Two medicines, side by side
Bupropion vs mirtazapine
Bupropion and mirtazapine are both labeled for depression. Drugs@FDA records approvals of bupropion since 1985 and of mirtazapine since 1996. Pharmacies paid $0.0785 per bupropion HCl xl 150 mg tablet and $0.063 per mirtazapine 15 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like.
Check it at the source: the bupropion FDA label on DailyMed (effective June 21, 2024); the mirtazapine FDA label on DailyMed (effective August 6, 2025).
Highlights of the bupropion record
Bupropion (Wellbutrin) · label of June 21, 2024
SUICIDAL THOUGHTS AND BEHAVIORS SUICIDALITY AND ANTIDEPRESSANT DRUGS 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 [see Warnings and Precautions (5.1)].
Used for
From the label: indicationsBupropion hydrochloride extended-release tablets (SR) are indicated for the treatment of major depressive disorder (MDD), as defined by the Diagnostic and Statistical Manual (DSM). The efficacy of bupropion in the treatment of a major depressive episode was established in two 4-week controlled inpatient trials and one 6-week controlled outpatient trial of adult subjects with MDD [see Clinical Studies (14)]. […]
On the market
- Earliest approval on file
- December 30, 1985
- Generic labelers
- 69 labelers
- Pharmacy cost
- $0.0785 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 35
Highlights of the mirtazapine record
Mirtazapine (Remeron) · label of August 6, 2025
SUICIDAL THOUGHTS AND BEHAVIORS Antidepressants increased the risk of suicidal thoughts and behaviors in pediatric and young adult patients in short-term studies. Closely monitor all antidepressant-treated patients for clinical worsening, and for emergence of suicidal thoughts and behaviors [see Warnings and Precautions (5.1) ]. REMERON/REMERONSolTab is not approved for use in pediatric patients [see Use in Specific Populations (8.4) ].
Used for
From the label: indicationsREMERON/REMERONSolTab are indicated for the treatment of major depressive disorder (MDD) in adults [see Clinical Studies (14) ]. REMERON/REMERONSolTab is indicated for the treatment of major depressive disorder (MDD) in adults.
On the market
- Earliest approval on file
- June 14, 1996
- Generic labelers
- 36 labelers
- Pharmacy cost
- $0.063 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 5
Source: FDA drug labels via openFDA (Bupropion label of June 21, 2024, Mirtazapine label of August 6, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do bupropion and mirtazapine differ on the record?
How each works, in its label's words: Bupropion, “The exact mechanism of the antidepressant action of bupropion is not known, but is presumed to be related to noradrenergic and/or dopaminergic mechanisms.”; Mirtazapine, “The mechanism of action of mirtazapine for the treatment of major depressive disorder, is unclear.”
Half-life, in each label's words: Bupropion, “The mean elimination half-life (±SD) of bupropion after chronic dosing is 21 (±9) hours, and steady-state plasma …”; Mirtazapine, “Elimination Mirtazapine has a half-life of about 20 to 40 hours following oral administration of REMERON or …”
Both labels carry a boxed warning; the records quote them.
Generics: bupropion since 1999; mirtazapine since 2003 (Drugs@FDA).
| Bupropion | Mirtazapine | |
|---|---|---|
| Labeled for | Depression, Quitting smoking | Depression |
| Pharmacologic class | Aminoketone | n/a |
| How it works (label) | The exact mechanism of the antidepressant action of bupropion is not known, but is presumed to be related to noradrenergic and/or dopaminergic mechanisms. | The mechanism of action of mirtazapine for the treatment of major depressive disorder, is unclear. |
| Half-life (label) | The mean elimination half-life (±SD) of bupropion after chronic dosing is 21 (±9) hours, and steady-state plasma concentrations of bupropion are reached within 8 days. | Elimination Mirtazapine has a half-life of about 20 to 40 hours following oral administration of REMERON or REMERONSolTab. |
| Earliest approval on file (Drugs@FDA) | December 30, 1985 | June 14, 1996 |
| First generic approved | November 29, 1999 | January 24, 2003 |
| Generic labelers (NDC) | 69 labelers | 36 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0785 per tablet (Bupropion HCl xl 150 mg tablet) | $0.063 per tablet (Mirtazapine 15 mg tablet) |
| 12-month price change | -21% | -12% |
| Boxed warning | Yes | Yes |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 35 | 5 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 140,269 | 91,057 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What do the labels say about using others of their kind?
Mirtazapine label, warnings and precautionsIncreased risk when co-administered with other serotonergic drugs (e.g., SSRI, SNRI, triptans), but also when taken alone.
Source: FDA drug labels via openFDA
What next?
- Alternatives to bupropion
- every medicine labeled for the same conditions