Wellbutrin SR is a sustained-release form of the antidepressant bupropion. It is FDA-approved to treat major depressive disorder (MDD). Bupropion under a different brand name is also used to help some people quit smoking. Wellbutrin SR is typically taken twice a day.
This guide explains how Wellbutrin SR works, how it differs from other forms of bupropion, and what to expect from dosing, benefits, and side effects.
Key Takeaways
Taken twice daily. Wellbutrin SR (sustained-release bupropion) is typically taken twice a day to treat major depressive disorder (MDD). It works by increasing the activity of two brain chemicals, dopamine and norepinephrine.
Sustained-released formulation sits between immediate-release and extended-release. Bupropion comes in immediate-release (IR), sustained-release (SR), and extended-release (XL) forms. SR releases the medication more slowly than IR but requires more frequent dosing than the once-daily XL.
Follow dosing closely: Taking doses at least 8 hours apart and staying within prescribed single-dose limits helps reduce the risk of seizures. Take Wellbutrin SR tablets whole, exactly as prescribed, and never crush, chew, or split them.
What Is Wellbutrin SR?
Wellbutrin SR is a brand name for one of the formulations of bupropion. The letters ‘SR’ stand for sustained release, which means the tablet releases the medication slowly over several hours instead of all at once. This helps maintain steadier medication levels in the body and allows for twice-daily dosing.
Bupropion belongs to a class of antidepressants called aminoketones. It works by blocking the reuptake of norepinephrine and dopamine, and helps keep more of these chemicals available in the brain.
Unlike selective serotonin reuptake inhibitors (SSRIs), bupropion has little effect on serotonin. If you’re curious how it compares with SSRIs, see our guide on whether Wellbutrin is an SSRI. Wellbutrin SR comes in 100 mg, 150 mg, and 200 mg tablets.
Wellbutrin SR vs. XL vs. IR: What's the Difference?
Bupropion comes in three main forms. They contain the same active drug but release it at different speeds, which changes how often you take them. Here is how each one works.
Wellbutrin IR (Immediate-Release)
The immediate-release form releases bupropion quickly, so it is usually taken 2-3 times a day with doses spaced apart. Because medication levels rise and fall relatively faster, it requires more frequent dosing than SR and XL forms. According to prescribing information, IR is the oldest of the three formulations and is used less often today.
Wellbutrin SR (Sustained-Release)
The sustained release form releases bupropion more slowly than the IR form, so it is usually taken twice a day. Peak levels in the blood are usually reached about 3 hours after a dose. Many people find twice daily dosing easier to manage than three times a day.
Wellbutrin XL (Extended-Release)
The extended release form releases bupropion even more slowly, so it is typically taken just once a day. Many people prefer this formulation because of the convenience of taking one dose a day.
What Is Wellbutrin SR Used For?
Wellbutrin SR is FDA-approved to treat major depressive disorder, often just called depression. A related form of bupropion approved under a different brand name is also used to help people quit smoking. In some cases, healthcare providers may prescribe bupropion off-label for other conditions when they believe it is appropriate.
Major depressive disorder (MDD). The main FDA-approved use is treating depression, including symptoms such as low mood, low energy, and loss of interest in activities.
Seasonal affective disorder (SAD). An extended release form of bupropion is approved to help prevent depressive episodes in people with SAD.
Smoking cessation: A sustained release form of bupropion is also used to help reduce nicotine cravings and withdrawal symptoms, sold under a different brand name.
Some people may prefer bupropion because it is generally less likely to cause weight gain or sexual side effects compared to other antidepressants. You can read more about antidepressants that don’t cause weight gain.
Wellbutrin SR Dosage
Your healthcare provider will help determine the dose that’s right for you based on several factors. The information below gives general prescribing guidelines, and is not a substitute for personalized medical advice. Do not change your dose without talking to your healthcare provider.
For depression, treatment with Wellbutrin SR often starts at 150 mg once daily in the morning.After several days, your provider may increase the dose to 150 mg twice a day, for a total of 300 mg a day. The maximum recommended dose is usually 400 mg a day, given as 200 mg twice a day. To help lower the risk of seizures, single doses are kept at or below 200 mg, and should be spaced at least 8 hours apart.
Starting dose: Often 150 mg once daily in the morning.
Common target: 150 mg twice daily, totaling 300 mg per day.
Maximum: Usually 400 mg per day, as 200 mg twice daily.
Spacing: Doses are kept at least 8 hours apart.
Like other antidepressants, Wellbutrin SR can take several weeks to reach its full effect. However some people may notice increased energy sooner. Learn more in our guide on how long Wellbutrin takes to work and the early signs it is working.
How to Take Wellbutrin SR
A few simple habits can help Wellbutrin SR work well and reduce the risk of side effects.
Swallow the tablets whole. Do not crush, chew, or split them. Breaking a sustained-release tablet can release the medication too quickly and increase the risk of side effects, including seizures.
Take the second dose earlier in the day. Because Wellbutrin SR can be activating, taking it too late may make it harder to fall asleep.
