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This page shows a quick schedule for this drug. For the guided path — pre-taper risk quiz, formulation-aware steps, and email delivery — start from the main calculator.

Wellbutrin / Zyban (Bupropion) Tapering Guide

Bupropion is an NDRI antidepressant, sold as Wellbutrin for depression and Zyban for smoking cessation. It acts on dopamine and noradrenaline rather than serotonin. This guide and medication taper calculator help you plan how to come off bupropion safely with your prescriber.

Dosage

Immediate-release tablets (for example 75 mg and 100 mg in the US) may be scored; sustained- or extended-release (SR/XL) tablets must not be split or crushed because dumping the dose raises seizure risk. Small steps use IR tablets or a compounded liquid.

Classic discontinuation syndrome is uncommon. Still taper gradually and watch mood for weeks after each change — especially if bupropion was treating depression.

Bupropion taper schedule

Choose a common starting dose to preview the full hyperbolic schedule — free, no email required. This schedule has 9 steps and takes about 16 weeks in total; your prescriber may adjust the pace based on how you feel.

Starting dose

Selected start: 300 mg/day · 1× daily
Taper speed: Moderate
Region (formulations): US; Tablet/liquid products used for dosing tips — not your location. Example uses US formulary; change region in the custom builder.
Modelled occupancy at start: ~64.0%

Limited / derived PET anchor — curve is indicative

Swipe sideways to see every column.

Step	Daily (mg)	How to take it	Per dose × 1/day	Hold (weeks)
0	300	Your current dose — hold steady before step 1.	300 mg × 1	—
1	200	Take 2 × 100 mg Wellbutrin IR tablets (200 mg active ingredient total).	200 mg × 1	2
2	150	Take 2 × 75 mg Wellbutrin IR tablets (150 mg active ingredient total).	150 mg × 1	2
3	125	GPSee liquid / compounding note below	125 mg × 1	2
4	100	Take 1 × 100 mg Wellbutrin IR tablet (100 mg active ingredient total).	100 mg × 1	2
5	75	Take 1 × 75 mg Wellbutrin IR tablet (75 mg active ingredient total).	75 mg × 1	2
6	66.18	GPSee liquid / compounding note below	66.18 mg × 1	2
7	50	Take half of a scored 100 mg tablet (50 mg) ≈ 50 mg active ingredient.	50 mg × 1	2
8	37.5	Take half of a scored 75 mg tablet (37.5 mg) ≈ 37.5 mg active ingredient.	37.5 mg × 1	2

Rows highlighted: larger occupancy drop than target — consider smaller steps or longer holds. If symptoms are intolerable, return to the previous dose and talk to your prescriber.

Steps that cannot be made from whole or half licensed tablets point to the liquid / compounding note below — ask your prescriber before changing how you take your dose.

Want a copy to keep?

The full bupropion schedule is already shown below. Enter your email to also receive a PDF and HTML copy you can save or share with your prescriber — optional, and we never gate the schedule behind it.

It's not a substitute for medical advice. This calculator can help you visualise a tapering schedule but before making any changes to your medication plan it's necessary to consult a medical professional. Ask a psychiatrist — available after you request your protocol.

Dose vs occupancy

This taper is spread across 9 gradual steps. The curve below shows why the last few milligrams matter most: at low doses, small dose changes produce large drops in serotonin-transporter occupancy.

What this shows: the non-linear relationship between dose and serotonin transporter (SERT) occupancy. The curve is flat at high doses — most transporters are already blocked, so a dose cut has little biological impact — and much steeper at low doses, where even a 1–2 mg reduction causes a disproportionately large drop in occupancy. Your taper steps are spaced along this curve so each step removes a similar amount of occupancy.

Modelled Hill-curve occupancy — illustrative only. PET-derived parameters vary by study; your prescriber may use different clinical targets. Small mg changes near zero can still produce large occupancy shifts.

How to Taper Off Bupropion (Wellbutrin / Zyban) Safely

How to taper off bupropion (Wellbutrin; Zyban when used for smoking cessation) safely is different from SSRI deprescribing: it is an NDRI, not primarily serotonergic, so classic brain-zap withdrawal is less common. Seizure-risk thresholds, IR/SR/XL formulations, and dose timing matter more. Coming off bupropion should still be planned with your prescriber rather than stopped abruptly from high XL doses.

