Wellbutrin dosage, forms, and strengths

Wellbutrin is a brand-name prescription antidepressant, also known by its generic name, bupropion. Wellbutrin is used to treat major depressive disorder (depression), as well as other conditions. This medicine works by increasing levels of neurotransmitters (chemical messengers) in the brain called norepinephrine and dopamine. There are various formulations of Wellbutrin, including an immediate-release form, a sustained-release form, and an extended-release form. The dosage and FDA-approved uses vary slightly by formulation. 

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Wellbutrin forms and strengths

Brand-name immediate-release Wellbutrin is no longer available, although a generic version is available. Bupropion might also be sold under other brand names including Forfivo XL, Aplenzin (bupropion hydrobromide), and Zyban, which is indicated for smoking cessation. Zyban has been discontinued in the brand-name form, but is still available as generic.

Wellbutrin SR (sustained-release) and Wellbutrin XL (extended-release) are both available in brand and generic forms. Wellbutrin SR is available as a tablet in three strengths. Wellbutrin XL comes in two dose strengths.

• Immediate-release tablets: 75 mg, 100 mg

• Sustained-release tablets (SR): 100 mg, 150 mg, 200 mg

• Extended-release tablets (XL): 150 mg, 300 mg

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*off-label use

Wellbutrin dosage for depression

Wellbutrin is an antidepressant commonly prescribed to treat major depressive disorder, a mental health condition that is diagnosed when symptoms of depression, such as sadness, loss of enjoyment, and other symptoms, lasting for two weeks or longer. Wellbutrin raises the levels of norepinephrine and dopamine, which pass nerve signals in the brain. By rebalancing these neurotransmitters, the drug helps people better regulate their moods.

• Standard adult dosage for major depressive disorder: 150 mg Wellbutrin SR taken twice per day (300 mg daily); or 150 or 300 mg Wellbutrin XL taken once per day

• Maximum adult dosage for major depressive disorder: 200 mg Wellbutrin SR taken twice per day (400 mg daily) or 450 mg Wellbutrin XL taken once per day

Wellbutrin dosage for anxiety

Sometimes, healthcare providers prescribe Wellbutrin off-label for anxiety. There is not an established or recommended dose of bupropion for this use, so prescribers typically start with a lower dose and gradually increase the dose as needed. While individual dosages may vary, examples follow below. 

• Example adult dosage for anxiety: 150 mg Wellbutrin SR taken twice per day (300 mg daily); or 150 or 300 mg Wellbutrin XL taken once per day

• Example maximum adult dosage for anxiety: 200 mg Wellbutrin SR taken twice per day (400 mg daily) or 450 mg Wellbutrin XL taken once per day

Wellbutrin dosage for seasonal affective disorder (SAD)

Seasonal affective disorder (SAD) is a type of depression that recurs at certain times of the year, usually late fall or winter. It is no longer considered a separate mental health disorder but is now diagnosed as a major depressive disorder with a seasonal pattern. Wellbutrin XL (not Wellbutrin SR) is specifically indicated for this condition.

• Standard adult dosage for major depressive disorder with a seasonal pattern: 150 or 300 mg Wellbutrin XL taken once per day

• Maximum adult dosage for major depressive disorder with a seasonal pattern: 300 mg Wellbutrin XL taken once per day

Wellbutrin dosage for smoking cessation

The active ingredient in Wellbutrin, bupropion, is FDA-approved to help people quit smoking. About one in five people taking bupropion for smoking cessation successfully break their smoking habit. Bupropion’s mechanism is not completely understood for smoking cessation. It is thought to weaken cravings by increasing dopamine in the brain, just as nicotine does. In addition, bupropion weakens the effects of nicotine, making smoking less pleasurable. 

Smoking cessation treatment typically lasts seven to 12 weeks. The patient begins taking bupropion one or two weeks before a target quit date.

• Standard adult dosage for smoking cessation: 150 mg bupropion SR taken twice per day (300 mg daily) 

• Maximum adult dosage for smoking cessation: 300 mg per day

Wellbutrin dosage for weight loss

Wellbutrin is not FDA-approved for weight loss, but healthcare professionals may prescribe it off-label for this use, particularly if a patient is also experiencing depression or anxiety. Because Wellbutrin is not FDA-approved for weight loss, there is no established dosage, so prescribers typically start patients on a lower dose, slowly increasing as needed. Individual dosages will vary; however, some examples follow below. 

• Example adult dosage for weight loss: 150 mg Wellbutrin SR taken twice per day (300 mg daily); or 150 or 300 mg Wellbutrin XL taken once per day

• Example maximum adult dosage for weight loss: 200 mg Wellbutrin SR taken twice per day (400 mg daily) or 450 mg Wellbutrin XL taken once per day

Note that Contrave is an FDA-approved drug that combines two drugs into one pill—bupropion, which is the active ingredient in Wellbutrin, along with naltrexone. Contrave is FDA-approved for weight loss. 

Wellbutrin dosage for children

The U.S. Food and Drug Administration (FDA) has not approved Wellbutrin or bupropion for use in children or adolescents. However, healthcare providers may prescribe Wellbutrin off-label in children or adolescents for depression, attention-deficit hyperactivity disorder (ADHD), or smoking cessation. The dosage varies by age, use, and formulation of bupropion used.

Wellbutrin dosage restrictions

Before taking Wellbutrin, talk to your doctor about your symptoms, medical conditions, and medical history. Also, tell your doctor about all the medications you take, including prescription and over-the-counter drugs, as well as vitamins or supplements. 

