Silenor (Doxepin) – Oral

What Is Silenor?

Silenor (doxepin) is a prescription-only oral medication used for people with insomnia who have trouble staying asleep at night.

How Silenor helps with sleep is unclear, but it is thought to block histamine 1 (H1) receptors. Histamine is a small molecule found throughout the body. It signals to the brain for you to stay awake. By blocking histamine receptors in the brain, Silenor causes you to feel drowsy.

Silenor belongs to a class of medications known as tricyclic antidepressants, which are medications named for their chemical structure. They have many uses, such as for depression and anxiety. Due to how this medication works, it should be taken 30 minutes before you go to sleep to make sure you get the most benefit.

Silenor is available in tablet form to be taken by mouth.

Drug Facts

Generic Name: Doxepin

Brand Name(s): Silenor

Drug Availability: Prescription

Administration Route: Oral

Therapeutic Classification: Tricyclic antidepressant

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Doxepin hydrochloride

Dosage Form(s): Tablet

What Is Silenor Used For?

The Food and Drug Administration (FDA) approved Silenor to treat insomnia that is characterized by difficulty staying asleep.

How to Take Silenor

Always follow the directions given to you by your healthcare provider on how to take Silenor.

Generally, you will take Silenor on an empty stomach about 30 minutes before you go to sleep. Do not take this medication if you have had a meal within the last three hours, as it may delay the effects of the medication. Food slows the time required for this medication to reach its maximum level in the body, which may cause you to feel sleepy or drowsy in the morning.


Store Silenor in a cool, dry place. It can be stored between 59 and 86 degrees F. However, do not keep it anywhere it may be exposed to extremely hot or cold temperatures, like in your car or refrigerator. These environments can impact how well your medication works.

Do not freeze this medication. Keep it out of the reach of children and pets to prevent accidental consumption.

How Long Does Silenor Take to Work?

You should experience benefits from the medication on the night you start taking it. It takes about 3.5 hours for the medication to reach its maximum level in the body.

Let your healthcare provider know if your sleep doesn't improve after seven to 10 days of taking it.

This may mean there is another issue that could be causing your sleep problems.

What Are the Side Effects of Silenor?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at or 800-FDA-1088.

Common Side Effects

Common side effects that may occur while you are taking Silenor include the following:

Severe Side Effects

Notify your healthcare provider immediately if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Abnormal thinking and behavior changes
  • Suicidal thoughts
  • Worsening of depression

Call your healthcare provider immediately if you're experiencing depression or have any thoughts of suicide.

Silenor may also reduce fertility. It is unknown if the effects are reversible. Talk to your healthcare provider if this is a concern for you.

Help Is Available

If you or someone you know are having suicidal thoughts, dial 988 to contact the 988 Suicide & Crisis Lifeline and connect with a trained counselor.

For more mental health resources, see our National Helpline Database.

Long-Term Side Effects

Silenor does not have any documented side effects that have occurred after it has been stopped.

Report Side Effects

Silenor may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Silenor Should I Take?

Drug Content Provided by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (capsules or solution):
    • For depression or anxiety:
      • Adults and children 12 years of age and older—At first, 75 milligrams (mg) once a day or in divided doses during the day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 150 mg per day.
      • Children younger than 12 years of age—Use is not recommended.
  • For oral dosage form (tablets):
    • For insomnia:
      • Adults—6 milligrams (mg) once a day.
      • Older adults—At first, 3 mg once a day. Your doctor may adjust your dose as needed.
      • Children—Use and dose must be determined by your doctor.


Consider the following before starting treatment with Silenor. Talk to your healthcare provider about how these factors may affect your medication.


You should not take this medication if you are pregnant or planning to become pregnant. Studies have shown taking Silenor during the third trimester may increase the risk of a condition known as poor neonatal adaptation syndrome (PNAS).

Symptoms of PNAS may include the newborn feeling jittery/irritable or having difficulty maintaining body temperature, decreased muscle tone, and breathing problems.

Talk to your healthcare provider if you are pregnant or planning to become pregnant before starting Silenor. 


Silenor is known to pass through breast milk. It is not recommended to take Silenor if you are nursing due to the potential side effects it may cause in the baby (e.g., excess sleepiness and slowed breathing).