People searching how to wean off Wellbutrin or get off antidepressants in the NDRI class should ask which release form they take. Gradual reduction is prudent, especially above 300 mg/day and when combining risk factors.

What coming off bupropion actually feels like, week by week

Some people notice irritability, low mood, insomnia or hypersomnia, headache, and cravings (if used for smoking) after large cuts. Classic SSRI sensory zaps are less typical.

XL/SR kinetics mean changes unfold over days. Irritability in the first week after a cut can be withdrawal-adjacent rather than full depressive relapse — timing still helps.

“Honestly, stopping Wellbutrin was uneventful physically — no zaps. What I watched for was my mood and motivation slipping back over the following weeks.”

— paraphrased from patient forums

“The only complication was the XL tablet — you cannot break it, so my prescriber stepped me down using the different strengths.”

— paraphrased from patient forums

Withdrawal or relapse — how to tell them apart

Any discontinuation symptoms tend to track recent dose cuts; depressive relapse or return of nicotine dependence evolves on a longer timescale. Reinstatement decisions should consider seizure-risk dosing rules (Cosci & Chouinard, 2020 framework still helps symptom timing).

Bupropion taper schedules by starting dose (300, 150, 75 mg)

XL and SR tablets must not be crushed; IR 75 mg tablets are sometimes used for finer steps. Notes high → low.

From 300 mg (XL/SR): how to taper off Wellbutrin 300 mg usually steps to 150 mg before lower intermediates — follow your product's dosing rules.

From 150 mg: a bupropion taper schedule from 150 mg may move toward IR 75 mg twice daily or other clinician-directed steps rather than stopping cold.

From 75 mg (IR): how to taper off Zyban/Wellbutrin at the bottom uses IR flexibility or a supervised stop once stable at low dose — do not invent XL splits.

Build your schedule from your dose →

If it gets worse: pausing and reinstatement

Hold or seek advice if mood, agitation, or sleep destabilise after a cut. Reinstatement must respect maximum doses and seizure-risk guidance — do not leap back to a high XL dose without instruction.

Resume with formulation-appropriate steps only.

Formulations and small doses of bupropion

Never crush SR/XL tablets. Switching to IR for the final steps is a clinician/pharmacist decision.

Keep coming off bupropion inside licensed dosing patterns while the milligram total falls.

The bottom line

Bupropion tapering is NDRI- and formulation-specific more than SSRI-like. Stage XL/SR reductions, use IR only with advice, and wean off Wellbutrin without abrupt high-dose stops.

Milligram scale guidance (advanced — prescriber/pharmacist approval required)

When a dose is below what you can split from a licensed tablet, some people weigh crushed tablet powder. This is not exact chemistry — it is a last resort. Liquid or compounded formulations are safer when available.

Resolution: at least 0.001 g (1 mg) — not a kitchen scale.
Include a calibration weight and use a draft shield if possible.
Weigh on a stable surface; tare your container first.
Crushed tablet weight ≠ exact active ingredient — drug may not be evenly distributed; prefer liquid or compounded specials when available.
Never split enteric-coated (EC) or extended-release (XR) products — discuss with your pharmacist.

Example searches (confirm specs before buying):

Key facts about hyperbolic antidepressant tapering

The calculator algorithm is based on peer-reviewed research and has been reviewed by our medical advisors to ensure the accuracy of the tapering model.

72%
discontinued their antidepressant using hyperbolic tapering strips in a real-world study
71% of the same people had previously tried to stop at least once and been unsuccessful; the study did not record which method those earlier attempts used. Figures come from tapering-strip research and may not generalise to every taper.
Source: Groot et al., Therapeutic Advances in Psychopharmacology 2021
56 days
median taper length in that tapering-strip study — not a target; many people taper over 6–12 months or longer
This median reflects tapering-strip use in one study. Your timeline depends on how long you have taken the medication, your withdrawal symptoms, and previous attempts — slower is often safer.
Source: Groot et al., Therapeutic Advances in Psychopharmacology 2021
10%
serotonin transporter occupancy per tapering step
This linear reduction prevents withdrawal. Slower, more gradual tapering over several months has shown greater success in reducing withdrawal symptoms than short tapers.
Source: Horowitz et al., The Lancet Psychiatry 2019

Claro — tapering companion

A protocol isn’t enough — you need support.

