Had valium a week ago still showing in a drug test a week later how long does it take to leave my system?

4-6 weeks max: Depending on the test used and how long one has been using it. After brief use, 4-5 days is enough. Valium has a very long half life--up to 200 hours in some older people for its concentration to drop to 1/2; 24 hours in young and healthy. If used on a daily basis for a long time though, it gets stored internally and only slowly released. Hence 4-6 weeks. Best to discuss with an md in person.

Varies: It will take its own time and don't take any more.