Bupropion: Independent Evidence on Depression, Quitting Smoking & Side Effects

Table of contents

• Evidence summary
• What bupropion is
• How it works
• What it is prescribed for
• What works and what does not
• Benefits by claim
• Risks and all side effects
• All interactions
• Who should avoid bupropion
• Dosage and how to take it
• Follow the money: who makes it and who funded the evidence
• Related research
• Frequently asked questions
• Sources and funding notes

Evidence summary

This table lists the main claims made about bupropion, ranked by the strength of the human evidence behind them. The funding column shows who paid for each source.

Independent evidence and credibility scorecard

Independence tiers: 1 = government regulator or public body; 2 = academic with no relevant industry funding; 3 = academic, but with some industry ties or a manufacturer-dominated trial base; 4 = manufacturer or seller. Credibility A–D reflects method quality plus independence.

What bupropion is

Bupropion hydrochloride is a prescription-only medicine. The UK product information classes it as a centrally acting noradrenaline and dopamine reuptake inhibitor (NDRI), in the pharmacological group "other antidepressants" (ATC code N06AX12) (Zyban SmPC 4.4, 5.1). US labels describe it as an "aminoketone" antidepressant (FDA Wellbutrin XL label). Chemically it resembles amphetamine closely enough that it can cause false-positive amphetamine results on some rapid urine drug screens (SmPC 4.4).

Brand names and formulations

Why UK and US licensing differ

This is the single most important point for UK readers. In the UK, bupropion is marketed as Zyban, and its product information gives a smoking-cessation indication only. The Zyban SmPC says only that bupropion "is indicated for the treatment of depression in some countries" (Zyban SmPC 4.4). The recommendations in NICE's 2022 depression guideline (NG222) do not name bupropion (NICE NG222). Even inside the smoking indication, NICE notes that offering a further course of bupropion to prevent relapse was "an off-label use" in February 2025 (NICE NG209, 1.17.2). A UK prescription of bupropion for depression is therefore off-label, which a specialist can do but which carries extra responsibilities. In the US, by contrast, the same molecule is a mainstream antidepressant.

How it works

Bupropion inhibits the reuptake of noradrenaline and dopamine into nerve cells. It has minimal effect on serotonin reuptake and does not inhibit monoamine oxidase (SmPC 5.1). The FDA label calls it "a relatively weak inhibitor" of noradrenaline and dopamine uptake and says that, as with other antidepressants, its exact mechanism is unknown (FDA label 12.1). The UK label likewise says it is not known how bupropion helps people stop smoking, and only presumes noradrenergic and/or dopaminergic mechanisms (SmPC 5.1). The mechanism was still being debated at a 1995 expert conference convened by company scientists (Ascher et al. 1995).

What the body does with it

The liver breaks bupropion down extensively, mainly through the enzyme CYP2B6, into three active metabolites: hydroxybupropion, threohydrobupropion and erythrohydrobupropion. At steady state, blood levels of these metabolites match or exceed those of bupropion itself. The average half-life of bupropion is about 20 hours, and steady state is reached in 5–8 days (SmPC 5.2). Bupropion and hydroxybupropion both inhibit the enzyme CYP2D6, which drives many of its drug interactions (see below). Because the risk of seizure rises with peak blood levels, all modern formulations release the drug slowly. Crushing, chewing or splitting the tablets can increase side effects, including seizures (SmPC 4.2).

Why it behaves differently from SSRIs

Because bupropion largely spares serotonin, its side-effect pattern differs from sertraline or escitalopram. It tends to cause insomnia and agitation rather than sedation, weight loss rather than gain, and less sexual dysfunction. The same stimulant-like chemistry explains its risks of seizures and raised blood pressure. In people experienced with drugs of abuse, a single 400 mg dose produced "mild amphetamine-like activity" on a standard scale. The FDA considers normal divided doses unlikely to be significantly reinforcing, but misuse by snorting or injection has been reported, with seizures and deaths (FDA label 9.2).

