Valerian root dosage will vary based on the individual using it. Recommended dosages vary between 300 and 900 mg. When first taking Valerian do so about an hour before you plan to go to bed as it does cause drowsiness. In some individuals Valerian root can take up to a month to build up in high enough levels in the body to have any effect at all and some will feel the effects the first time they take it.
As with any herbal supplement start with a low dose and gauge how your body reacts. Valerian can have harmful side effects so make sure to discontinue use if anything feels wrong.