I have had ADHD my whole life and just recently got on Ritalin but the doc said take one 10mg tablet once a day in the morning to start out. I was amazed as Ritalin does not last that long. I took it once a day and it lasted for about 4-6 hours a dose. Now the doc put me on Methylphenidate (http://www.dogpile.com/info.dogpl/clickit/search?r_aid=600B420115C549049D31601B3FDC3F20&r_eop=1&r_sacop=8&r_spf=0&r_cop=main-title&r_snpp=6&r_spp=2&qqn=BxPjCrq)&r_coid=239138&rawto=http://www.mentalhealth.com/drug/p30-r03.html) E.R. 20mg once a day. How long will this stuff last compared to Ritalin and also do the extended formulas last longer in adults then children since our metabolisms are slower?
Thanks for all the help:)

methylphenidate is Ritalin, ER is the extended release version.

I was on Concerta, a version of Ritalin ER. It only lasted 5-6 hours for me (it's supposed to last 10-12 hours). My Dr. just put me on Ritalin IR (instant release) this week to have more control over spreading out the dosage.

I prefer the ER since you have to take less pills during the day. I think Ritalin IR is supposed to last 3-4 hours, since it lasted longer on you, the ER may last all day.