What it is prescribed for

What works and what does not

Benefits by claim

1. Stopping smoking

This is bupropion's best-evidenced use, and the independent case is strong. The Cochrane Tobacco Addiction Group's 2023 update pooled 50 trials with 18,577 participants in which bupropion was the only medicine. It found a risk ratio for long-term abstinence of 1.60 (95% CI 1.49 to 1.72; I² = 16%), graded high certainty (Hajizadeh, Howes et al., Cochrane 2023). The earlier 2020 version, led by Howes, reported RR 1.64 (1.52 to 1.77) across 45 studies and 17,866 participants (Howes et al., Cochrane 2020). Two features make this finding robust against funding bias. The reviewers excluded trials that were funded by industry or used company-supplied medicine, and the result "was not sensitive" to those exclusions. They also found no funnel-plot evidence of publication bias.

In absolute terms, the gain is modest. A 2023 Cochrane component network meta-analysis estimated that bupropion (OR 1.43, 95% CrI 1.26 to 1.62; 71 trials) produces about three additional quitters per 100 (95% CrI 2 to 4). The comparable figures were about eight per 100 for varenicline and nicotine e-cigarettes and seven for cytisine (Lindson et al., Cochrane 2023). In head-to-head trials, bupropion was less effective than varenicline (RR 0.73) and combination NRT (RR 0.74), and similar to a single form of NRT (RR 1.03) (Cochrane 2023). The manufacturer-co-funded EAGLES trial found the same ranking. Bupropion beat placebo (OR 2.07) but was beaten by varenicline (OR 1.75 in varenicline's favour) (Anthenelli et al. 2016). The Cochrane authors concluded that more placebo-controlled trials of bupropion would be unlikely to change the picture, and that the evidence gives "no clear justification" for choosing bupropion over NRT or varenicline. This is why NICE lists it among the less effective options while keeping it available (NICE NG209).

2. Major depression (US licence)

In the Cipriani 2018 network meta-analysis, bupropion's odds ratio for response versus placebo was 1.58 (95% CrI 1.35 to 1.86). That places it in the middle of the 21 antidepressants, whose ORs ranged from 2.13 for amitriptyline to 1.37 for reboxetine. Its odds ratio for dropping out was 0.96 (0.81 to 1.14), statistically no different from placebo (Cipriani et al., Lancet 2018, figure 3). Three honest caveats come from the same paper. First, the authors rated certainty low to very low for most comparisons involving bupropion. Second, smaller and older studies showed larger effects, "in particular for amitriptyline, bupropion, fluoxetine, and reboxetine", a pattern that can inflate estimates. Third, the authors describe the effect sizes across all antidepressants as "mostly modest".

An odds ratio of 1.58 does not mean 58% more people get better. It means the odds of meeting the trial's response threshold (usually a 50% fall in symptom score) are about one and a half times those on placebo. Because many people on placebo also improve in depression trials, the absolute difference is smaller than the ratio suggests. The FDA's own basis for approval is narrow: two 4-week inpatient trials and one 6-week outpatient trial of the old immediate-release tablet. In one of these, only the 450 mg dose, not 300 mg, beat placebo. The label adds that "there are no independent trials demonstrating the efficacy of Wellbutrin XL in the acute treatment of MDD"; its approval rests on showing similar blood levels to the older formulations (FDA label 14.1).

The strongest publicly funded real-world data come from the NIMH-funded STAR*D programme. Among 727 outpatients whose depression had not remitted on citalopram, switching to bupropion SR (up to 400 mg a day) produced remission rates of 21.3% (clinician-rated) and 25.5% (self-rated). These were not significantly different from sertraline or venlafaxine (Rush et al., NEJM 2006). Adding bupropion SR to citalopram gave remission in 29.7%, the same as adding buspirone (30.1%). Bupropion caused fewer dropouts from intolerance (12.5% versus 20.6%) (Trivedi et al., NEJM 2006). The honest reading is that about one in four people who have not responded to one antidepressant will remit on the next. Bupropion is a reasonable option at that step, but it is not a special one.

