Many creatine packages recommend starting with a loading phase: around twenty grams a day, split into four servings, for five to seven days. After that you switch to a maintenance dose. The question is whether that first week achieves anything.
What a loading phase does
Creatine is stored in your muscles as phosphocreatine. That store is not infinite: at some point your muscles are saturated and taking more serves no purpose. A loading phase gets you to that saturation point faster.
The classic research on this compared two schedules. Twenty grams a day for six days produced a rise of roughly twenty percent in total creatine concentration in the muscle. Three grams a day for twenty-eight days produced the same rise.
In other words: the end point is identical. Only the route there differs in length.
Why you usually do not need it
If the end result is the same, the question becomes practical. Are you in a hurry?
For most people the answer is no. You are not going to set a personal record in week one. Anyone training consistently will barely notice the difference between being saturated after a week or after a month in their progress across a season.
On top of that, a loading phase costs you four times as much product that week. And many people report stomach or bowel complaints at high doses: bloating, cramps or loose stools.
When it can make sense
There are situations where speed does matter. If you have a competition or tournament in two weeks and want to be saturated by then, loading gets you there in time. The same applies if you want to get back to level quickly after a period without creatine.
If you choose to do so, spread the daily amount across four moments rather than taking it all at once. That reduces the chance of stomach and bowel complaints.
The practical choice
Simply start with three to five grams a day and keep it up. After a number of weeks your muscle stores are saturated and stay that way, as long as you keep taking it daily.
Sources
Hultman E. et al. (1996). Muscle creatine loading in men. Journal of Applied Physiology. Research in which twenty grams of creatine a day for six days and three grams a day for twenty-eight days both produced a rise of roughly twenty percent in total muscle creatine.
Saturated sooner, not more saturated
Two routes to the same end point in your muscle.
Over a whole season you barely notice the difference between being saturated after a week or after a month.
The practical choice: start with three to five grams a day and keep it up.
Related reading
Creatine side effects: what is true about the stories?
What is creatine and how does it work?