It is only dangerous if you take a silver bullet approach and try to eliminate them too quickly. Doing so can complicate a delicate situation with a radical herxheimer reaction. If you are afraid, start with half the recommended dose and slowly increase from there.
If you take the recommended dose and don't get any results, take twice the recommended dose. Keep increasing until you start feeling your body detox. It can sometimes take a couple of weeks to see results, especially if you are prone to constipation and have a great big belly. It is important to assist your colon in getting rid of them. Do this and you will likely see results sooner.