However, Valium's typical half life in a young, healthy person is about 24 hours. is a relatively low risk for addiction when compared to other drugs (like Vicodin, hey i took 2 valiums that where 5mg i was just wondering how long will they. Jun 21, - The half-life for Valium is 30 to 56 hours. This means it'll take somewhere within that window for half of the drug to be eliminated from your body Missing: hydrocodone. Jun 22, - See how long it stays in the system so you can avoid problems. benzodiazepines (Xanax, Librium, Klonopin, Diastat, Valium, Ativan, Restoril, The half-life of hydrocodone is about 4 hours, which it the time in which half of.