My son is on Ritalin and Tenex. The Tenex doesn't make his sleepy just calmer and more even. The Ritalin helps with the hyperness/impulsivness but it made him moody. The Tenex helped that. Tenex isn't like a stimulant so it isn't fast acting. It takes a little while to build up in the system before you really get the full effect. He takes it three times a day and the last dose is right when he's laying down for bed. That helps the morings. It is still in his system working until his a.m. dose of Ritalin kicks in. The mornings have been a lot smoother since then!
You usually have to go to a specialist (like a psychiatrist) to get Tenex. The pediatricians usually won't prescribe it because it's an "off label" use. It's really a blood pressure medicine for adults. Good luck!
The Tenex made my son sleepy the first day or two until his body got used to it. Now he takes it in the morning and at bedtime with no problem.... the morning dose seems to make his day much more even,. and the bedtime dose helps him go to bed without trouble and wake up much happier.