3. Preventing seasonal (winter) depression

Wellbutrin XL is the only medicine the FDA has licensed to prevent seasonal depressive episodes. Treatment starts in autumn before symptoms and stops in spring. Across three trials, 84.3% of people on bupropion stayed depression-free through winter, against 72.0% on placebo (FDA label 14.2). An independent Cochrane team from Austria re-analysed the same three trials (1,100 people). It found RR 0.56 (0.44 to 0.72) for recurrence, moderate quality. The number needed to treat depends on baseline risk: 8 if 30% of people would otherwise relapse each winter, and 4 if 60% would (Gartlehner et al., Cochrane 2019). The same review reports that all three trials were funded by GlaxoSmithKline, and in two of them all but one author were GSK employees. All three also had high dropout, and bupropion increased headache (RR 1.26), insomnia (RR 1.46) and nausea (RR 1.63). No trial has compared bupropion with light therapy, which remains the first-line treatment for seasonal depression in the CANMAT guideline (CANMAT 2023).

4. Lower sexual side-effect burden

Sexual dysfunction is one of the most common reasons people stop SSRIs. A meta-analysis limited to studies that asked patients directly about sexual function found significantly higher rates with sertraline, venlafaxine, citalopram, paroxetine, fluoxetine and others, ranging from 25.8% to 80.3% of patients. It found no significant difference from placebo for bupropion (Serretti & Chiesa, J Clin Psychopharmacol 2009). The authors note that including open-label studies and mixed rating scales weakens the conclusions. CANMAT 2023, whose guideline process received no industry funding, independently lists bupropion among the antidepressants "associated with lower rates of sexual side effects" (CANMAT 2023). This benefit is real and well supported, but it is not absolute. The FDA label lists decreased libido (3% versus 2% on placebo in the immediate-release trials), and impotence and abnormal ejaculation appear among post-marketing reports (FDA label 6). Bupropion is also not licensed to treat sexual dysfunction. Promoting it for that purpose was one of the unapproved uses in GSK's 2012 guilty plea (US DOJ).

5. Weight

In the manufacturer's short-term depression trials of bupropion SR, weight loss of more than 5 lb (about 2.3 kg) occurred in 14% on 300 mg and 19% on 400 mg, versus 6% on placebo. Weight gain of the same size occurred in 3%, 2% and 4% respectively. In the longer (up to 6 months) seasonal-depression trials, 23% on bupropion lost weight versus 11% on placebo, and 11% gained versus 21% (FDA Wellbutrin XL label, tables 5 and 6). By contrast, CANMAT singles out mirtazapine for "significant increases in appetite, weight gain" (CANMAT 2023). Bupropion's weight-loss tendency is also why it is combined with naltrexone in Contrave, a licensed US weight-management product (Contrave label). Appetite loss is a side effect, not a reason to take it, and eating disorders are an absolute contraindication (see below).

Risks and all side effects

FDA boxed warning: suicidal thoughts and behaviours

Every US bupropion label, including the generic smoking-cessation product, carries the antidepressant class boxed warning. In summary, antidepressants increased the risk of suicidal thoughts and behaviour in children, adolescents and young adults in short-term trials. The trials did not show an increase in people aged 65 and over. Patients of all ages starting antidepressants should be monitored closely for worsening and for new suicidal thoughts, and families and caregivers should be told to watch for them (FDA Wellbutrin XL label, generic SR label). The pooled trials behind the warning showed, per 1,000 patients treated:

• Under 18: 14 additional cases of suicidal thinking or behaviour
• 18–24: 5 additional
• 25–64: 1 fewer
• 65 and over: 6 fewer

