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How long does it take for Ativan to work?

Medically reviewed by Kristianne Hannemann, PharmD. Last updated on July 31, 2025.

Official Answer by Drugs.com

The amount of time it takes for Ativan (lorazepam) to work depends on the formulation you are taking. For the oral tablets and liquid, it starts to work within 30 minutes. The intravenous (IV) formulation takes about 1-3 minutes to work, and the intramuscular version takes 15-30 minutes to start working.

Do not take more Ativan if you feel like it is not working for you. Keep in mind that it can take hours to notice the full effects. Speak to your healthcare provider if you are concerned with how well Ativan is working.

What Can Affect How Quickly Ativan Works?

Ativan onset time (how long it takes for Ativan to work) can vary significantly from person to person. While most people will begin to feel the effects of oral Ativan within 15–30 minutes, several factors influence this timeline:

Tip: Always take Ativan exactly as prescribed. Never take an extra dose if you don't feel effects quickly; consult your healthcare provider if you have concerns about how the medication is working for you.

Related questions

What Does Ativan Feel Like When It Starts Working?

Ativan is known for its calming, quick-acting relief. Most people describe the onset as:

Some users experience initial drowsiness or muscle relaxation and may even fall asleep quickly after taking Ativan, especially if taken for sleep or high anxiety.

How Does Ativan Compare to Xanax for Onset and Duration?

Xanax (alprazolam) has a slightly faster onset but shorter duration, making it ideal for quick but brief relief in panic or acute anxiety. Ativan offers a more gradual onset and a longer duration, often preferred for managing generalized anxiety over several hours.

Medication Onset (oral) Peak Effect Duration
Ativan 15–30min 1–2hrs 6–8hrs
Xanax 30-60min 1–2hrs 4–6hrs

This is not all the information you need to know about Ativan for safe and effective use and does not take the place of your doctor’s directions. Review the full patient medication guide and discuss this information and any questions you have with your doctor or other health care provider.

References
  1. George, T. T., et. al. 2023. Alprazolam. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Accessed on July 31, 2025 at  https://www.ncbi.nlm.nih.gov/books/NBK538165/
  2. Ghiasi, N., et. al. 2024. Lorazepam. In: StatPearls [Internet]. Accessed July 26, 2024 at https://www.ncbi.nlm.nih.gov/books/NBK532890/
  3. Greenblatt, D. J., Allen, M. D., Locniskar, A., Harmatz, J. S., & Shader, R. I. (1979). Lorazepam kinetics in the elderly. Clinical pharmacology and therapeutics, 26(1), 103–113. https://doi.org/10.1002/cpt1979261103
  4. Lorzepam tablet [package insert]. Updated May 2023. Amneal Pharmaceuticals LLC. Accessed on July 31, 2025 at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4fae1607-69d7-47ce-9b78-7474af50036d
  5. National Health Service. Updated February 2023. About lorazepam. Accessed July 26, 2024 at https://www.nhs.uk/medicines/lorazepam/about-lorazepam/

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