Tapering can take months, sometimes years. Claro helps you track each step, log symptoms, and spot when a reduction was too fast — with psychiatrist-reviewed guidance. Join early access while we launch the app.

Why an AI companion for tapering? →

Frequently asked questions about bupropion

Common questions about how to taper off bupropion, hyperbolic schedules, and withdrawal — written for people who want to come off antidepressants safely with their prescriber.

Do you need to taper off bupropion (Wellbutrin)?

Bupropion acts on dopamine and noradrenaline, not serotonin, so it rarely causes the classic discontinuation syndrome — many people stop with few physical symptoms. A gradual taper is still sensible mainly to monitor for a return of depression. Never split or crush XL/SR tablets; use immediate-release tablets or a compounded liquid to make smaller steps.

Why can’t you split Wellbutrin XL or SR tablets?

Wellbutrin XL and SR tablets have a controlled-release coating that spreads the dose over the day. Splitting or crushing them can release the whole dose at once, which raises the risk of seizures — a known dose-related bupropion side effect. To taper, step down using the manufactured strengths, switch to immediate-release tablets, or use a compounded liquid.

Does bupropion cause withdrawal symptoms?

Bupropion has a low withdrawal-severity rating, so significant discontinuation symptoms are uncommon. When symptoms do occur they are usually mild — irritability, low energy, poor concentration or disturbed sleep. Over the weeks after stopping, the more important thing to watch is mood, since a gradual return of depression is more likely than a withdrawal reaction.

What is an antidepressant tapering calculator?

An antidepressant tapering calculator is a free online medication taper calculator that turns your current dose into a step-by-step plan for reducing it over time. The Claro calculator uses the hyperbolic method: each step removes a similar percentage of receptor occupancy rather than the same number of milligrams. The result is a personalised schedule you can review with your prescriber when you decide to wean off antidepressants.

Why use a tapering calculator?

A medication taper calculator turns receptor-occupancy research into a concrete hyperbolic taper schedule you can read in minutes. It is especially useful when you want to come off antidepressants gradually, because the last few milligrams cause the largest change in modelled occupancy. Use it to preview steps, plan liquid or split-tablet doses, and bring a printable plan when you wean off antidepressants with your prescriber.

How does an antidepressant taper calculator work?

The calculator models how much of your serotonin (or noradrenaline) transporter is occupied at each dose using a Hill-equation curve fitted to published PET studies. It then chooses dose reductions so that each step removes a roughly equal amount of occupancy — the hyperbolic method described by Horowitz and Taylor (2019). The schedule is then rounded to doses you can actually achieve with available tablets, capsules, or liquids in your region.

What is hyperbolic tapering and why is it recommended?

Hyperbolic tapering means reducing your dose by smaller and smaller milligram amounts as you get lower, so the change in receptor occupancy at each step stays about the same. It is recommended because antidepressants follow a hyperbolic dose-response curve: at low doses, small milligram changes have outsized effects. Hyperbolic tapering is endorsed in the Maudsley Deprescribing Guidelines (2024), the UK NICE NG222 guideline, and the Dutch multidisciplinary deprescribing document.

What is the safest way to taper off antidepressants?

The safest way is gradual, supervised, and individualised. Work with a prescriber, hold each dose for at least 2-4 weeks before reducing again, and use liquid or compounded formulations once tablets cannot be split small enough. If symptoms become severe, return to the previous stable dose, allow time to settle, then resume with smaller steps. This calculator is educational; do not change medication without clinical supervision.

How slowly should antidepressants be reduced?

Most people benefit from reductions of around 5-10% of the previous dose every 2-4 weeks, and even more slowly toward the end of the taper. Higher-risk drugs — paroxetine, venlafaxine, and duloxetine — typically need slower steps and longer holds. There is no fixed timeline: many people take 6-12 months to fully get off antidepressants and some take longer, especially after years of treatment.