The 2016 change to the smoking-cessation warning

Until December 2016, US bupropion labels also carried boxed language about serious neuropsychiatric events in people using it to stop smoking. The FDA removed that language after the EAGLES trial, which the FDA had required the manufacturers to run. The antidepressant-class suicidality warning remained in place (Psychiatric News Alert, APA, 19 December 2016). EAGLES randomised 8,144 smokers in 16 countries. Among those without psychiatric illness, moderate-to-severe neuropsychiatric events occurred in 2.2% on bupropion versus 2.4% on placebo. Among those with psychiatric illness, the figures were 6.7% versus 4.9%, a risk difference of 1.78 percentage points (95% CI −0.24 to 3.81) that was not statistically significant (Anthenelli et al., Lancet 2016). Pfizer and GSK funded the trial, and the confidence interval in the psychiatric group does not rule out a small increase. The independent Cochrane review also found psychiatric adverse events more common on bupropion than placebo (RR 1.25, 1.15 to 1.37; 6 studies) (Howes et al., Cochrane 2020). The current labels still tell patients to stop the medicine and contact a clinician if agitation, depressed mood or unusual changes in thinking or behaviour appear (FDA label 5.2).

Seizures: the defining risk

Bupropion's seizure risk nearly ended its career. The FDA approved Wellbutrin on 30 December 1985 (Drugs@FDA). A multicentre trial in people with bulimia then recorded grand mal seizures in 4 of 55 people given bupropion, "a frequency of seizures far higher than observed in previous studies" (Horne et al., J Clin Psychiatry 1988). The originator, Burroughs Wellcome, then ran a 102-centre prospective study in 3,341 depressed patients at 225–450 mg a day. It observed a seizure rate of 0.24% in the 8-week treatment phase and 0.40% for the whole study (Johnston et al. 1991). That company-run, uncontrolled study is the source of the "0.4% (13/3,200)" figure that still appears in US labels.

Current regulator-approved figures:

• Up to 300 mg/day (SR, or Zyban): about 0.1% (1 in 1,000) (Zyban SmPC 4.4).
• 300–450 mg/day (immediate-release): about 0.4% (FDA label 5.3).
• 450–600 mg/day: the estimated incidence "increases almost tenfold" (FDA label 5.3).

The risk also depends on the person. The UK label requires every patient to be assessed for predisposing factors. These include other medicines that lower the seizure threshold, alcohol misuse, a history of head injury, diabetes treated with insulin or tablets, and use of stimulants or appetite suppressants. If such factors are present, Zyban should be used only with a "compelling clinical justification", and a maximum of 150 mg a day should be considered. Anyone who has a seizure on bupropion must stop and never restart it (SmPC 4.4). The Cochrane review's pooled estimate for seizures in trials was RR 2.93 (0.74 to 11.54). That is too imprecise to confirm or exclude a difference, because seizures are rare and trials exclude high-risk people (Cochrane 2023).

Common side effects

The table shows placebo-controlled depression-trial rates for bupropion SR, at 300 mg/day versus placebo, from the FDA label (FDA label, table 3). In the smoking-cessation population, insomnia is "very common" (more than 1 in 10) (SmPC 4.8). In EAGLES it was the most frequent adverse event on bupropion, at 12% (EAGLES).

In those trials, 9% on 300 mg and 11% on 400 mg stopped because of side effects, versus 4% on placebo (FDA label 6.1). In smoking trials, the independent Cochrane review found dropouts due to adverse events were higher on bupropion (RR 1.44, 1.27 to 1.65; high certainty) (Cochrane 2023).

Serious and rare harms

Withdrawal and dependence

Bupropion appears to cause fewer discontinuation symptoms than many antidepressants. The UK label says discontinuation reactions "are not expected" with Zyban, although a tapering period "may be considered" (SmPC 4.2). CANMAT's table of discontinuation risk puts bupropion in the "low or minimal risk" group, alongside fluoxetine, mirtazapine, vortioxetine and agomelatine (CANMAT 2023). The US label still says to taper: people on 300 mg of Wellbutrin XL should step down to 150 mg before stopping (FDA label 2.5). Bupropion is not a controlled substance in the US. The FDA judges its abuse potential low at normal doses, while noting animal and human signals of stimulant-like effects at high doses (FDA label 9). Stopping the medicine can bring the underlying depression back, which is a separate issue from withdrawal. Stopping should always be planned with the prescriber.

