There is only so much creatine your muscles can take so you pee out the rest, basically. Dave is also right the 1kg was most likely water retention as creatine draws extra Water into the cells, which would also indicate that you have increased your intramuscular creatine stores. And Dave as creatine is a food supplement and not a drug it does not have to be regulated. It can be a good boost to some but it’s definately never going to beat hard training and good eating it should just compliment it to help you train harder for just that little bit longer. And brut even though placebo effects do occur if you noticed a small gain on creatine I would suggest (through it’s proven effect in research studies and real life situations) that it was the creatine.