Do you stop smoking before starting the tablet?

No. The label describes starting treatment while still smoking and setting a quit date in the second week, because the medicine needs time to reach a steady level first.

The label contraindicates it in people with a seizure disorder and in combination with MAOIs, among others. This is the part of the consultation that decides whether the medicine is an option at all.

Why is there a boxed warning about mood?

Because the same substance is used as an antidepressant, and the boxed warning about suicidal thoughts and behaviours carried by that class appears on this label as well, even though this strength is not indicated for depression.

Bupropion

A tablet approved as an aid to stopping smoking, started while a person is still smoking and continued for weeks after the quit date.

Class: Aminoketone
Sold as: Sold as: Zyban, Wellbutrin SR; Prescription only

Boxed warning

WARNING: SUICIDAL THOUGHTS AND BEHAVIORS S UICIDALITY AND ANTIDEPRESSANT DRUGS

Although bupropion hydrochloride extended-release tablets (SR) are not indicated for treatment of depression, it contains the same active ingredient as the antidepressant medications WELLBUTRIN ®, WELLBUTRIN SR ®, and WELLBUTRIN XL ®. Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term trials. These trials did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in subjects over age 24; there was a reduction in risk with antidepressant use in subjects aged 65 and older.

From the approved label

Bupropion hydrochloride SR

Approved uses: Bupropion Hydrochloride Extended-Release Tablets (SR) are an aminoketone agent indicated as an aid to smoking cessation treatment.
Forms and strengths: 150 mg - purple, film coated, round, biconvex tablets, debossed with "YH" and "111" on one side and plain on the other side.
Tablets: 150 mg.
How it is taken: Starting dose: 150 mg per day for first 3 days.
General: Increase dose gradually to reduce seizure risk.
Begin dosing one week before quit day.
After 3 days, increase the dose to 300 mg per day, given as 150 mg twice daily at an interval of at least 8 hours.
May be used with a nicotine transdermal system.
Moderate to severe hepatic impairment: 150 mg every other day.
Must not be used when: Bupropion Hydrochloride Extended-Release Tablets (SR) are contraindicated in patients with a seizure disorder.
The use of MAOIs (intended to treat psychiatric disorders) concomitantly with Bupropion Hydrochloride Extended-Release Tablets (SR) or within 14 days of discontinuing treatment with Bupropion Hydrochloride Extended-Release Tablets (SR) is contraindicated.
Interactions: CYP2B6 inducers: Dose increase may be necessary if coadministered with CYP2B6 inducers (e.g., ritonavir, lopinavir, efavirenz, carbamazepine, phenobarbital and phenytoin) based on clinical response, but should not exceed the maximum recommended dose.
Drugs metabolized by CYP2D6: Bupropion inhibits CYP2D6 and can increase concentrations of: antidepressants (e.g., venlafaxine, nortriptyline, imipramine, desipramine, paroxetine, fluoxetine, sertraline), antipsychotics (e.g., haloperidol, risperidone, thioridazine), beta-blockers (e.g., metoprolol), and Type 1C antiarrhythmics (e.g., propafenone, flecainide).
Digoxin: May decrease plasma digoxin levels. Monitor digoxin levels.
Drugs that lower seizure threshold: Dose bupropion hydrochloride extended-release tablets (SR) with caution.
Dopaminergic drugs (levodopa and amantadine): Central nervous system (CNS) toxicity can occur when used concomitantly with bupropion hydrochloride extended-release tablets (SR).
MAOIs: Increased risk of hypertensive reactions can occur when used concomitantly with bupropion hydrochloride extended-release tablets (SR).
Warnings and precautions: Neuropsychiatric adverse events: Postmarketing reports of serious or clinically significant neuropsychiatric adverse events have included changes in mood (including depression and mania), psychosis, hallucinations, paranoia, delusions, homicidal ideation, aggression, hostility, agitation, anxiety, and panic, as well as suicidal ideation, suicide attempt, and completed suicide.
Seizure risk: The risk is dose-related. Can minimize risk by gradually increasing the dose and limiting daily dose to 300 mg. Discontinue if seizure occurs.
Hypertension: Bupropion hydrochloride extended-release tablets (SR) can increase blood pressure. Monitor blood pressure before initiating treatment and periodically during treatment, especially if used with nicotine replacement.
Activation of mania/hypomania: Screen patients for bipolar disorder and monitor for these symptoms.
Psychosis and other neuropsychiatric reactions. Instruct patients to contact a healthcare professional if reactions occur.
Angle-closure glaucoma: Angle-closure glaucoma has occurred in patients with untreated anatomically narrow angles treated with antidepressants.
Common side effects: Most common adverse reactions (incidence ≥5% and ≥1% more than placebo rate) are insomnia, rhinitis, dry mouth, dizziness, nervous disturbance, anxiety, nausea, constipation, and arthralgia.
most common adverse events in subjects treated with bupropion hydrochloride extended-release tablets (SR) were broadly similar to those observed in premarketing studies.
Pregnancy: Pregnancy Category C. Risk Summary Data from epidemiological studies of pregnant women exposed to bupropion in the first trimester indicate no increased risk of congenital malformations overall. All pregnancies, regardless of drug exposure, have a background rate of 2% to 4% for major malformations, and 15% to 20% for pregnancy loss.
How it acts: The exact mechanism by which bupropion hydrochloride extended-release tablets (SR) enhances the ability of patients to abstain from smoking is not known but is presumed to be related to noradrenergic and/or dopaminergic mechanisms. Bupropion is a relatively weak inhibitor of the neuronal reuptake of norepinephrine and dopamine, and does not inhibit the reuptake of serotonin. Bupropion does not inhibit monoamine oxidase.

Label holder:: Epic Pharma, LLC
Label version:: 28 February 2026

This section reports the approved product information. The wording is condensed from the regulator's own summary, and the full document is linked under Sources.

Written by us

How it works

Bupropion acts on the reuptake of dopamine and noradrenaline, and the same substance is approved elsewhere for depression. The label for this strength is explicit that it is indicated as an aid to smoking cessation treatment, which is the difference between this page and the antidepressant of the same name.

Original and generic

The substance is off patent, and the sustained release tablet used for stopping smoking is widely available as a generic. Zyban is the brand name under which it was sold for this use.

What it costs

A course runs for weeks rather than days, so the cost is that of the whole course and not of a single pack. It sits close to varenicline in price in most European markets.

How to get it legally

Prescription only in Europe and the United States. Stopping smoking is one of the clearer uses for a remote consultation, since the decision rests on history and on contraindications rather than on an examination. The contraindications are the substance of that conversation, not a formality.

Questions

Do you stop smoking before starting the tablet?: No. The label describes starting treatment while still smoking and setting a quit date in the second week, because the medicine needs time to reach a steady level first.
Who cannot take it?: The label contraindicates it in people with a seizure disorder and in combination with MAOIs, among others. This is the part of the consultation that decides whether the medicine is an option at all.
Why is there a boxed warning about mood?: Because the same substance is used as an antidepressant, and the boxed warning about suicidal thoughts and behaviours carried by that class appears on this label as well, even though this strength is not indicated for depression.

Sources

Bupropion Hydrochloride SR: prescribing informationDailyMed, US National Library of Medicine. Label version 28 February 2026
Drugs@FDA: ANDA216766US Food and Drug Administration