All interactions

Who should avoid bupropion

Absolute contraindications (UK Zyban and US labels)

• A current seizure disorder or any history of seizures (UK). The US label lists seizure disorder and conditions such as severe head injury, arteriovenous malformation, CNS tumour or infection, and severe stroke (SmPC 4.3, FDA 5.3).
• A known brain (CNS) tumour.
• A current or previous diagnosis of bulimia or anorexia nervosa.
• Abrupt withdrawal from alcohol or benzodiazepines (and, in the US, barbiturates and antiepileptics).
• Severe hepatic cirrhosis (UK).
• A history of bipolar disorder (UK), because bupropion may trigger mania.
• Taking an MAOI within the last 14 days (24 hours for a reversible MAOI in the UK).
• Taking any other bupropion-containing medicine.
• Hypersensitivity to bupropion or the tablet ingredients.

Pregnancy and breastfeeding

For smoking cessation, UK advice is clear. The Zyban SmPC says it "should not be used in pregnancy" and that pregnant women should be encouraged to quit without medication (SmPC 4.6). NICE says do not offer bupropion during pregnancy or breastfeeding (NICE NG209, 1.20.11). The birth-defect data are inconsistent. The international pregnancy registry found cardiac defects in 9 of 675 first-trimester exposures (1.3%), similar to the background rate of about 1%. One case-control study found a raised risk of left outflow tract heart defects (adjusted OR 2.6, 95% CI 1.2–5.7), and another found a raised risk of ventricular septal defects (adjusted OR 2.5, 1.3–5.0), but neither result was replicated in the other studies (FDA label 8.1). The US label, written for depression, stresses that untreated depression also carries risks. It cites a study in which women who stopped antidepressants in pregnancy relapsed more often. Bupropion passes into breast milk. The average infant dose was estimated at 2% of the mother's weight-adjusted dose, and seizures have been reported in breastfed infants, though the link is unclear (FDA label 8.2). Decisions in pregnancy and breastfeeding need a prescriber who knows the full history.

Older adults

The UK label recommends 150 mg once a day for older people, because "greater sensitivity in some older individuals cannot be ruled out". Some studies suggest bupropion and its metabolites build up more in older people (SmPC 4.2, 5.2). The US label notes that only 275 of about 6,000 trial participants were 65 or older, and it advises considering kidney function when choosing the dose (FDA label 8.5). CANMAT advises considering sodium monitoring with antidepressants in people aged 60 and over (CANMAT 2023). We could not access the full text of the 2023 AGS Beers Criteria to confirm its bupropion entry, so we do not quote it here.

Liver and kidney problems

• Liver: contraindicated in severe cirrhosis in the UK. For mild to moderate impairment, the UK dose is 150 mg once daily with close monitoring. In severe cirrhosis, bupropion's peak level rose by about 70% and total exposure about threefold (SmPC 4.2, 5.2). The US maximum for moderate to severe impairment is Wellbutrin XL 150 mg every other day (FDA 2.6).
• Kidneys: the metabolites are cleared in urine and may accumulate. The UK dose is 150 mg once daily (SmPC 4.4). The US label says to consider reducing the dose or frequency when GFR is below 90 mL/min (FDA 2.7).

Other groups needing caution

These include people with uncontrolled high blood pressure, recent heart attack or unstable heart disease (no controlled studies), Brugada syndrome or a family history of sudden cardiac death, untreated narrow-angle glaucoma, diabetes treated with insulin or tablets, a history of head injury, or heavy alcohol use. The UK labels, the US labels and NICE all advise against use under 18 (SmPC, FDA label, NICE).

