Hektore

First and foremost: creatine is not a steroid. It just isn't. Creatine is a molecule that stores energy in order to help maintain ATP balance in your muscles in the form of creatine phosphate. Most people know that ATP is the primary energy courier in cells, a few less people know that ATP is essential for nucleic acid sythesis as well. This means if you ever were to run out of ATP in a cell, that cell would no longer be able to synthesize proteins (no mRNA = no proteins) and you would be big damn trouble because that cell is going to die in a big damn hurry.

This is a problem in muscle cells because your muscles often have a high demand for ATP placed on them, since they require it to 're-cock' the myosin heads and continue to work. What your muscles do, so that they don't run out of ATP, is store energy to make more ATP in the form of creatine phosphate, as well as break down fats and/or carbs depending on the muscle type you are talking about(weight lifting is almost entirely anaerobic so the muscle breaks down carbs for more ATP). Creatine phosphate is actually higher in energy than ATP, so when your ATP starts to drop off there is an enzyme that transfers the phosphate group back from creatine phosphate to the used ATP(ADP) to make it ATP again. This is so your ATP levels stay high enough that the cell can continue to function. When both your ATP and creatine phosphate get too low your body won't let you use the muscle anymore so that you don't run entirely out of ATP.

This is the point where muscles fail, and won't contract anymore. Your body will need time now to regenerate it's ATP and creatine phosphate stores(Along with a slew of other things). So, think about it logically, more creatine means more creatine phosphate means you can lift weights longer. Correct to a certain degree, the degree we are talking about thought is maybe the difference between getting the last rep and not getting it, or getting one more rep. On the day. What it doesn't do is make you stronger, it may help you get stronger marginally faster(what you gain from that extra .5-1 rep), but the difference is negligible compared to if you just work out honestly, especially if you are already working out honestly. (Most people I know when they start taking any supplement slack off a bit because they somehow think the supplement will make up the difference, doesn't mean you will just a common phenomena I've noticed.)

Also there need to be two major problems with taking creatine that should be considered. First is that your body has mechanisms built in that will cause the storage of more creatine without any outside help. When you take creatine in supplement form you shortcut those mechanism so that your body doesn't get them rolling in high gear naturally, the way it should be. When you stop taking creatine you regress really quickly because your body hasn't had to make the creatine on it's own because the cellular machinery has been interfered with. It's the exact same problem that happens with steroids except steroids have all sorts of effects so everyone knows that they're terrible for you and should not be taken without supervision by a doctor. Also creatine is amazingly good at making your cells retain water, which makes you look bigger, but that goes away as soon as you stop taking it and can lead to dehydration if you aren't incredibly careful when you start.

Secondly, and most importantly it's easy to take too much creatine which is really bad for you. All the extra creatine has to be broken down then filtered out by your kidneys which can (and has at least once) lead to acute kidney failure. Bad news bears for you if that happens. As always, before you start taking any supplements, talk to your doctor, then maybe to a physiologist, then at least another doctor or two before you decide on taking anything. Don't ask a high school football coach, the big guy at the gym, the guy in charge of the gym or the guy at the GNC. They can't tell you with any more certainty than we can because don't know unless they also happen to be a doctor/physiologist (same as us).

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The advantage law is the best law in rugby, because it lets you ignore all the others for the good of the game.