Valerian is a herb that has been used for centuries as a sleep aid. It is available as an extract or in pill form. However, it is important to note that there are no specific guidelines on how much valerian should be taken per day. Some people take up to 10 grams per day while others only take a few capsules. A person must consult a doctor before using valerian if they are already taking: benzodiazepines, such as Xanax, Valium, or Ativan central nervous system depressants, such as phenobarbital or morphine other sleep-aiding dietary supplements, such as kava or melatonin The sedative and depressant properties of these drugs and supplements might combine with those of valerian, resulting in grogginess or more severe adverse effects.