Does stamina-rx interfere with other drugs such as concerta? I take concerta 34mg for ADD and took it at 7:30 am but I was hoping to take this now

I wouldn't. There are a number of components in Stamina-Rx that may be unsafe, including yohimbe, a stimulant, which has been linked to irregular heart beat and even heart attack. In general, I would not use this supplement which, like all supplements, is not scrutinized for safety by the FDA. I would especially not take it with Concerta, also considered a stimulant.