One of the most commonly asked questions about creatine is whether it needs to be cycled or not. This question arose when researchers fed rats more creatine than humans could consume and noted a decrease in creatine transporter molecules. This may not be a realistic scenario, as human research with common dosages has shown no effect on creatine transporter.
Some people make it standard practice to cycle supplements every 12 weeks, but I don't cycle creatine. This is because I use the 3g post-workout protocol and thus maintain my elevated creatine levels rather than constantly overloading my body. This means I consume a maximum of 20g of supplemental creatine per week. Some people use this each day! In other words, creatine doesn't need to be cycled unless it's overused.
TESTOSTERONE NATION - The Creatine Controversy