Dosage and how to take it

How to take it

• Swallow the tablets whole. Do not cut, crush or chew them, as this can raise the risk of side effects, including seizures (SmPC 4.2).
• Take with or without food. A high-fat meal modestly raised bupropion levels in studies (SmPC 5.2).
• For twice-daily products, keep at least 8 hours between doses. To reduce insomnia, avoid taking a dose at bedtime (SmPC 4.2). Wellbutrin XL is taken in the morning.
• For smoking cessation, the UK licence says Zyban should be used with motivational support, and NICE advises offering behavioural support whichever option is chosen (NICE NG209, 1.12.6).
• Your blood pressure should be checked before and during treatment (SmPC 4.4).

How long before it works

For smoking, treatment begins before the quit date because it takes about a week to reach steady blood levels (US SR label 2.1; UK steady state 5–8 days, SmPC 5.2). For depression, CANMAT uses early improvement at 2–4 weeks as the checkpoint. A reduction in symptom scores of less than 20% by 4 weeks should prompt the prescriber to consider changing the dose or medicine. In real-world populations, about half of people respond after 8 weeks of an antidepressant (CANMAT 2023).

How to stop

Stop only after discussing it with your prescriber. For Zyban, the licensed course is 7–9 weeks and a taper "may be considered" (SmPC 4.2). For Wellbutrin XL, the US label says to reduce from 300 mg to 150 mg once daily before stopping. In seasonal depression, the dose is tapered in early spring (FDA 2.3, 2.5). If you take digoxin, the dose may need checking after bupropion stops (SmPC 4.5).

Follow the money: who makes it and who funded the evidence

Originator and current owners

• Originator: Burroughs Wellcome Co. (Research Triangle Park, North Carolina, USA). Burroughs Wellcome scientists published the early pharmacology, chemistry and seizure research on bupropion (Johnston et al. 1991, Ascher et al. 1995). The company is now part of GlaxoSmithKline (review noting "Burroughs-Wellcome Company (now GlaxoSmithKline)").
• GlaxoSmithKline (London, UK) holds the UK Zyban licence through Glaxo Wellcome UK Ltd, trading as GlaxoSmithKline UK (SmPC section 7). It is also the US sponsor of the Wellbutrin, Wellbutrin SR and Zyban applications (Drugs@FDA).
• Wellbutrin XL was developed and manufactured by Biovail, a Canadian company, and distributed by GSK in the US from September 2003. In May 2009 Biovail agreed to pay GSK $510 million for full US rights. Its release forecast $90–100 million in revenue from the product in 2009 and $135–145 million in 2010 (Biovail press release, 6 May 2009, hosted by Bausch Health). The current US label lists Bausch Health US (FDA label).
• Combination products: Contrave (naltrexone/bupropion) is labelled by Nalpropion Pharmaceuticals, and Auvelity (dextromethorphan/bupropion) by Axsome Therapeutics (Contrave label, Auvelity label).
• Generics: many US generic manufacturers market bupropion SR and XL, for example under ANDA 206122 and ANDA 079094 (example generic SR label).

