How Long Does Buspirone (BuSpar) Stay in Your System?

How Long Does Buspirone (BuSpar) Stay in Your System

Buspirone is the generic name for an anti-anxiety medication known as Buspar. This medication is considered an anxiolytic medication, meaning it causes your body to release a chemical known as gamma-aminobutyric acid (GABA), which helps reduce anxiety.[1]

While buspirone is incredibly effective in managing anxiety conditions, it can be addictive when abused. If someone were to take large amounts of Buspar at once, they could experience a euphoric high.

If you or a loved one abuse buspirone, you might be wondering how long it stays in your system. This could also help you determine when you will experience withdrawal symptoms upon stopping the use of Buspar. Typically, buspirone will be flushed from your system within 15 hours, as it has a short half-life.

If you are stopping the use of buspirone after taking it daily, you should taper the medication with the help of your doctor, as you could experience symptoms of withdrawal.

Does Buspirone Work Immediately?

When you start taking a new medication to treat your anxiety, you will probably be interested in knowing when it will start working. Buspirone can be incredibly helpful in treating the symptoms of anxiety conditions and often begins working faster than other types of long-term medications.

While buspirone does not relieve symptoms of anxiety immediately, you should begin to notice the effects within 3 to 4 weeks. To experience the benefits of Buspar, you have to be taking the medication daily for at least 14 days in a row.

The side effects of buspirone include:[1]

  • Dizziness and lightheadedness
  • Nausea
  • Diarrhea
  • Headaches
  • Excitement or confusion
  • Fatigue
  • Nervousness
  • Trouble sleeping
  • Weakness or numbness
  • Excessive sweating

These side effects should go away once your body adjusts to the medication. If any of your side effects become difficult to cope with or linger longer than a couple of weeks, contact your doctor for advice.

How Long Does Buspirone Stay in Your System?

A drug’s half-life displays how long it takes your system to eliminate half of the substance. Typically, it takes 4 to 5 half-lives for a medication to be completely rid of your system. Because the half-life of buspirone is between 2 to 3 hours, it should be out of our system 15 hours after your last dose.[2]

While buspirone might leave your system after 15 hours, it can leave behind metabolites in different areas of your body. Even though standard drug panels do not look for buspirone in your system, specialized panels can detect it by looking for those metabolites. Each type of drug test can detect Buspar for varying amounts of time.


Urine tests are the most commonly used drug tests as they are minimally invasive and relatively cheap to conduct. Because of buspirone’s short half-life, they can only detect it for up to 24 to 36 hours after your last dose.


Saliva drug tests look for metabolites of Buspar left behind in the saliva found around your mouth. These tests are not commonly used because they provide a shorter window of detection than urine tests. Saliva tests can detect buspirone for up to 24 hours after you last used it.


Blood tests are not used as often as urine tests because they are invasive and provide a shorter window of detection. However, hospitals may use them to determine if a substance is contributing to your symptoms.

Typically, blood tests can only detect buspirone for 18 to 24 hours after your last dose.


Hair tests can detect any substance in your system (including Buspar) for up to 90 days after your last dose. While these are the most reliable drug tests, they are not commonly used because they can be expensive to analyze in a lab.

Factors that Affect How Long Buspirone Stays in Your System

Several factors can influence how long buspirone stays in your system, including:

  • Metabolism – Individual metabolic rates can affect how quickly your body processes and eliminates buspirone. People with faster metabolisms tend to clear medications from the system more rapidly.
  • Dosage and frequency of use – Higher doses or more frequent usage of buspirone may result in a longer presence in the system as it takes longer for the body to metabolize larger amounts.
  • Duration of use – If someone has been taking buspirone for an extended period, it might accumulate in the body, which can prolong its presence in the system.
  • Liver function – Since the liver plays a crucial role in metabolizing drugs, any liver issues or impairment might affect how long buspirone stays in the system.
  • Age – Generally, younger individuals tend to process medications more efficiently than older adults, which might affect how long buspirone remains in the body.
  • Body Mass Index (BMI) – Individuals with higher BMI might metabolize drugs differently than those with lower BMI, potentially affecting the duration of drug presence in the body.
  • Using other medications or substances – Concurrent use of other medications or substances can influence the metabolism and elimination of buspirone. Some drugs or substances may interfere with its clearance, prolonging its effects.
  • Overall health – Certain health conditions, such as kidney disease or issues that affect overall health and metabolism, can impact the elimination of buspirone from the body.

Should You Quit Buspirone Cold Turkey?

Whether you are using buspirone as prescribed or abusing it, you should not quit it cold turkey. Suddenly stopping the use of Buspar can result in uncomfortable withdrawal symptoms that can be difficult to cope with.

The withdrawal symptoms associated with buspirone include:[2]

  • Irritability
  • Anxiety
  • Agitation
  • Insomnia
  • Tremors
  • Abdominal cramps
  • Muscle cramps
  • Nausea and vomiting
  • Excessive sweating
  • Flu-like symptoms without fever

If you are taking buspirone under the direction of a medical professional, you should contact your doctor before quitting its use. They can help you taper off the medication to avoid withdrawal symptoms.

On the other hand, people who are abusing Buspar should consider attending a drug rehab program to receive professional treatment for their withdrawal symptoms. These programs can provide you with medications that lessen your symptoms and make it easier to focus on recovering from addiction.

Find Help for Buspirone Abuse and Addiction

If you or a loved one are addicted to buspirone, Moving Mountains Recovery Center is here to help. We can provide evidence-based behavioral therapy and teach you a variety of relapse prevention skills to ensure that you achieve long-term recovery from substance abuse.

To learn more about our addiction treatment programs, contact us today.


  1. Medline Plus: Buspirone, Retrieved December 2023 From
  2. The Food and Drug Administration (FDA): Buspar Label, Retrieved December 2023 From
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