What are common antidepressant withdrawal symptoms?

The most commonly reported antidepressant withdrawal symptoms include dizziness, "brain zaps" (brief electric-shock sensations), nausea, fatigue, insomnia, vivid dreams, headaches, irritability, anxiety, and mood swings. A 2024 Lancet Psychiatry meta-analysis (Henssler et al.) estimated discontinuation symptoms in around 31% of people, with about 2.8% experiencing severe symptoms. Earlier work (Davies & Read, 2019) reported higher rates of 56% across surveyed populations.

What is the difference between antidepressant withdrawal and relapse?

Withdrawal usually starts within days of a dose reduction, includes physical symptoms like dizziness or brain zaps, and improves when you reinstate the previous dose. Relapse of the original condition typically appears weeks later, is dominated by your original symptoms, and is not relieved within hours by reinstating. The Cosci & Chouinard (2020) framework is the standard taxonomy clinicians use to tell the two apart.

Is it dangerous to stop antidepressants cold turkey?

Stopping antidepressants cold turkey is widely discouraged. Sudden discontinuation increases the risk of severe withdrawal symptoms, including dizziness, brain zaps, and emotional changes, and can trigger reinstatement. Short half-life drugs such as paroxetine and venlafaxine carry the highest risk. If you have already stopped abruptly and feel unwell, contact your prescriber; reinstating the previous dose and then tapering more gradually is the standard recommendation.

Why are the last antidepressant dose reductions often the hardest?

Because the dose-occupancy curve is hyperbolic. At low doses, a 1-2 mg change can produce as much receptor change as a 10-20 mg change at higher doses. This is why people often feel fine for most of the taper and then struggle at the end. A medication taper calculator addresses this by making the final steps in tenths of a milligram, which usually requires a liquid formulation or compounded preparation.

Which antidepressants are hardest to taper off?

Paroxetine (Paxil/Seroxat) and venlafaxine (Effexor) are most often reported as the hardest antidepressants to come off, followed by duloxetine (Cymbalta). They share short half-lives and steep dose-occupancy curves, so missed doses or sharp reductions can trigger withdrawal symptoms within days. Fluoxetine (Prozac), with its very long half-life, is generally the easiest and is sometimes used as a "bridge" when switching off shorter-acting drugs.

Need a different dose or speed?

Use the guided builder to enter your current dose, region, and taper preset — then email your personalised protocol.