Who funded the key evidence

Documented integrity events

• 2012 US criminal plea (Wellbutrin). On 5 July 2012, GlaxoSmithKline LLC pleaded guilty in federal court in Boston and was sentenced for several offences. One was the "illegal off-label promotion" of Wellbutrin. According to the US Attorney's Office, from January 1999 to December 2003 GSK promoted Wellbutrin, then approved only for major depressive disorder, "for weight loss, the treatment of sexual dysfunction, substance addictions and Attention Deficit Hyperactivity Disorder, among other off-label uses". The United States contended that GSK paid doctors to speak at and attend meetings, "sometimes at lavish resorts", and used "sham advisory boards" and "supposedly independent" continuing medical education to promote these uses. GSK pleaded guilty to misbranding Wellbutrin and was fined $554,433,600 for that count. The overall resolution covering Paxil, Wellbutrin and Avandia totalled $1 billion in criminal fines and forfeiture, plus $2 billion in civil payments (US Attorney's Office, District of Massachusetts, 5 July 2012). This matters for readers because two of bupropion's genuine, independently supported advantages, less sexual dysfunction and less weight gain, overlap with uses that were unlawfully promoted. The advantages are real; bupropion is still not licensed to treat those problems.
• 2012 generic quality problem. The first generic 300 mg extended-release bupropion (Budeprion XL, approved 2006) had been approved by extrapolating from a 150 mg bioequivalence study. After FDA received numerous reports of problems when patients switched, it sponsored its own study, and Budeprion XL 300 mg failed bioequivalence testing in 2012. The product was withdrawn in October 2012 (Washington University research protocol NCT02209597, background section). This is a quality event for one generic, not evidence against bupropion itself. It is a reason to tell your prescriber if you notice a change after switching brands.

None of this means the independent evidence above is wrong. The strongest findings on smoking cessation come from NIHR-funded Cochrane reviews that specifically tested for industry influence. The point is to know which findings rest mainly on company data (depression registration trials, SAD prevention, seizure rates, EAGLES) and which have been independently checked.

Related research

• Stress, anxiety and depression prevention guide: the non-drug foundations (CBT skills, exercise, sleep, support)
• Stress, anxiety and depression supplements: the evidence
• St John's wort: a herbal antidepressant with major interaction risks
• Saffron for depression
• L-theanine
• Magnesium
• Ashwagandha: evidence and safety
• Sleep prevention guide and sleep supplements evidence: insomnia is bupropion's most common side effect
• Melatonin: light and timing, relevant to seasonal depression
• Sibling medicine reviews: sertraline, escitalopram, citalopram, fluoxetine, venlafaxine, duloxetine, mirtazapine, varenicline

