What is the effect size of creatine?

Creatine supplementation makes a difference in the low single digits, which can certainly compound over time. If you are not performing at a level, where single digit performance increases are noticeable, you will not notice any benefit beyond placebo on shorter timeframes. If you are only half-assing your training, show up only randomly or do not record the weights you are using, there is little use of creatine for you.

What is creatine?

Creatine is not quite an amino acid, but often wrongly counted towards the essential amino acids. Essential means that the body can produce it in small quantities, because it is of such importance. While not an amino acid, creatine is essential and some organs like the kidneys have the ability synthesize creatine from a bunch of amino acids. While this natural creatine production is sufficient to keep you alive, it is in most cases not at a level necessary for optimal performance.

What does creatine do in tissue?

When cells need energy, they convert adenosin triphosphate (ATP), i.e. some molecule with three phosphorus attachments, into adenosin diphosphate (ADP), i.e. some molecule with two phosphorus attachments. This process frees up energy, which then can be used by the cell, for pure survival or any process it has to do, or, most importantly, muscle contraction.

Creatine (CR) can bind a phosphor molecule, turning it in Creatine phosphate (PCr). Stored in the tissue, this molecule can donate the phosphor molecule to ADP, turning it back into ATP.

There are other methods to refuel your ATP stores, but the conversion PCr to Cr is a very fast mechanism (you only shift one molecule around).

Creatine sources

Unless you eat daily large amounts (if you don't measure it in kilos, it's a small amount) of meat, the best source would be pure creatine. It's cheap and easily synthetized, so even if you are vegan, you can just supplement the cheapest creatine you find.

Does creatine help build muscle and strength?

It helps you mainly to train harder (i.e. bigger per session volume), without interfering too much with possible growth signalling pathways. More training means at least more strength gains, and in the case for creatine probably also more muscle gains over time. Contrast this with stuff like beta-alanine, which allows you to train more, but by blunting possible growth signalling pathways to a point where it seems to counterbalance the benefits (at least for muscle growth).

Does creatine improve endurance?

It provides energy, so yes. I have no idea whether or not this is good or bad for long term training.

Does creatine have mental benefits?

Possibly there might be some benefits for mental performance, mainly in the sense of returning your performance to normal levels. If you do not eat a lot of meat (again, up to kilos of meat every day), you might not be able to concentrate as long as with sufficient meat consumption.

At least that is what one study suggests. Overall the evidence seems weak at best and if you have to look at your phone every half hour or so, there are probably better ways to improve your mental game.

Is creatine healthy?

With regards to safety, creatine is the most researched supplement and ill effects were only observed in persons with pre-existing conditions, especially those affecting the kidneys or liver. So you SHOULD consult with your physician, but if you know you're healthy, you are good to go.

Overall research indicates beneficial effects for both cardiovascular and mental health, e.g. depression and anxiety. However at this point it is too early to recommend creatine for these purposes and more research has to be done.

Studies showing increases in any hormones or growth factors do not seem to hold their water, or report only physiologically irrelevant increases.

Does creatine impair natural creatine production?

As you reach saturation, your body decreases the production of creatine, since that would only be wasted effort. However, if you stop supplementing creatine or have an increased demand, your natural production will work again as before.

Does creatine increase water retention?

Yes, there is some increased intramuscular water retention. Mostly it is due to the water needed to store the additional PCr in the muscle, comparable to the increased water retention when storing more glycogen. There also sometimes seems to be a transient increase in intramuscular water retention when starting supplementation, which goes back once you are accustomed to it.

As this water retention is intramuscular, it is a good thing, since this alone increases the pennation angle of your muscle fibers, thereby increasing strength to a small degree. Unless of course, you are dependent on making weight or are performing in a sport where increased bodyweight is detrimental. Then this added weight might be a disadvantage, especially if do not need to rely on the PCr energy system.

How much creatine?

The general recommendation is 3 to 10 gram per day, everyday, forever.

Depending on your bodyweight and exercise volume, you should use the lower or higher end of the range, with the typical 90kg trainee sitting at 5g.

Some people suggest you need far less than this, but usually these people do not lift or are very small. Some people also might not need as much, as they are already eating large amounts of meat or have a naturally high production.

There are also some people suggesting you might far more than this, up to 0.3g per kg of bodyweight. I traced it back to the infamous John Kiefer, who has a history of over-interpreting study results, so I would not say that this approach is scientifically backed. However, creatine is cheap and you could just try it out. Aside from Kiefer, the people reporting success with that are on the other hand very large specimen lifting heavy and lifting a lot.

There is this common myth of loading protocols and cycling creatine, which comes down to the limitations of study design. It is hard to compare a person taking creatine for life to that same person not doing it, so you study the person without creatine, with creatine and again without creatine. However, if you belong to a population where additional bodyweight is of detriment during competition, you might want to use creatine only during the preparation phase, allowing for harder training. Then also loading protocols with more than the daily 5g might be beneficial, as you only have so many weeks of training before you, in contrast to the lifelong lifter where two weeks more or less do not matter in the grand scheme of things.

Creatine and caffeine?

Both creatine and caffeine are good. There is again some myth about not consuming creatine and caffeine at the same time, but I was unable to find anything supporting this. As far as I know, people tried to figure out whether creatine plus caffeine had a synergistic effect, but it did not. And then somehow people happened and "there is no additional benefit from consuming the two simultaneously" changed into "never take the two together".

How to take creatine?

The easiest way is to just dissolve creatine in some cold beverage. You do not want to add creatine to hot beverages, as this can again break it down, just as in cooked meat versus raw meat. Also you do not want it to sit too long in solution, as this also can break it down, but this is more in the time frame of several hours and not minutes.

An easy way is to just put some of it into your drinking bottle and let it just go in solution as you drink and refill the bottle.

Some people report stomach issues when taking large amounts in a single setting, either space those out or ingest carbohydrates along with it.

Timing of intake?

There does not seem to be a acute benefit of creatine intake and as creatine in stored in your favorite tissue, you can just take it whenever it is convenient for you. Especially it is neither necessary nor beneficial to take it in the workout window.

Closing words

I will keep this file updated as I learn more about creatine, or find me answering other questions again and again, and I am very open to suggestions.