How Long Do Antidepressants Stay in Your System?

People using certain types of medications may wonder, “How long do antidepressants stay in your system?” The answer can vary, depending on the type of antidepressant you’re taking and the drug’s half-life, which is the amount of time it takes for half of the antidepressant to leave the body.

Millions of people use antidepressants to treat depression as well as other conditions including anxiety, phobias, bulimia, or chronic pain.

They improve people’s moods by making neurotransmitters such as serotonin and norepinephrine (also known as noradrenaline or noradrenalin) more active. Neurotransmitters are chemicals that transmit signals within the nervous system.

While many people use antidepressants, many also have questions about them, such as:

  • What are some types of antidepressants?
  • What are the differences among antidepressants?
  • How long do antidepressants last?

There are many answers to these questions.

What Are Some Types of Antidepressants?

In addition, many types of antidepressants produce different effects. They include:

Serotonin and norepinephrine reuptake inhibitors (SNRIs) prevent nerve cells from reabsorbing the serotonin and norepinephrine they’ve released and allow this serotonin and norepinephrine to continue to affect a person’s body and brain. Common types of SNRIs include desvenlafaxine (Pristiq), duloxetine (Cymbalta), and venlafaxine (Effexor XR).

Selective serotonin reuptake inhibitors (SSRIs), which also prevent nerve cells from reabsorbing the serotonin they’ve released, prolong the effects of these neurotransmitters. Fluoxetine, which goes by the brand name Prozac, is a common SSRI medication along with sertraline (Zoloft), escitalopram (Lexapro), and paroxetine (Paxil, Pexeva).

Tricyclics and tricyclic-related antidepressants also affect the reabsorption of serotonin and norepinephrine. They can also affect other bodily chemicals; therefore, they might produce more side effects than other antidepressants. Tricyclic antidepressants include imipramine (Tofranil), doxepin and desipramine (Norpramin), nortriptyline (Pamelor), and amitriptyline.

Monoamine oxidase inhibitors (MAOIs) make it more difficult for the enzyme monoamine oxidase to break down serotonin and norepinephrine. Because of the interactions these drugs can cause, people using these drugs need to monitor their diets and other medications and typically only use MAOIs after they’ve tried other types of antidepressants.

Other medications don’t fit into these common categories but are also prescribed for their antidepressant effects. Bupropion (Wellbutrin) is one such drug.

Different antidepressants affect people differently. So if people find that their medications aren’t producing the intended effects, their doctors might prescribe other types of antidepressants, authorize the use of more than one antidepressant, or combine antidepressants with other types of medications.

How Long Do Antidepressants Stay in Your System?

When searching for antidepressants that are right for them, people might want drugs that affect their bodies for certain lengths of time. They might want to know how long they last.

To determine this, they might want to research the half-life of a medication. A drug’s half-life is the amount of time it takes for half of a drug’s active ingredients to leave the body.

Depending on the drug, the half-life of an antidepressant can vary. The half-life of an antidepressant can be anywhere from one to two hours to as long as multiple days—around six days (144 hours), in fact.

Other factors can also affect a drug’s half-life, including a person’s health, weight, age, and genetics. Typically, half-life refers to how a regular dosage of a drug affects a healthy adult.

How Long Are Antidepressants Detectable in Urine?

If you’re wondering how long do antidepressants stay in your urine, the answer can vary.

It can depend on how much people use. If they use more than the prescribed dose, the effects might last longer. But if people use drugs with shorter half-lives in the prescribed amounts, the drugs probably won’t affect their bodies for long.

For example, when an antidepressant has a half-life of 24 hours, half the drug is gone from the body 24 hours (a day) after a person takes it. So in 48 hours, or two days, there’s a good chance that antidepressant drug tests won’t be able to find evidence of the drug in a person’s urine or by other means.

How Long Do Antidepressants Stay in the System and Affect Treatment?

Because antidepressants are so different from one another, people might wonder how long they stay in the system. They might ask, “Do antidepressants show up in a drug test?”

Again, there are no simple answers to these questions. Antidepressant drug test detection time depends on the drug and when people used it.

A person who uses an antidepressant with a shorter half-life and takes a drug test a few days afterward may have screenings that don’t show any evidence of the drug. But if this same person uses a medication with a longer half-life, it might still be in the body and appear in drug tests.

How Can Knowledge About Antidepressants Assist Treatment?

Antidepressant drugs with shorter half-lives don’t linger in the body for long. As a result, they don’t create lasting effects.

That means people might experience withdrawal effects from them relatively quickly. Doctors can try to prevent this by prescribing antidepressant drugs with longer half-lives that create longer sensations.

Other antidepressants work differently. Antidepressants known as monoamine oxidase inhibitors (MAOIs) produce changes in a person’s brain chemistry that can last for weeks, long after their half-lives.

Doctors and other health care providers can work with people to determine if antidepressants are right for them and to find medications and different treatment approaches that can assist their mental health.


  1. – Antidepressant Use Among Adults: United States, 2015-2018
  2. – How Can I Compare Different Antidepressants?

Medical disclaimer:

Sunshine Behavioral Health strives to help people who are facing substance abuse, addiction, mental health disorders, or a combination of these conditions. It does this by providing compassionate care and evidence-based content that addresses health, treatment, and recovery.

Licensed medical professionals review material we publish on our site. The material is not a substitute for qualified medical diagnoses, treatment, or advice. It should not be used to replace the suggestions of your personal physician or other health care professionals.

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