When taking herbs, they need to be respected. If you're taking tinctures/extracts they act as other forms of medicine and are potent. Drinking teas, however, are effective but less concentrated. Taking too much Wormwood can be a problem taken in high doses.
Herbs are medicines. Just because you're taking herbs doesn't mean they are less effective or that they can't harm you. People have died from taking herbs because they didn't know what they were doing. Unless you are experienced with taking herbs, stick with the recommended dosages suggested by the manufacturer.