How long does 100 mg of orally ingested Valium take to leave your system?

Valium (diazepam) has a half-life of about 20 to 50 hours, depending on individual factors such as metabolism, age, and liver function. Generally, it can take several days for 100 mg of Valium to be eliminated from the system completely. However, its effects may diminish within a few hours after ingestion. For complete clearance, it may take up to a week or more.