To do this it must pass through the stomach, enter the bloodstream, and be taken up by the muscle cell. High stomach acid levels are probably the reason. It s even less stable in your stomach. The acid destroys creatine by converting it into creatinine, its waste product that does you no good. So, once creatine reaches the stomach, the amount that is absorbed into the blood may be a lot or a little depending on the amount of stomach acid.
Some people naturally have more stomach acid.
The foods you eat and your level of stress can dramatically increase your amount of acid. Then, we added glucose, which enters the blood stream faster than any other carbohydrate. Insulin drives creatine from the blood into the muscle. In order to get insulin levels up you must eat some a carbohydrate. However, this stimulates stomach acid and destroys the creatine.