Bupropion Extended Release (Wellbutrin XL)

Antidepressantprescriptionoral · predicted

Once-daily extended-release bupropion. It delays the parent-drug peak to about 5 hours without changing the approximately 21-hour elimination half-life.

Projected serum levels — 150 mg, once daily

Bupropion Extended Release (Wellbutrin XL)
Bupropion Extended Release (Wellbutrin XL) modeled serum levels, 150 mg once daily over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 3 days. 0 12.5 25 37.5 50 Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 3
Bupropion Extended Release (Wellbutrin XL) modeled serum levels with a loading dose of 279 mg, then 150 mg once daily The first dose is larger so levels approach steady state faster. 0 12.5 25 37.5 50 Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule

Maintenance schedule: 150 mg once daily (oral).

Loading schedule: 279 mg on day 1, then 150 mg once daily — reaching therapeutic levels sooner.

Modeled steady state after ~3 days: peak ≈ 35.0 mg, trough ≈ 18.9 mg body load. Population-based estimate over 15 days for a 150 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Antidepressant
Route modeled
Oral
Model confidence
predicted
Half-life
21 h
Common dose
150 mg
Suggested maximum
450 mg/day
Reference dose range
150–450 mg (single dose)
Suggested cadence
once daily

Research behind this entry

  1. A sustained-release bupropion for pharmacologic relapse prevention after smoking cessation: a randomized, controlled trial Hays JT et al. · Annals of Internal Medicine, 2001 DOI

    RCT found sustained-release bupropion significantly delayed smoking relapse, with point-prevalence abstinence rates of 55% at 12 months versus 42% for placebo.

  2. Bupropion-SR, sertraline, or venlafaxine-XR after failure of SSRIs for depression (STAR*D) Rush AJ et al. · New England Journal of Medicine, 2006 DOI

    Landmark STAR*D trial found bupropion was as effective as sertraline and venlafaxine as switch therapy after SSRI failure, with the advantage of less sexual dysfunction.

2 published studies referenced in the app, each with a plain-language summary.