Creatine definitely works (and it is probably one of the very few legal weightlifting supplements that work if not the only one) but I limit the dose to no more than 1–2 grams a day, which is a fraction of the recommended 5 grams. Despite what they say, 5 grams has side effects, suchs as making the kidneys work too hard and it will result in hair loss if you are genetically prone to it. There may be other long-term side effects as well; so, I wouldn't take more than 1–2 grams a day, which is still more than what you would get by eating a lot of meat and enough for most purposes. Another side effect of creatine is that if you stop taking it, you lose strength dramatically within weeks, which could lead to muscle tears. This is the reason for the common hamstring pulls reported by people taking creatine. Therefore, if you stop taking creatine, decrease the weights and/or workout intensity dramatically in order to avoid injuries.