*grin* look at my post!!! Read the LABEL -- use the **adult human dose** -- it's gonna depend on what form of the herb, but probably 2 twice or three times a day.
The label will tell you a dose for an adult human - use that. It doesn't go by 'weight' and valerian is more like a tonic anyway (more doesn't make it work 'stronger' -- it makes it work a bit 'longer').