Wellbutrin may cause problems in people with certain pre-existing medical or physical conditions. Contraindications are conditions that make taking Wellbutrin too hazardous. Any history of allergic reactions to bupropion is a contraindication. Also, because of the increased risk of seizures, Wellbutrin is never given to people with a seizure disorder, a prior diagnosis of an eating disorder such as anorexia or bulimia, or anyone undergoing abrupt withdrawal from alcohol, barbiturates, benzodiazepines, or anticonvulsants. 

Wellbutrin should not be given within 14 days of drugs in the category known as monoamine oxidase inhibitors (MAOIs), such as methylene blue or linezolid. Wellbutrin has other drug interactions as well. Examples of other drugs that may interact with Wellbutrin include clopidogrel, phenobarbital, metoprolol, ritonavir, carbamazepine, amantadine, antipsychotics, and others. Your healthcare provider will review your medication list for potential drug interactions. 

Bupropion is broken down by the liver and then mostly excreted in the urine. Lower doses may be required for people with kidney problems (renal impairment) or liver problems (hepatic impairment).

• Renally impaired patients—Possible dose or dosing frequency decrease

• Hepatically impaired patients—People with mild liver disease or liver problems may need a lower dose or less frequent dosing of Wellbutrin, and people with moderate to severe liver problems are typically prescribed lower daily doses.

How to take Wellbutrin

Depending on the dose and dosage form prescribed, Wellbutrin is typically taken by mouth once or twice a day with or without food.

• Take this medicine as directed.

• Read all medication guides and instructions that come with this medicine. 

• If you are taking an SR or XL form, swallow the tablet whole. Do not crush, break, cut, or chew it. If you do, the medicine will be released into the body more quickly, raising the risk of adverse effects. If you are not sure which form you are taking, ask your pharmacist.

• Take Wellbutrin SR doses at least eight hours apart.

• Take Wellbutrin XL in the morning. Doses should be spaced at least 24 hours apart.

• It may take several weeks before this medicine begins to show significant results. Give the medicine time to work. 

• Store the medicine in a closed container at room temperature (68°F to 77°F) protected from heat, light, and moisture. Keep out of the reach of children and pets.

Wellbutrin dosage FAQs

Wellbutrin SR vs. Wellbutrin XL: What’s the difference in doses? 

Brand-name Wellbutrin is available in two formulations: Wellbutrin SR (sustained-release) and Wellbutrin XL (extended-release). In addition, generic bupropion is available in an immediate-release formulation (bupropion IR), sustained-release formulation (bupropion SR), and extended-release formulation (bupropion XL). 

After a gradual dose increase, immediate-release bupropion is generally taken in three daily doses spaced at least six hours apart. Wellbutrin SR is usually taken in two daily doses spaced at least eight hours apart, and Wellbutrin XL is taken in the morning as a single daily dose. All formulations of Wellbutrin are increased gradually to lower the risk of seizures and minimize side effects.

How long does it take Wellbutrin to work?

Many people begin noticing effects in the second week. However, it may take several weeks, or even a few months, to experience the full benefit of this medicine. Ask your healthcare provider if you have any questions or concerns about your dose. 

How long does Wellbutrin stay in your system?

Bupropion has a half-life of about 21 hours, which means it takes your body about one day to clear half of a dose, if you do not take any more doses. Also, bupropion breaks down into substances called metabolites, which stay in your body much longer. The end result is that it can take about five to seven days to clear this medicine from your body. 

What happens if I miss a dose of Wellbutrin?

Skip the missed dose and take the next dose at your regularly scheduled time. Don’t double up. Taking too much of this medicine can increase the risk of seizures. 

How long can you take Wellbutrin?

Wellbutrin is often used for months or even many years for depression. For smoking cessation, treatment typically lasts 7-12 weeks.

How do I stop taking Wellbutrin?

Talk to your provider before stopping. Tapering is typically recommended to avoid withdrawal. Your healthcare provider will give you a specific schedule to follow so you can slowly and safely stop taking Wellbutrin. 

What is the maximum dosage for Wellbutrin?

The maximum daily dose of Wellbutrin SR should not exceed 400 mg for depression, or 300 mg for smoking cessation. The maximum daily dose of Wellbutrin XL is 450 mg per day for depression or 300 mg per day for depression with a seasonal pattern.

Is it safe to take Wellbutrin during pregnancy?

Let your provider know if you are pregnant, planning to become pregnant, or breastfeeding. Your healthcare provider will consider the benefits and risks and give you medical advice on the best treatment during this time. 

Can Wellbutrin increase the risk of suicidal thoughts and behavior?

All antidepressants carry a black box warning for increased suicide risk, especially in children, teenagers, and young adults. Monitor symptoms closely and report any changes or worsening in mood or behavior to your healthcare provider right away. If you are experiencing suicidal thoughts or behavior or are in any other type of urgent mental health situation, call or text 988 for the Suicide & Crisis Lifeline or call 911. 

Sources:

• Bupropion, StatPearls (2024)

• Bupropion compound summary, U.S. National Library of Medicine (2025)

• Bupropion prescribing information, U.S. National Library of Medicine (2023)

• Major depressive disorder with a seasonal pattern, National Alliance on Mental Illness (2017)

• Wellbutrin SR prescribing information, U.S. National Library of Medicine (2024)

• Wellbutrin XL prescribing information, U.S. National Library of Medicine (2024)