Keep the doses spaced out. Following the prescribed schedule helps reduce the risk of seizures.
Do not double up on doses. If you miss a dose, skip it and take your next dose at the usual time. Do not take two doses close together.
Wellbutrin SR Side Effects
Like all medications, Wellbutrin SR can cause side effects. Most are mild and improve as your body adjusts to the medication. Common side effects include:
Dry mouth
Trouble sleeping
Headache
Nausea
Feeling restless or anxious
Increased sweating
Fast heartbeat (tachycardia)
Seek medical attention right away if you experience a seizure, a severe allergic reaction, or new or worsening suicidal thoughts or behavior. If side effects are bothersome or do not improve, talk with your healthcare provider rather than stopping the medication on your own.
Safety and Who Should Avoid Wellbutrin SR
Wellbutrin SR can increase the risk of seizures, and the risk tends to go up with higher doses. Because of this, it is not appropriate for everyone.
Wellbutrin SR is generally not recommended for:
People with a seizure disorder
People with a current or prior diagnosis of eating disorders such as anorexia or bulimia, as these conditions can increase seizure risk.
People trying to stop alcohol, benzodiazepines, barbiturates, or antiseizure medications, since withdrawal can also increase the risk of seizures.
Your healthcare provider can determine whether Wellbutrin SR is a safe option based on your medical history and any other medications or supplements you take.
Switching Between Wellbutrin SR, XL, and IR
Some people switch between the SR and XL forms of Wellbutrin, often to move from twice daily to once daily dosing or the other way around. Because both contain bupropion, a provider can usually match the total daily dose when switching.
However, these formulations release bupropion at different rates, so they are not interchangeable on their own. This also means that timing and the safe limits of single doses vary. Your provider will use this information and your individual needs to help map out a safe plan and keep single doses within the limits that lower seizure risk.
What to Expect in the First Weeks on Wellbutrin SR
Starting Wellbutrin SR can involve an adjustment period. Knowing what to expect can help you feel more prepared and stay consistent with the treatment long enough to notice benefits.
Early activating effects. Some people notice increased energy, mild jitteriness, or trouble sleeping during the first few weeks. These effects often improve as the body adjusts.
Gradual mood improvement. The lift in mood usually becomes noticeable over the first few weeks rather than appearing overnight.
Pay attention to your sleep. If the second dose makes it difficult to fall asleep, talk with your healthcare provider about whether taking it earlier in the day may help.
The National Institute of Mental Health notes that it can take time to find the right antidepressant and dose, so steady use and open communication with your provider matter.
Wellbutrin SR and Quitting Smoking
Sustained release of bupropion is also used to help people quit smoking. For this purpose, it is marketed under a different name, but it contains the same active ingredient. The medication helps reduce nicotine cravings and improve withdrawal symptoms, making it easier for some people to quit.
According to clinical guidelines, the treatment is typically started a week or two before their planned quit date, so it has time to reach effective levels. If you want to stop smoking, ask your healthcare provider whether bupropion could be an appropriate part of your treatment plan.
Wellbutrin SR and Weight Gain
Weight changes are a common concern with antidepressants, since some can cause weight gain. Bupropion is generally not associated with weight gain. Some people even notice a drop in appetite or modest weight loss, although individual experiences may vary.
Generally weight neutral: Many people experience little or no change in weight while taking bupropion.
May reduce appetite: Some people notice a reduced appetite, especially early on in the treatment.
Individual responses vary: Track your weight changes, even if they’re subtle, and share it with your healthcare provider.
Wellbutrin SR Drug Interactions
Wellbutrin SR can interact with certain medications, supplements, and substances. Before starting treatment, tell your healthcare provider about all medications, over-the-counter (OTC) products, or supplements you’re taking.
Here are a few medications that Wellbutrin SR can interact with:
Monoamine oxidase inhibitors (MAOIs): Wellbutrin SR should not be taken with MAOIs. A waiting period is needed when switching between these medications to reduce the risk of serious side effects.
Medications that increase seizure risk: Combining bupropion with other medications that lower the seizure threshold can further increase the risk of seizures. Your healthcare provider can review your medications and determine whether any adjustments are needed.
Certain other medicines: Bupropion can affect how the body processes some medications, which may increase their levels or require dose adjustments.
Your healthcare provider and pharmacist can help identify potential interactions and make sure your medications can be taken together safely.
If depression is holding you back, you can connect with a licensed psychiatric provider through Blossom Health, covered by in-network insurance, at joinblossomhealth.com/start.
Medical Disclaimer
This article is for educational purposes only and does not constitute medical advice. The information provided should not replace consultation with a qualified healthcare provider. Individual responses to medications can vary significantly, and what applies to one person may not be the same for another.
Always consult with your doctor or pharmacist before making any decisions about medication changes, discontinuation, or interactions with other substances. If you’re experiencing concerning symptoms or side effects, please seek professional help from a healthcare provider.
In case of a medical emergency, contact your local emergency services immediately or call 911. For mental health emergencies, contact the National Suicide Prevention Lifeline at 988.
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