Drug vs. Drug

Wellbutrin SR vs. Wellbutrin XL: Differences, similarities, and which is better for you

Avatar By | January 21, 2020

Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ

Wellbutrin SR and Wellbutrin XL are two prescription medications that can treat symptoms of depression. Both drugs contain the active ingredient, bupropion hydrochloride. Wellbutrin SR and Wellbutrin XL are part of a class of medications called norepinephrine-dopamine reuptake inhibitors (NDRIs). They are also referred to as aminoketone antidepressants.

Wellbutrin SR and Wellbutrin XL have the same mechanism of action. They work by blocking the reuptake of norepinephrine and dopamine in the brain. The increased activity of these neurotransmitters is what helps alleviate symptoms of depression.

What are the main differences between Wellbutrin SR and Wellbutrin XL?

Wellbutrin SR is the brand name for bupropion sustained-release tablets. It was FDA approved in 1996 for the treatment of major depressive disorder. Wellbutrin SR is usually taken as 150 mg twice daily for a total daily dose of 300 mg.

Wellbutrin XL is the brand name for bupropion extended-release tablets. It was FDA approved in 2003 for major depressive disorder and seasonal affective disorder. Wellbutrin XL is absorbed in the body more slowly. Compared to immediate-release and sustained-release bupropion, the XL form releases the drug over a longer period of time. For this reason, Wellbutrin XL is taken as a once-daily tablet.

Main differences between Wellbutrin SR and Wellbutrin XL
Wellbutrin SR Wellbutrin XL
Drug class Norepinephrine-Dopamine Reuptake Inhibitor (NDRI)
Aminoketone antidepressant
Norepinephrine-Dopamine Reuptake Inhibitor (NDRI)
Aminoketone antidepressant
Brand/generic status Brand and generic versions available Brand and generic versions available
What is the generic name? Bupropion HCl, sustained-release Bupropion HCl, extended-release
What form(s) does the drug come in? Oral tablet, sustained-release Oral tablet, extended-release
What is the standard dosage? Starting dose: 150 mg per day
Target dose: 150 mg twice daily
Starting dose: 150 mg once daily
Target dose: 300 mg once daily
How long is the typical treatment? 3 to 6 weeks or longer depending on symptoms 3 to 6 weeks or longer depending on symptoms
Who typically uses the medication? Adults 18 years and older Adults 18 years and older

Conditions treated by Wellbutrin SR and Wellbutrin XL

Both Wellbutrin SR and Wellbutrin XL are indicated to treat symptoms of major depression (otherwise known as major depressive disorder). However, Wellbutrin XL is also approved to prevent seasonal affective disorder. Seasonal affective disorder is a mood disorder that affects some people during seasonal changes. For example, someone who normally doesn’t experience depression throughout the year may feel depressed during the winter. Wellbutrin XL can be started in the fall season to prevent mood changes in the winter.

Bupropion can be used in off-label ways to treat ADHD (attention-deficit hyperactivity disorder), depressive episodes of bipolar disorder, and sexual dysfunction caused by other antidepressants like SSRIs (selective serotonin reuptake inhibitors) and tricyclic antidepressants. Other off-label indications include social phobia and PTSD (post-traumatic stress disorder). Bupropion is sometimes used in combination with naltrexone to treat obesity and weight-related conditions.

Bupropion can help with smoking cessation. Bupropion for smoking cessation is manufactured under a different brand called Zyban. Zyban and Wellbutrin cannot be substituted for one another due to differences in dosing.

Condition Wellbutrin SR Wellbutrin XL
Major depressive disorder (MDD) Yes Yes
Seasonal affective disorder (SAD) prevention Off-label Yes
ADHD Off-label Off-label
Bipolar disorder Off-label Off-label
Obesity Off-label Off-label
Sexual dysfunction Off-label Off-label
PTSD Off-label Off-label
Social phobia Off-label Off-label

Is Wellbutrin SR or Wellbutrin XL more effective?

Wellbutrin SR and Wellbutrin XL are both effective for treating depression. Their uses and differences in dosing hold the most weight when choosing between the two. In a clinical study comparing bupropion SR and bupropion XL, those taking the once-daily bupropion XL experienced lower rates of depression and relapse. Clinical trials found that there was more consistent use with the once-daily pill, most likely due to the ease of use. Those taking the twice-daily bupropion SR may have had more trouble taking both doses consistently.

