Aspartame is rapidly hydrolyzed in the small intestines. Even with ingestion of very high doses of aspartame (over 200 mg/kg), no aspartame is found in the blood due to the rapid breakdown. Upon ingestion, aspartame breaks down into residual components, including aspartic acid, phenylalanine, methanol, and further breakdown products including formaldehyde and formic acid. Human studies show that formic acid is excreted faster than it is formed after ingestion of aspartame. In some fruit juices, "higher" concentrations of methanol can be found than the amount produced from aspartame in beverages.