How Long is the Ativan Half-Life? Breaking Down The Timeline

Last Medical Review On: May 20, 2024
Updated On: May 20, 2024
4 min read
Written by:

Amanda Stevens, B.S.

Medical Review by:

Dr. Po-Chang Hsu, M.D., M.S.

Ativan Half-Life
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    What you will learn

    • Ativan is prescribed to calm the central nervous system.
    • It treats anxiety, insomnia, seizures, alcohol withdrawal, and sedation.
    • It can be administered orally, sublingually, through injections, or nasal sprays.
    • Ativan’s positive effects include anxiety reduction and muscle relaxation.
    • Side effects include drowsiness, dizziness, confusion, and respiratory depression.
    • The half-life of Ativan (lorazepam) is generally 10 to 20 hours in healthy adults. However, many factors can influence dosing and duration.

    Ativan is one of the brand names for lorazepam. It belongs to a class of medications called benzodiazepines and is one of the most common variants.

    Ativan enhances the effects of a neurotransmitter called gamma-aminobutyric acid (also known as GABA) in the brain, helping to calm the central nervous system.

    What does half-life mean?

    Understanding the half-life of any medicine is important when determining your dosing schedule and managing side effects. A longer half-life means the drug remains in your body for a longer period, which can lead to prolonged effects and potentially increased risk of accumulation. A shorter half-life may require more doses to maintain proper levels in your bloodstream.

    The half-life of Ativan specifically refers to the time it takes for half of the drug to be metabolized and eliminated from your body. Put another way, the half-life is the time it takes for the concentration of the drug in your bloodstream to decrease by 50%.

    Here’s an example. If Ativan has a half-life of 12 hours, after 12 hours, about half the dose you took is still active in your body. Half of the remaining Ativan is eliminated after another 12 hours (or 24 total hours), leaving about 25% of the original dose. This process continues until the drug is cleared from your body.

    It’s important to note that individual factors such as age, liver function, kidney function, and other medications can affect how quickly Ativan is cleared from the body.[1] These things can potentially alter the drug’s half-life.

    What is the half-life of Ativan?

    A healthy adult’s half-life of 1 mg of Ativan is approximately 10 to 20 hours. This means it takes around 10 to 20 hours for half of a dose of Ativan to be eliminated from your body.

    Note that while this is the average half-life of Ativan, individual variations can occur based on the factors listed above. The effects of Ativan may also be felt for a shorter or longer duration than its half-life due to factors including the drug’s potency and active metabolites.

    What is Ativan used for?

    Ativan Uses

    Ativan must be prescribed by a doctor. It should be used with caution and under the supervision of a healthcare professional due to its potential for dependence.[2] Ativan is prescribed for several uses, including:[3]

    • Anxiety: Ativan is prescribed to manage symptoms of anxiety disorders, including generalized anxiety disorder, panic disorder, and social anxiety disorder.
    • Short-term anxiety relief: It can also be used for the short-term relief of symptoms of anxiety. Such symptoms include excessive worry, restlessness, tension, and exhaustion.
    • Insomnia: Ativan may also help induce sleep, especially if anxiety prevents you from sleeping well.
    • Seizures: Ativan can be used as a treatment to control seizures. It helps when other medications are ineffective or contraindicated.
    • Alcohol withdrawal: Ativan can be administered to manage and control symptoms of alcohol withdrawal.
    • Sedation for medical procedures: Ativan is occasionally used to induce sedation and reduce anxiety before surgeries.

    How is Ativan administered?

    Ativan may be administered in several different ways depending on the specific medical condition being treated and the preference of the healthcare provider:

    • Oral tablets: Ativan is most commonly available in tablet form for oral administration.
    • Sublingual tablets: Some variations of Ativan are designed to be placed under the tongue, where they are absorbed directly into the bloodstream. This route of administration can lead to a faster effect than oral tablets.
    • Injection: Ativan can also be administered by injection, depending on the urgency of the need for the medication.

    What are the intended effects of Ativan?