In a systematic review of bupropion, the XL formulation was found to be favored over placebo for preventing seasonal affective disorder. Controlled trials within the review showed a significant decrease in depressive symptoms in those affected with seasonal affective disorder.

Both forms of Wellbutrin are useful for treating some of the same conditions. As prescription medications, Wellbutrin SR and Wellbutrin XL can only be prescribed after a doctor’s visit. Based on your medical history, you may be prescribed a different antidepressant.

Coverage and cost comparison of Wellbutrin SR vs. Wellbutrin XL

Wellbutrin SR is available as a generic oral tablet. It is usually covered by Medicare and most insurance plans. Brand name Wellbutrin SR can cost an average price of around $516 for a 60-day supply of 150 mg tablets. If you use a SingleCare discount card for generic bupropion, the cost can be reduced to a more affordable price. Purchasing Wellbutrin SR with a discount card can lower the cost to as low as $9 at participating pharmacies.

The generic version of Wellbutrin XL is typically covered by Medicare and other insurance plans. Brand name Wellbutrin XL can have an out-of-pocket cost of over $1000. Using a generic bupropion coupon, the price is only $9-$31. Check to see if your pharmacy accepts SingleCare cards for prescription discounts.

  Wellbutrin SR Wellbutrin XL
Typically covered by insurance? Yes; the generic is covered Yes; the generic is covered
Typically covered by Medicare? Yes; the generic is covered Yes; the generic is covered
Standard dosage 150 mg tablets (60 count) 150 mg tablets (30 count)
Typical Medicare copay $0-$47 $0-$51
SingleCare cost $9 $9-$31

Common side effects of Wellbutrin SR vs. Wellbutrin XL

The most common side effects of Wellbutrin SR and Wellbutrin XL include headache, dry mouth, and nausea. Other side effects involve the CNS (central nervous system) and include dizziness, insomnia, and anxiety.

Wellbutrin can also cause gastrointestinal side effects such as stomach upset and constipation. Other common side effects may include heart palpitations, tremors, tinnitus (ringing in the ears), muscle pain, and rash. Weight loss and weight gain are other possible side effects associated with Wellbutrin.

Serious side effects with Wellbutrin are rare and often associated with overdose. Serious side effects include hallucinations, arrhythmia (heart rhythm problems), low blood pressure, and seizures.

  Wellbutrin SR Wellbutrin XL
Side Effect Applicable? Frequency Applicable? Frequency
Headache Yes 26% Yes 23%
Dry mouth Yes 3% Yes 7%
Nausea Yes 13% Yes 8%
Insomnia Yes 11% Yes 6%
Dizziness Yes 7% Yes 5%
Sore throat Yes 3% Yes 2%
Constipation Yes 10% Yes 7%
Anxiety Yes 5% Yes 3%
Stomach ache Yes 3% Yes 2%
Tinnitus Yes 6% Yes 2%
Tremor Yes 6% Yes 1%
Palpitations Yes 2% Yes 2%
Muscle aches Yes 2% Yes 3%
Sweating Yes 6% Yes 2%
Rash Yes 5% Yes 1%

This may not be a complete list. Consult your doctor or pharmacist for other side effects.
Source: DailyMed (Wellbutrin SR), DailyMed (Wellbutrin XL)

Drug interactions of Wellbutrin SR and Wellbutrin XL

Bupropion is processed in the liver by the CYP2B6 enzyme to form an active metabolite called hydroxybupropion. Drugs that block (inhibit) or stimulate (induce) this enzyme can alter the effects of bupropion. CYP2B6 inhibitors can increase the level of bupropion in the blood which can increase the risk of adverse effects. CYP2B6 inducers can lower blood levels of bupropion and decrease its effectiveness.

Bupropion can also affect the CYP2D6 enzyme and alter the effects of other drugs that are processed by it. Other drugs like monoamine oxidase inhibitors (MAOIs) can increase the risk of hypersensitivity reactions and adverse events. Drugs that lower the seizure threshold can increase the risk of seizures in those taking bupropion.

