Cycling
Many people choose to cycle creatine, taking it for a number of months, discontinuing its use for several weeks, and then taking it again. Cycling creatine is based on the theory that your body eventually becomes "resistant" to the beneficial effects of supplementation. But there's currently no evidence to show this is necessary.
Animal studies show that large doses of creatine given to animals for three months down regulates (makes less active) the parts of a cell that transport creatine into the muscle.
However, the amounts of creatine (1-2 grams per kilogram of bodyweight daily — the equivalent of 70-140 grams of creatine for someone weighing 70 kilograms) are far higher than those used in most studies. The same doesn't hold true in humans using lower doses.
One trial, led by Dr. Mark Tarnopolsky, shows that four months of creatine supplementation (0.075 grams per kilogram of bodyweight daily — the equivalent of five grams daily for someone weighing 70 kilograms) does not alter creatine transporter protein content.