The safety and effectiveness of Silenor in children have not been studied.

Adults Age 65 and Older

People 65 years or older may need to start on a low dosage of Silenor. Studies have shown similar safety and effectiveness in older adults compared to younger adults. However, the possibility of increased sensitivity in people of advanced age should not be ruled out completely. Medications that help promote sleep may cause increased confusion and sleepiness. 

Liver Damage

If you have liver damage, Silenor may have trouble breaking down in the body, leading to higher levels of the drug. It is recommended to start on a low dose if you have liver problems. Talk to your healthcare provider for more information about your treatment plan.

Kidney Damage

There are currently no studies of Silenor in those who have kidney damage. Since only a small amount of Silenor is removed through the kidneys, it is not expected that you will have higher concentrations of Silenor in the body if you have kidney damage.

Missed Dose

It is best to take this medication 30 minutes before you go to bed. Otherwise, if you miss your dose before bedtime, you can take it if you are having trouble falling asleep during the night. Skip the missed dose if you need to be awake soon, as Silenor can increase your drowsiness.

Overdose: What Happens If I Take Too Much Silenor?

The active ingredient, doxepin, is occasionally used at 10 to 50 times the dose of Silenor for other conditions.

Taking excessive amounts of Silenor (higher than 6 milligrams) may cause:

  • Low blood pressure
  • Constipation
  • Indigestion
  • Urinary retention
  • Disorientation or hallucinations
  • Numbness and tingling sensation
  • Movement disorders, such as tremors, restlessness, and uncontrolled movements
  • Seizures

These can be life-threatening issues and require hospitalization for proper management.  

What Happens If I Overdose on Silenor?

If you think you or someone else may have overdosed on Silenor, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Silenor, call 911 immediately.


Drug Content Provided by IBM Micromedex®

It is very important that your doctor check the progress of you or your child at regular visits to allow for changes in the dose and to check for any unwanted effects.

For some children, teenagers, and young adults, this medicine can increase thoughts of suicide. Tell your doctor or your child's doctor right away if you or your child start to feel more depressed and have thoughts about hurting yourself. Report any unusual thoughts or behaviors that trouble you or your child, especially if they are new or are getting worse quickly. Make sure the doctor knows if you or your child have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. Also tell the doctor if you or your child have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. Let the doctor know if you or anyone in your family has bipolar disorder (manic-depressive illness) or has tried to commit suicide.

Do not take doxepin if you have taken a monoamine oxidase (MAO) inhibitor (eg, isocarboxazid [Marplan®], phenelzine [Nardil®], selegiline [Eldepryl®], or tranylcypromine [Parnate®]) in the past 2 weeks. If you do, you may have confusion, agitation, restlessness, stomach or intestinal symptoms, a sudden high body temperature, an extremely high blood pressure, or severe convulsions.

If you or your child are using this medicine for depression or anxiety, do not stop taking it without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help prevent a possible worsening of your condition and reduce the possibility of withdrawal symptoms, such as headache, nausea, or a general feeling of discomfort or illness.

Silenor® tablets may cause sleep-related behaviors such as driving a car (sleep-driving), walking (sleep-walking), having sex, making phone calls, or preparing and eating food while asleep or not fully awake. If any of these reactions occur, tell your doctor right away.

If you think you need to take Silenor® tablets for 7 to 10 days, talk to your doctor.

This medicine may cause some people to become drowsy. Make sure you know how you react to this medicine before you drive, use medicines, or do anything else that could be dangerous if you are drowsy or not alert.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, allergies, or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. This effect may last for a few days after you stop taking this medicine. Check with your doctor before taking any of the above while you or your child are using this medicine.

Tell your doctor if you are pregnant or planning to become pregnant during treatment with this medicine. This medicine may cause symptoms of sedation (eg, breathing problems, sluggishness, low muscle tone, feeding problems, or withdrawal symptoms) in the baby during the third trimester.

Talk with your doctor before using this medicine if you plan to have children. Some men and women who use this medicine have become infertile (unable to have children).

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines) and herbal or vitamin supplements.

What Are Reasons I Shouldn’t Take Silenor?