Frequently asked questions

Sources and funding notes

• Zyban 150 mg prolonged release tablets, Summary of Product Characteristics (emc; text revised 28 August 2026): licence holder Glaxo Wellcome UK Ltd trading as GlaxoSmithKline UK; content approved by the UK regulator (PL 10949/0340).
• Wellbutrin XL (bupropion HCl extended-release) US prescribing information, effective February 2026: labeller Bausch Health US; FDA-approved; trial data are manufacturer-generated.
• Wellbutrin SR US prescribing information, effective November 2025: labeller GlaxoSmithKline; FDA-approved.
• Bupropion hydrochloride extended-release tablets (SR) for smoking cessation, US label (Dr. Reddy's, ANDA 206122): generic manufacturer; FDA-approved labelling.
• Aplenzin (bupropion hydrobromide) US label: Bausch Health US; FDA-approved.
• Contrave (naltrexone/bupropion) US label: Nalpropion Pharmaceuticals; FDA-approved.
• Auvelity (dextromethorphan/bupropion) US label: Axsome Therapeutics; FDA-approved.
• US FDA. Drugs@FDA records for NDA 018644 (Wellbutrin, approved 30 Dec 1985), 020358 (Wellbutrin SR, 4 Oct 1996), 020711 (Zyban, 14 May 1997), 021515 (Wellbutrin XL, 28 Aug 2003): US government regulator; dates retrieved via the openFDA drugsfda dataset.
• NICE NG209. Tobacco: preventing uptake, promoting quitting and treating dependence (last updated 4 February 2025), treating tobacco dependence and pregnancy chapter: UK public body.
• NICE NG222. Depression in adults: treatment and management, recommendations: UK public body; bupropion is not named in the recommendations.
• NHS. NHS stop smoking services help you quit: NHS England; lists bupropion (Zyban) among stop-smoking tablets.
• Cipriani A et al. Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder. Lancet 2018: funded by NIHR Oxford Health Biomedical Research Centre and the Japan Society for the Promotion of Science; some co-authors declared fees from antidepressant manufacturers; UK-led international team.
• Hajizadeh A, Howes S, Theodoulou A, et al. Antidepressants for smoking cessation. Cochrane Database Syst Rev 2023: NIHR (NIHR132114) and Research England; University of Oxford; authors declared no relevant interests.
• Howes S, Hartmann-Boyce J, Livingstone-Banks J, Hong B, Lindson N. Antidepressants for smoking cessation. Cochrane Database Syst Rev 2020: Cochrane Tobacco Addiction Group, University of Oxford (NIHR infrastructure funding).
• Lindson N et al. Pharmacological and electronic cigarette interventions for smoking cessation in adults: component network meta-analyses. Cochrane 2023: NIHR-funded; notes that 118 included trials reported pharmaceutical or e-cigarette/tobacco industry funding.
• Anthenelli RM et al. Neuropsychiatric safety and efficacy of varenicline, bupropion, and nicotine patch (EAGLES). Lancet 2016: funded by Pfizer and GlaxoSmithKline; several authors declared payments from both; 140 centres in 16 countries.
• Psychiatric News Alert (American Psychiatric Association). FDA to remove, update boxed warnings on mental health side effects of Chantix, Zyban. 19 December 2016: professional-society news report of the FDA's decision. The FDA's original communication page could not be retrieved at the time of writing.
• Gartlehner G et al. Second-generation antidepressants for preventing seasonal affective disorder in adults. Cochrane 2019: Cochrane Austria internal funds; one author declared lecture fees from Angelini and Lundbeck; all three included trials were funded by GlaxoSmithKline.
• Rush AJ et al. Bupropion-SR, sertraline, or venlafaxine-XR after failure of SSRIs for depression (STAR*D). NEJM 2006: US NIMH contract N01MH90003.
• Trivedi MH et al. Medication augmentation after the failure of SSRIs for depression (STAR*D). NEJM 2006: US NIMH contract N01MH90003.
• Serretti A, Chiesa A. Treatment-emergent sexual dysfunction related to antidepressants: a meta-analysis. J Clin Psychopharmacol 2009: academic authors (Italy); funding not stated in the abstract reviewed.
• Lam RW et al. CANMAT 2023 update on clinical guidelines for management of major depressive disorder in adults. Can J Psychiatry 2024: internal CANMAT funds, no honoraria, no pharmaceutical funding to CANMAT in 2019–2023; individual author disclosures in the paper.
• Horne RL et al. Treatment of bulimia with bupropion: a multicenter controlled trial. J Clin Psychiatry 1988: multicentre US placebo-controlled trial; funding source not stated in the abstract reviewed.
• Johnston JA et al. A 102-center prospective study of seizure in association with bupropion. J Clin Psychiatry 1991: Burroughs Wellcome Co. (manufacturer-run, uncontrolled).
• Ascher JA et al. Bupropion: a review of its mechanism of antidepressant activity. J Clin Psychiatry 1995: expert panel convened with Burroughs Wellcome authors.
• siRNA genome screening approaches to therapeutic drug repositioning (review, 2013): academic review, cited only for the corporate lineage "Burroughs-Wellcome Company (now GlaxoSmithKline)".
• US Attorney's Office, District of Massachusetts. GlaxoSmithKline pleads guilty and is sentenced to pay one billion dollars in criminal fine and forfeiture. 5 July 2012: US government.
• Biovail Corporation. Biovail announces acquisition of U.S. rights to Wellbutrin XL. 6 May 2009 (Bausch Health investor archive): company press release; revenue figures are company forecasts, not audited results.
• Kharasch ED (Washington University). Bioequivalence and clinical effects of generic and brand bupropion, research protocol NCT02209597 (2015): academic protocol; cited for its background summary of the FDA's Budeprion XL findings.

Last reviewed: 26 September 2026. Educational information from Pure City Research, not medical advice. Medicine decisions belong with a qualified prescriber.