How long does guanfacine until the full benefit/maximum results are reached? just started 4mg extended release at night

Effect is now: Guanfacine works in your brain by reducing the amount of "sympathomimetic tone"; in other words it slows things down. It is often used for ADHD and for sleep. Unlike some medications, like antidepressants that can take a few weeks to be fully effective, guanfacine should be effective within the first 2-3 uses. Give it time though, as behavior modification is also a part of the therapy.

Guanfacine: I have not prescribed guanfacine but the literature I reviewed indicated that it usually takes a couple of weeks to get a good response & up to 4 to 8 weeks for maximum benefit.