The percentage of those of Hispanic origin in the United States who were of Mexican background in 2013. Another 9.5 percent were of Puerto Rican background, 3.7 percent Cuban, 3.7 percent Salvadoran, 3.3 percent Dominican and 2.4 percent Guatemalan.
Onset of effects occurs within 30-60 minutes after taking Concerta. After that, duration of action lasts from 8-12 hours. And the average times to reach peak plasma concentrations across all doses of Concerta occur between 6-10 hour s. The average half-life for Concerta in adults is about 3.5 hours.
MethylPhenidate - marketed under the brand names Ritalin, Methylin, Concerta and Tranquilyn - can be detected for a shorter time with some tests, but can be visible for up to three months in other tests.