Wellbutrin vs Lexapro
An NDRI and an SSRI — two antidepressants from entirely different drug classes that affect different neurotransmitters, producing distinct side effect profiles and clinical strengths.
| Category | Wellbutrin | Lexapro |
|---|---|---|
| Generic name | Bupropion hydrochloride | Escitalopram oxalate |
| Drug class | NDRI (norepinephrine-dopamine reuptake inhibitor); aminoketone antidepressant | SSRI (selective serotonin reuptake inhibitor) |
| Primary use | Major depressive disorder, seasonal affective disorder, smoking cessation (Zyban) | Major depressive disorder, generalized anxiety disorder |
| How it works | Inhibits reuptake of norepinephrine and dopamine; no significant serotonergic activity | Inhibits serotonin reuptake transporter (SERT) with high selectivity; also binds allosteric SERT site |
| Onset of action | 2–4 weeks; full effect 6–8 weeks | 2–4 weeks; full effect 6–8 weeks |
| Duration | Daily dosing; XL formulation provides 24-hour coverage | Daily dosing; half-life ~27–32 hours |
| Available forms | Immediate-release tablets (75mg, 100mg); sustained-release SR (100mg, 150mg, 200mg); extended-release XL (150mg, 300mg, 450mg) | Tablets (5mg, 10mg, 20mg); oral solution |
| Controlled substance | No | No |
| Common side effects | Insomnia, dry mouth, headache, nausea, agitation, increased sweating, seizure risk at high amounts; low sexual side effects; weight neutral to weight reducing | Nausea, insomnia, fatigue, sexual dysfunction (common), weight gain possible, headache, sweating |
Overview
Wellbutrin (bupropion) and Lexapro (escitalopram) are both antidepressants, but they belong to entirely different drug classes and work through different neurotransmitter systems. This makes their comparison particularly informative: unlike comparing two SSRIs (which differ mainly in subtle pharmacokinetic ways), comparing Wellbutrin to Lexapro involves contrasting fundamentally different pharmacological approaches to treating depression.
Lexapro is one of the most widely prescribed SSRIs, known for its high selectivity for the serotonin transporter and its relatively clean side effect profile within the SSRI class. Wellbutrin is an aminoketone antidepressant that primarily enhances dopaminergic and noradrenergic transmission, with no meaningful effect on serotonin — making it stand out among antidepressants for its absence of sexual side effects and its potential to support smoking cessation.
How Each Works
Escitalopram (Lexapro) selectively blocks the serotonin reuptake transporter (SERT), preventing serotonin from being recycled from the synapse back into the presynaptic neuron. This increases serotonin availability in the synaptic cleft, gradually enhancing serotonergic neurotransmission in circuits that regulate mood, anxiety, and emotional processing. Escitalopram is the S-enantiomer of citalopram and additionally binds to an allosteric site on SERT, which is thought to make its serotonin reuptake inhibition more complete and sustained.
Bupropion (Wellbutrin) works through an entirely different system. It inhibits the reuptake of dopamine and norepinephrine — not serotonin. By blocking the dopamine transporter (DAT) and norepinephrine transporter (NET), it increases the availability of these catecholamines in the synapse. Dopamine plays a key role in motivation, reward, and energy, while norepinephrine is important for alertness and mood. This combination accounts for bupropion's energizing, activating character and explains why it is effective not only for depression but also for smoking cessation (marketed as Zyban for this purpose) and why it is sometimes used to support weight management.
Key Differences: Sexual Side Effects and Weight
One of the most clinically significant distinctions between these two medications is their effect on sexual function. SSRIs like Lexapro commonly cause sexual side effects — reduced libido, difficulty achieving orgasm, and erectile dysfunction — in a substantial proportion of patients (estimates range from 30–70% in some studies). These effects are related to elevated serotonin activity in pathways that inhibit sexual function.
Bupropion, because it does not affect serotonin, has a much lower rate of sexual side effects. In fact, bupropion is sometimes added to an SSRI regimen specifically to counteract SSRI-induced sexual dysfunction — a well-recognized clinical strategy. For patients who have discontinued antidepressants specifically because of sexual side effects, Wellbutrin may be a more tolerable alternative.
Similarly, SSRIs are associated with weight gain over long-term use for many patients. Bupropion tends to be weight-neutral or mildly weight-reducing, which is why it is also used (as Contrave, combined with naltrexone) for weight management. For patients concerned about weight, this distinction may be relevant to discuss with their doctor.
Anxiety Considerations
Lexapro holds FDA approvals for both major depressive disorder and generalized anxiety disorder, and its serotonergic mechanism broadly addresses anxiety. Wellbutrin does not have an FDA approval for anxiety disorders, and its dopamine/norepinephrine-enhancing, activating nature can actually worsen anxiety or agitation in some patients, particularly when starting treatment or increasing the amount. For patients with significant anxiety alongside depression, this is an important distinction that a doctor must weigh carefully.
Seizure Risk
Bupropion carries a dose-related risk of seizures that is not seen with escitalopram. This risk is especially relevant at higher amounts or in patients with predisposing factors (history of seizures, eating disorders causing electrolyte abnormalities, or alcohol dependence). Bupropion is contraindicated in patients with a seizure disorder or current or prior diagnosis of bulimia nervosa or anorexia nervosa specifically because of this risk.
Which Is Right for You?
Wellbutrin and Lexapro are not interchangeable. The choice between them depends on the symptom profile (depression with or without significant anxiety), history of sexual side effects with prior antidepressants, weight concerns, smoking cessation goals, seizure history, and other factors. Many patients do well with one and not the other, and some may eventually be prescribed both together under medical supervision. Only a doctor or psychiatrist familiar with your complete history can make this determination.
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Wellbutrin (bupropion) is notable among antidepressants for its low rate of sexual side effects — it does not significantly inhibit serotonin and is sometimes added to an SSRI specifically to counteract SSRI-related sexual dysfunction. Lexapro, like other SSRIs, commonly causes sexual side effects including reduced libido and delayed orgasm. Patients for whom this is a significant concern may discuss this with their doctor when choosing between the two.
Yes, combining bupropion (Wellbutrin) with an SSRI like escitalopram (Lexapro) is an established clinical practice. The combination may provide additive antidepressant benefits and bupropion may help counteract the sexual side effects and weight gain sometimes associated with SSRIs. This combination should only be used under physician supervision.
Lexapro (escitalopram) is FDA-approved for generalized anxiety disorder and has strong evidence for anxiety treatment. Wellbutrin (bupropion) is not FDA-approved for anxiety and may in some patients worsen anxiety or agitation, particularly when starting treatment. For anxiety as a primary complaint, Lexapro is generally more commonly prescribed, but your doctor makes the final determination based on your full clinical picture.