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Clinical references

[1]Horowitz MA, Taylor D. Tapering of SSRI treatment to mitigate withdrawal symptoms. The Lancet Psychiatry 2019.doi:10.1016/S2215-0366(19)30032-XProposes hyperbolic dose reduction based on receptor-occupancy curves; the methodological basis of every modern taper calculator.
[2]Horowitz MA, Taylor D. The Maudsley Deprescribing Guidelines. Wiley 2024.doi:10.1002/9781394291052Per-drug operational manual for hyperbolic tapering across SSRIs, SNRIs, benzodiazepines, gabapentinoids, and antipsychotics.
[3]Davies J, Read J. A systematic review into the incidence, severity and duration of antidepressant withdrawal effects. Addictive Behaviors 2019.doi:10.1016/j.addbeh.2018.08.027Systematic review: 56% of people who discontinue antidepressants experience withdrawal effects; 46% rate them as severe.
[4]Henssler J et al. Incidence of antidepressant discontinuation symptoms: a systematic review and meta-analysis. The Lancet Psychiatry 2024.doi:10.1016/S2215-0366(24)00133-0Meta-analysis of 79 studies (≈21,000 patients): pooled incidence of discontinuation symptoms ~31%; severe symptoms ~2.8%.
[5]Groot PC, van Os J. Successful use of tapering strips for hyperbolic reduction of antidepressant dose: a cohort study. Therapeutic Advances in Psychopharmacology 2021.doi:10.1177/2045125321103932772% of patients successfully discontinued antidepressants after switching to the hyperbolic model; 71% had previously failed to come off without tapering strips.
[6]Groot PC, van Os J. Antidepressant tapering strips to help people come off medication: real-world outcomes. Therapeutic Advances in Psychopharmacology 2023.doi:10.1177/20451253231171518Of 1,194 patients using hyperbolic taper strips after previous failed attempts, ~71% successfully discontinued their antidepressant.
[7]Framer A. What I have learnt from helping thousands of people taper off antidepressants and other psychotropic medications. Therapeutic Advances in Psychopharmacology 2021.doi:10.1177/2045125321991274Describes the "windows and waves" pattern of withdrawal recovery and supports patient-led pacing.
[8]Hengartner MP et al. Protracted withdrawal syndrome after stopping antidepressants: a descriptive quantitative analysis of consumer narratives. Therapeutic Advances in Psychopharmacology 2020.doi:10.1177/2045125320967183Descriptive analysis of 69 protracted withdrawal cases: median duration 79 weeks; 47% report suicidality during withdrawal.
[9]Cosci F, Chouinard G. Acute and persistent withdrawal syndromes following discontinuation of psychotropic medications. Psychotherapy and Psychosomatics 2020.doi:10.1159/000506868Taxonomy distinguishing new withdrawal symptoms, rebound, and persistent post-withdrawal disorder; the standard framework for withdrawal vs. relapse.
[10]Kalfas M et al. Incidence and Nature of Antidepressant Discontinuation Symptoms. JAMA Psychiatry 2025.doi:10.1001/jamapsychiatry.2025.1362Recent meta-analysis: dizziness was the most common discontinuation symptom in the first 2 weeks after stopping antidepressants, followed by nausea, vertigo, and nervousness.
[11]Gabriel M, Sharma V. Antidepressant discontinuation syndrome. Canadian Medical Association Journal 2017.doi:10.1503/cmaj.160991Clinical review of antidepressant discontinuation syndrome: onset within days of dose reduction, typical symptom course, and management.
[12]Papp A, Onton J. Brain Zaps: An Underappreciated Symptom of Antidepressant Discontinuation. The Primary Care Companion for CNS Disorders 2018.doi:10.4088/pcc.18m02311Characterises "brain zaps" — brief electric-shock sensations — as a common antidepressant discontinuation symptom.
[13]Wang J, Cosci F. Acute and persistent withdrawal syndromes following discontinuation of antidepressants in children and adolescents: a systematic review. Therapeutic Advances in Psychopharmacology 2025.doi:10.1177/20451253251404780Systematic review of acute and persistent antidepressant withdrawal syndromes; reinforces reducing only when stable and under supervision.
[14]Horowitz M, Taylor D. Distinguishing relapse from antidepressant withdrawal: clinical practice and antidepressant discontinuation studies. BJPsych Advances 2022.doi:10.1192/bja.2021.62Frames how clinicians can distinguish antidepressant withdrawal from relapse of the underlying condition.
[15]Sørensen A, Ruhé HG, Munkholm K. The relationship between dose and serotonin transporter occupancy of antidepressants — a systematic review. Molecular Psychiatry 2021.doi:10.1038/s41380-021-01285-wSystematic review of dose–SERT-occupancy relationships across antidepressants; confirms the hyperbolic curve underlying proportional tapering.
[16]Reeve R, Turner JR. Pharmacodynamic models: parameterizing the Hill equation, Michaelis-Menten, the logistic curve, and relationships among these models. Journal of Biopharmaceutical Statistics 2013.doi:10.1080/10543406.2012.756496Explains how the Hill equation, Michaelis-Menten, and logistic models relate — the mathematical basis for the occupancy curve used here.
