Lorazepam typically starts to work within 20 to 30 minutes after taking it orally, with the full sedating effects lasting around 6 to 8 hours
. Some sources note the effects may last between 4 to 6 hours, but 6 to 8 hours is the common duration cited
. The drug's half-life-the time it takes for half the dose to be metabolized- is about 10 to 20 hours, averaging around 12 hours. Because it generally takes about five half-lives for a drug to be eliminated, lorazepam can stay in the body for approximately 60 hours (2.5 days) after a single dose
. However, some metabolites of lorazepam can be detectable in urine for up to 6 days or longer, and in hair samples for 30 days or more
. In summary:
- Onset of action: 20–30 minutes after oral intake
- Duration of effects: About 6 to 8 hours (may vary slightly)
- Half-life: Approximately 12 hours (range 10–20 hours)
- Time to clear from system: Around 2 to 3 days for most of the drug, but metabolites may be detectable up to a week or longer
These durations can vary based on individual factors such as age, liver function, dosage, frequency of use, and interactions with other medications
. Avoid driving or operating machinery while feeling drowsy from lorazepam, and do not combine it with alcohol due to increased sedation and risk of breathing problems