    Ativan, like other benzodiazepine drugs, may produce positive, intended effects and is usually prescribed to treat the following:

    • Alleviating nausea and agitation (off-label): This is beneficial for temporarily treating some unavoidable phobias like flying.[4]
    • Sedation: Ativan has sedative properties that can help induce relaxation and calmness. This makes it useful for managing episodes of anxiety or for promoting sleep in people with insomnia.
    • Anxiety reduction: Ativan is effective at reducing anxiety symptoms.[5] It can provide much-needed relief for those with anxiety disorders.
    • Muscle relaxation: Ativan can help relax your muscles. This is beneficial for conditions associated with muscle tension and muscle spasms.
    • Anticonvulsant: Its anticonvulsant properties mean it can help prevent or reduce the severity of seizures, making it useful in treating epilepsy.
    • Amnesic effects: Ativan can induce temporary memory impairment. This is often beneficial for surgeries.

    What are the potential side effects of Ativan?

    It’s possible that Ativan can cause several different side effects even when used properly. These side effects can vary in severity depending on dosage and your health.

    • Drowsiness: Ativan can cause drowsiness, impairing your ability to drive or operate machinery safely.
    • Dizziness: You may also experience dizziness or lightheadedness while taking Ativan.
    • Weakness: Ativan may cause weakness or fatigue. This is more likely to occur at higher doses.
    • Confusion: Ativan can sometimes lead to confusion or disorientation, especially in older adults or at higher doses.
    • Headache: Headaches are another possible side effect of Ativan use.
    • Blurred vision: Ativan may cause you to experience temporary blurred vision or difficulty focusing.
    • Nausea: You may also experience nausea or vomiting as a side effect of Ativan.
    • Dry mouth: Ativan can dry your mouth out. This is commonly referred to as cotton mouth.
    • Constipation: Constipation may occur with continued Ativan usage.
    • Respiratory depression: In rare instances, Ativan can cause respiratory depression. This is more likely to occur when it’s taken in high doses or in combination with other central nervous system depressants like opioids.

    In a sample of about 3500 patients treated for anxiety, the most frequent adverse reaction to Ativan was sedation (15.9%), followed by dizziness (6.9%), weakness (4.2%), and unsteadiness (3.4%).[6]

    When It’s Time To Seek Help

    Ativan is a controlled substance. If you or a loved one is struggling with Ativan addiction, there are plenty of treatment options available for you. Many treatment centers have programs where you can stay overnight (inpatient) or visit during the day (outpatient) to get better. These places can make a difference and help you get your life back on track.

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    Frequently asked questions about Ativan


    Can you experience Ativan withdrawal?


    Yes, withdrawal symptoms can occur if you stop taking Ativan suddenly after using it regularly for a period of time.[7] Ativan withdrawal symptoms can range from mild to severe and may include increased anxiety or panic attacks, insomnia, agitation, tremors, sweating, rapid heart rate, and hallucinations. It’s recommended to gradually taper off Ativan under the supervision of a healthcare professional to minimize the risk of withdrawal symptoms. If you’re experiencing Ativan withdrawal symptoms, be sure to seek medical help for proper management and support.


    Is Ativan safe for long-term use?


    Choosing to use Ativan for longer periods of time should be made in consultation with your healthcare provider. Your PCP can consider your specific medical needs, treatment goals, and risk factors. If long-term use is necessary, it’s important to use the lowest effective dose for the shortest duration possible to minimize the risks associated with Ativan use.


    Does Ativan interact with other medications?


    Ativan may interact with other medications. It’s important to be aware of these potential interactions for safety reasons. Some medications that may interact with Ativan include:

    • Other central nervous system depressants: Combining Ativan with other drugs that have sedative effects, such as alcohol, opioids, other benzodiazepines, antipsychotics, or muscle relaxants, can increase the risk of excessive sedation, respiratory depression, coma, or death.
    • Antidepressants: Some antidepressants, including selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors, may increase the sedative effects of Ativan.
    • Anticonvulsants: Ativan can interact with anticonvulsant medications, potentially increasing the risk of side effects or altering the effectiveness of either medication.

    Research, C. for D. E. and. (2019). As You Age: You and Your Medicines. FDA.


    Ativan (lorazepam): Side effects, dosage, uses, and more. (2022, November 28).


    Lorazepam: MedlinePlus Drug Information. (2023, February 15).


    Ativan (lorazepam): Side effects, dosage, uses, and more. (2022, November 28).


    Lorazepam: MedlinePlus Drug Information. (2023, February 15).




    PETURSSON, H. (1994). The benzodiazepine withdrawal syndrome. Addiction, 89(11), 1455–1459.

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