My friend took 30mg of valium yesterday only once and has a urine test in two weeks, he weighs 125 and is 6ft tall, when will it be out of the urine?

High dose: Your friend has a high tolerance to valium if s/he took that much and was still awake. Valium itself has a half-life of 30-60 hours, but some of its metabolites have half-lives up to 100 hours. This could remain detectable in urine for 5 x 100 hours, or 20-21 days (3 weeks).

UDS: Valium can be detected with a urine drug screen for up to one to six weeks.