[17]Preskorn SH. The use of biomarkers in psychiatric research: how serotonin transporter occupancy explains the dose-response curves of SSRIs. Journal of Psychiatric Practice 2012.LinkShows how SERT occupancy explains the non-linear dose–response curves of SSRIs.
[18]Cohrs D, Shapiro B. The relationship between SERT occupancy and extracellular serotonin concentration is hyperbolic, not linear: implications for safely tapering SRI antidepressants. SSRN (preprint) 2026.doi:10.2139/ssrn.6176553Argues the SERT-occupancy to serotonin relationship is itself hyperbolic, reinforcing proportional (hyperbolic) tapering.
[19]Moncrieff J et al. Evidence on antidepressant withdrawal: an appraisal and reanalysis of a recent systematic review. Psychological Medicine 2025.doi:10.1017/S0033291725100652Reappraisal of recent withdrawal-incidence evidence; relevant to how withdrawal rates are interpreted.
[20]Wilson E, Lader M. A review of the management of antidepressant discontinuation symptoms. Therapeutic Advances in Psychopharmacology 2015.doi:10.1177/2045125315612334Practical review of how to manage antidepressant discontinuation symptoms, including tapering and reinstatement.
[21]Groot PC, van Os J. Outcome of antidepressant drug discontinuation with tapering strips after 1–5 years. Therapeutic Advances in Psychopharmacology 2020.doi:10.1177/2045125320954609Long-term follow-up (1–5 years) of patients who discontinued antidepressants using hyperbolic taper strips.
[22]Gury C, Cousin F. Pharmacokinetics of SSRI antidepressants: half-life and clinical applicability. L'Encéphale 1999.LinkHalf-life data for SSRIs — explains why short-half-life drugs (paroxetine, venlafaxine) provoke faster withdrawal.
[23]Mayo Clinic. Antidepressant withdrawal: Is there such a thing?. Mayo Clinic — Expert Answers 2024.LinkPatient-facing explainer on antidepressant discontinuation symptoms and gradual tapering.
[24]NHS Scotland — Right Decision Service. Antidepressants — quality prescribing: difficulty withdrawing from an SSRI/SNRI. NHS Scotland 2024.LinkNHS Scotland guidance on recognising and managing difficulty withdrawing from SSRIs/SNRIs.
[25]The Carlat Psychiatry Report. Clinical pearls for hyperbolic tapering of psychiatric medications in older adults. The Carlat Report 2024.LinkPractical clinical pearls for applying hyperbolic tapering, including in older adults.
[26]Royal College of Psychiatrists. Stopping antidepressants — information for patients and carers. Royal College of Psychiatrists 2024.LinkRCPsych patient-facing guidance on coming off antidepressants safely.
[27]National Institute for Health and Care Excellence (NICE). Depression in adults: treatment and management. NICE guideline [NG222]. NICE 2022.LinkUK national guideline endorsing proportional (hyperbolic) tapering and the use of liquid formulations to enable small final doses.
[28]Royal College of Psychiatrists. Stopping antidepressants — position statement (CR225). Royal College of Psychiatrists 2020.LinkRCPsych acknowledges withdrawal can be severe and long-lasting; recommends slow, individualised tapers.
[29]NHG et al. Multidisciplinary document: Discontinuation of SSRIs and SNRIs (2018; revised 2023). Multidisciplinary Document (Netherlands) 2018.LinkFirst national guideline to explicitly endorse hyperbolic tapering and the use of taper strips (compounded by Regenboog Apotheek).
[30]Medicines and Healthcare products Regulatory Agency (MHRA). Summary of Product Characteristics — SSRI and SNRI products (UK). electronic Medicines Compendium (emc) 2023.LinkAuthoritative UK formulary data (tablet strengths, oral solutions) used to validate the UK region in the calculator.
[31]U.S. Food and Drug Administration. Prescribing information (Structured Product Labeling) for SSRI/SNRI products. FDA / DailyMed 2024.LinkAuthoritative US formulary data (tablet strengths, oral solutions/concentrates) used to validate the US region in the calculator.
[32]Health Canada. Health Canada — Drug Product Database. Health Canada 2024.LinkAuthoritative Canadian formulary data used to validate the Canada region in the calculator.
[33]Therapeutic Goods Administration (TGA). Therapeutic Goods Administration — Australian Register of Therapeutic Goods (ARTG). TGA / ARTG 2024.LinkAuthoritative Australian formulary data used to validate the Australia region in the calculator.
[34]College ter Beoordeling van Geneesmiddelen (CBG-MEB). CBG-MEB — Medicines Information Bank (Netherlands). CBG-MEB 2024.LinkAuthoritative Dutch formulary data; cross-checked with Regenboog Apotheek taper-strip availability.
[35]Regenboog Apotheek, Cinetto. Taperingstrip.com — Regenboog Apotheek. Patient resource (NL) 2024.LinkPioneer of standardised taper strips referenced in the Dutch national guideline.

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