Early research (Harris et al., 1992) discovered that ingestion of just 5g of creatine monohydrate 4 - 6 times a day for 2 days demonstrated increases in total creatine concentrations in muscle.  However, these increases were individual responses and further studies have shown that an individual is either a "responder" or "non-responder" to creatine supplementation.

High doses of crearine is not needed to increase and maintain high muscle creatine concentrations.  Unlike most manufacturers suggest, increased levels can occur with much lower doses over longer periods of time.  Research shows that 3g/day for 4 weeks produced the same increase in subjects creatine muscle concentrations as did dosing 20g/day for 5 - 7 days.  After a loading phase of creatine studies suggest that only 2 - 5g/day are needed to maintain increased creatine levels.

Once creatine is ingested it appears in the bloodstream 30 - 60 minutes later and is taken up first by working muscles.  Creatine turnover is relative to an individual's workload, body mass, and body composition which all need to be accounted for when determining proper dosing amounts.  The following chart contains recommended dosing levels based depending on ones body weight.
 
 

Once creatine supplementation is stopped elevated muscle creatine concentrations can take 4 weeks before it returns to pre-supplementation levels.  It is recommended that athletes "wash out) or cycle off of creatine completely during natural breaks in between seasons.  During the first 3 - 4 weeks of training it is advised not to supplement with creatine and force physiological adaptations from the new training demands / loads without the assistance of creatine.  This assures an athlete will continue to remain a responder to creatine and that it doesn't become a training "crutch".