the scale goes up without your look or size changing. It is not the subcutaneous bloating people imagine.

Is creatine HCl or Kre-Alkalyn better?

There is no evidence that they beat monohydrate, and they cost considerably more per gram of creatine. Monohydrate is the one with decades of studies. On this site a creatine that does not declare its chemical form also loses points, because not being able to know what is inside is a product defect.

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Creatine · Strong evidence

What creatine is for and what effects it has

The short answer. Creatine monohydrate is the sports supplement with the most evidence behind it. It is not an anabolic steroid or a hormone: it refills the muscle’s phosphocreatine store, which is where the energy for the first ten seconds of a maximal effort comes from. With the store full you do more work in every set, and the muscle comes from that extra work, weeks later.

Several meta-analyses or position stands from scientific societies agree that there is an effect. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.

01 What it does and how much

Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.

Effects of creatine with their source
Effect	How much	Detail
Maximal strength and power	+5 to 15 %	Compared with the same training without supplementing. The margin is bigger the shorter and more explosive the effort. [1]
Total work in sets to failure	+5 to 15 %	More reps before failing with the same weight. This is the real route to gaining more muscle over time: creatine does not build tissue, it lets you train harder. [1]
Repeated sprints	+5 to 15 %	Its best case. In sports with repeated bursts the store has to refill between efforts, and that is where it shows most. [1]
Single sprint	+1 to 5 %	Much less, because a single sprint barely empties the store. [1]
Creatine inside the muscle	+20 to 40 %	The measurable change all the others come from. People starting from a low store (vegetarian or vegan diet) rise more; people whose store is already full rise little, and those are the so-called non-responders. [1]
Weight on the scale	+1 to 2 kg	In the first weeks it is mostly water inside the muscle cell, not fat or new muscle. Your weight goes up without your size going up. [1]

02 How to take it

Dose. 3 to 5 g a day, every day, whether you train or not.
When. The time of day does not matter. What matters is not skipping it: the effect depends on keeping the store full, not on today’s dose.
How long before you notice it. 3 or 4 weeks at 3-5 g a day. With a loading phase, about 7 days.

Details that change the result

The loading phase (20 g a day in 4 doses for 5-7 days) only gets you there sooner. The final level is the same, so it is optional.
Monohydrate. It is the cheap form and the one with the studies: HCl, Kre-Alkalyn and the rest charge more for an advantage that has not been shown.
With water, that is all. No juice, no insulin spike, no need to take it on an empty stomach.
The ISSN explicitly reviews kidney safety and finds no harm in healthy people. With kidney disease involved, that is for a doctor to decide, not a website.

03 When it makes sense and when it does not

Worth it if

Strength, hypertrophy, weightlifting or CrossFit: maximal efforts under half a minute.
Team sports with repeated bursts: football, basketball, rugby, padel.
Vegetarian or vegan diet: you start from a lower store and the response is usually bigger.
Older people doing strength training, where keeping mass and power is the goal.

Not worth it if

Pure long-duration endurance: the gain is marginal and the extra kilo or two of water works against you.
Weight-class sports, in weigh-in week.
If you expect it to replace training or eating enough. It multiplies what you already do; on top of zero it multiplies nothing.

04 Sources

Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.

Kreider RB et al. ISSN position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. doi:10.1186/s12970-017-0173-z

This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.

Questions about creatine

Answered with the data on this page

Do you need a loading phase?: No. Loading at 20 g a day for 5-7 days fills the store in one week instead of three or four, but the level reached is the same. Taking 3-5 g a day from the start gets you there just the same, with less stomach upset and using less of the tub.
Does creatine harm the kidneys?: In healthy people there is no evidence of kidney damage: the ISSN position stand reviews it explicitly and concludes it does not. What it does do is raise blood creatinine, a marker used to check the kidneys, and that can muddle a blood test: it is worth telling your doctor you take it. With pre-existing kidney disease, the decision is a medical one.
Do you need to take breaks from it?: No. There is no evidence that cycling it adds anything, and when you stop the store empties within a few weeks and has to be refilled. It is taken continuously.
Does creatine cause bloating or water retention?: It retains water, but inside the muscle cell, not under the skin. That is why the scale goes up without your look or size changing. It is not the subcutaneous bloating people imagine.
Is creatine HCl or Kre-Alkalyn better?: There is no evidence that they beat monohydrate, and they cost considerably more per gram of creatine. Monohydrate is the one with decades of studies. On this site a creatine that does not declare its chemical form also loses points, because not being able to know what is inside is a product defect.

And now, which to buy

Prices, kept apart from the evidence

This page explains what creatine does and deliberately names no brand. The comparison is the other half: 223 products from 17 stores from €8.95 per kg, sorted by price and by how verifiable their certification is.

See the creatine comparison

Other guides

What each supplement does, with its sources