Do not take Silenor:

  • If you are allergic to its active ingredient, doxepin, or if you are allergic to any of its inactive ingredients
  • If you are taking a medication class known as monoamine oxidase inhibitors (MAOIs) or have used an MAOI in the past two weeks. Using both medications together can cause dangerously high blood pressure. Examples of MAOIs include Zelapar (selegiline), phenelzine, and isocarboxazid
  • If you have untreated narrow angle glaucoma or if you have severe urinary retention

What Other Medications Interact With Silenor?

Silenor is broken down in the body by an enzyme in the liver known as CYP450. Medications that block this enzyme may cause increased concentrations of Silenor in the body, which can enhance its side effects. Some examples of CYP450 inhibitors are:

Tagamet (cimetidine), a medication used to treat stomach ulcers, is also broken down by CYP450. The use of cimetidine and Silenor together has been shown to double the concentration of Silenor in the body. If you must use these two drugs together, your healthcare provider may adjust your dosage.

Additionally, taking Silenor with the following may enhance its sedative effects:

This is not a complete list of potential drug interactions. Before starting treatment, tell your healthcare provider about any other medicines you take or plan to take, including over-the-counter (OTC) nonprescription products, vitamins, herbs, supplements, and plant-based medicines.

What Medications Are Similar?

Silenor belongs to a broad class of medications known as tricyclic antidepressants. Tricyclic antidepressants are often used to treat symptoms of depression, and not all of them can be used for insomnia. In fact, certain tricyclic antidepressants can cause sleep difficulties as a side effect.

Examples of tricyclic antidepressants include:

Other commonly used medications for sleep disorders include:

This is not a list of drugs recommended to take with Silenor. In fact, you should not take these drugs together. Talk to your pharmacist or a healthcare provider if you have any questions.

Frequently Asked Questions

  • What is Silenor?

    Silenor is a medication that may be used if you have trouble staying asleep.

  • When is the best time to take Silenor?

    Take this medication exactly as directed by your healthcare provider. It is recommended to take your dose about 30 minutes before you go to sleep.

  • Should I keep taking Silenor if it has not helped after seven days?

    Contact your healthcare provider if you have not experienced any improvement in your sleep or if it has worsened within seven to 10 days. If this is the case, there may be another issue contributing to your insomnia.

How Can I Stay Healthy While Taking Silenor?

It's important to take your medication exactly as directed by your healthcare provider. Additionally, maintaining a balanced diet, staying hydrated, and engaging in regular physical activity can help improve your overall health.

There are also healthy sleeping habits to practice. Try the following proper sleep hygiene measures:

  • Avoid screens (e.g., phone, computer, TV) too close to bedtime.
  • Set a consistent sleep schedule that you can stick with.
  • Limit your bed use to sleeping.
  • Avoid consuming caffeine or alcohol in the afternoon or evening.
  • Set up a comfortable sleep environment in your bedroom.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare professional. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content as indicated on the page.

The author would like to recognize and thank Cody Ryan Thomas for contributing to this article.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. DailyMed. Label: Silenor- doxepin hydrochloride tablet.

  2. Scammell, TE. et al. Histamine: neural circuits and new medications. Sleep. 2019;42(1). doi: 10.1093/sleep/zsy183

  3. Schroeck JL, Ford J, Conway EL, et al. Review of safety and efficacy of sleep medicines in older adults. Clin Ther. 2016;38(11):2340-2372. doi:10.106/j.clinthera.2016.09.010

  4. Neubauer DN, Pandi-Perumal SR, Monti JM, et al. Pharmacotherapy of insomnia. Journal of Central Nervous System Disease. 2018. doi: 10.1177/1179573518770672

  5. MedlinePlus. Doxepin (insomnia).

  6. Forsberg L, Navér L, Wide K. Neonatal adaptation in infants prenatally exposed to antidepressants - clinical monitoring using neonatal abstinence score. PLoS One. 2014;9(11):e111327. doi:10.1371/journal.pone.0111327

  7. Nazarian PK, Park SH. Antidepressant management of insomnia disorder in the absence of a mood disorder. Mental Health Clinician. 2014;4(2):41-46.

  8. Neubauer DN. Pharmacotherapy for insomnia in adults. UpToDate.

  9. American Academy of Sleep Medicine. Healthy sleep habits.