Drug Drug Class Wellbutrin SR Wellbutrin XL
Ticlopidine
Clopidogrel
CYP2B6 inhibitors Yes Yes
Ritonavir
Lopinavir
Efavirenz
Carbamazepine
Phenytoin
CYP2B6 inducers Yes Yes
Venlafaxine
Nortriptyline
Imipramine
Desipramine
Haloperidol
Risperidone
Thioridazine
Metoprolol
Propafenone
Drugs metabolized by CYP2D6 Yes Yes
Rasagiline
Selegiline
Isocarboxazid
Phenelzine
Monoamine oxidase inhibitors (MAOIs) Yes Yes
Levodopa
Amantadine
Dopaminergic drugs Yes Yes
Theophylline
Aminophylline
Clozapine
Baclofen
Drugs that lower seizure threshold Yes Yes
Digoxin Cardiac glycoside Yes Yes

This may not be a complete list of all possible drug interactions. Consult a doctor with all medications you may be taking.

Warnings of Wellbutrin SR and Wellbutrin XL

Wellbutrin SR and Wellbutrin XL may increase the risk of suicidal thinking and behavior. Like other antidepressants, these medications should be monitored for new or worsening suicidal behavior.

Wellbutrin SR and Wellbutrin XL both have seizure risks, especially at high doses. Those with a history of seizure disorders should consult a doctor before taking Wellbutrin. Taking Wellbutrin can increase the incidence of seizures.

Wellbutrin has other precautions such as increases in blood pressure. Therefore, it’s important to watch blood pressure changes. Those who take blood pressure medications may need to adjust their treatment with their doctor.

The use of bupropion has been known to cause psychiatric reactions such as mania, hallucinations, paranoia, delusions, and changes in mood. Follow up with a doctor if you experience these effects.

Frequently asked questions about Wellbutrin SR vs. Wellbutrin XL

What is Wellbutrin SR?

Wellbutrin SR contains a sustained-release formulation of bupropion. It is a norepinephrine-dopamine reuptake inhibitor (NDRI) that balances neurotransmitters in the brain. It is prescribed twice daily to treat symptoms of depression.

What is Wellbutrin XL?

Wellbutrin XL contains extended-release bupropion. It is released more slowly in the body compared to Wellbutrin SR. Wellbutrin XL is approved to treat depression and prevent seasonal affective disorder. It is prescribed once daily.

Are Wellbutrin SR and Wellbutrin XL the same?

No. Wellbutrin SR and Wellbutrin XL are not the same drug. Wellbutrin XL is the extended-release form of bupropion that lasts longer in the body. They have differences in dosing and approved uses.

Is Wellbutrin SR or Wellbutrin XL better?

Wellbutrin SR and Wellbutrin XL both work to relieve symptoms of depression. Wellbutrin XL may be preferred for its once-daily dosing. It may also be better for treating depression during seasonal changes (seasonal affective disorder).

Can I use Wellbutrin SR or Wellbutrin XL while pregnant?

Wellbutrin SR or Wellbutrin XL should only be used during pregnancy if the potential benefits outweigh the risks. These medications should be discussed with a healthcare provider before using during pregnancy or breastfeeding.

Can I use Wellbutrin SR or Wellbutrin XL with alcohol?

Wellbutrin SR or Wellbutrin XL should not be taken with alcohol. Drinking alcohol can lead to an increased risk of adverse side effects. Alcohol should be avoided with these medications.

Does Wellbutrin affect memory?

Decreased memory is a possible side effect of taking Wellbutrin. However, it may not be as common as other side effects such as dizziness, headache, and dry mouth.

Why does Wellbutrin make me feel high?

Wellbutrin increases the activity of norepinephrine and dopamine in the brain. These neurotransmitters are considered “feel-good” chemicals. This feeling usually occurs after taking a high dose of bupropion.

What does Wellbutrin do to the brain?

Wellbutrin inhibits the reuptake of norepinephrine and dopamine. As a result, the drug enhances the activity of these neurotransmitters. Wellbutrin can be used to treat mental health conditions affected by these chemicals in the brain.

Does Wellbutrin treat anxiety?

Wellbutrin is not approved to treat anxiety. In fact, Wellbutrin may cause anxiety as a side effect. Wellbutrin is primarily used to treat symptoms of depression.