Lexapro vs Wellbutrin: Comparing Two Popular Antidepressants

Lexapro and Wellbutrin are both antidepressants. That is where the similarity ends. They work through different neurotransmitters, affect different brain circuits, and feel meaningfully different in daily life. Choosing between them isn’t about finding the better antidepressant. It is about matching the mechanism to the clinical picture.

What This Page Covers

• How Lexapro and Wellbutrin work at the neurotransmitter level
• What each is FDA-approved for and what the approvals signal
• Efficacy comparison for depression
• How they compare on anxiety
• Side effect profiles: sexual dysfunction, weight, seizure risk
• Who each medication typically benefits most
• When prescribers combine them

How Each Medication Works

Lexapro (escitalopram) is a selective serotonin reuptake inhibitor (SSRI). It blocks the serotonin transporter, preventing serotonin from being reabsorbed into the presynaptic neuron after release. By increasing serotonin availability in the synaptic cleft, it affects mood regulation, sleep, appetite, and anxiety responses. Escitalopram is the most selective of the SSRIs in terms of receptor binding, with minimal CYP450 enzyme inhibition, making it one of the cleanest options for patients on multiple medications. FDA-approved for major depressive disorder and generalized anxiety disorder in adults.

Wellbutrin (bupropion) is an atypical antidepressant classified as a norepinephrine-dopamine reuptake inhibitor (NDRI). It blocks the reuptake of dopamine and norepinephrine while having minimal effect on serotonin. Dopamine influences motivation, reward, and pleasure. Norepinephrine influences alertness, energy, and focus. Wellbutrin’s distinct mechanism explains its more activating or energizing effect compared to SSRIs, making it particularly useful for patients whose depression presents as fatigue, apathy, and loss of motivation. FDA-approved for major depressive disorder, seasonal affective disorder, and smoking cessation.

How Their Efficacy Compares

Both medications perform similarly for depression overall. Clinical trials and meta-analyses show comparable depression response rates of 60 to 70% for Lexapro and Wellbutrin in major depressive disorder. A study with nearly 800 participants comparing escitalopram to bupropion found no major difference in antidepressant efficacy.

A 2018 Lancet network meta-analysis of 522 trials found that escitalopram showed the best balance of efficacy and acceptability among SSRIs, while the 2025 CANMAT guidelines list bupropion among the most effective medications for MDD. The similarity in depression efficacy means side effect profile and specific symptom pattern, not raw effectiveness, should guide the choice.

How They Differ for Anxiety

This is where the divergence matters most.

Lexapro has FDA approval for generalized anxiety disorder and is a first-line treatment for most anxiety disorders. The serotonin-based mechanism calms the fear circuitry that drives anxiety.

Wellbutrin is not FDA-approved for anxiety. A meta-analysis of 10 double-blind randomized studies found that SSRIs outperformed bupropion for patients with anxious depression, with a 6% difference in response rates favoring SSRIs. Wellbutrin’s activating effect can increase anxiety, particularly at higher doses. It is not the appropriate starting choice when anxiety is a significant part of the clinical picture.

Side Effect Profiles: What Actually Affects Adherence

Sexual Side Effects

Lexapro, like all SSRIs, is associated with substantial rates of sexual dysfunction when assessed directly rather than relying on spontaneous reporting. Studies using systematic assessment find sexual dysfunction rates of 60 to 80% across the SSRI class, including decreased libido, difficulty with arousal, and delayed or absent orgasm.

Wellbutrin is known for having very low rates of sexual side effects because it does not act on serotonin, and is sometimes prescribed alongside an SSRI specifically to counteract SSRI-induced sexual dysfunction. A 2010 meta-analysis found sexual dysfunction occurred significantly less frequently with bupropion than with SSRI-class drugs.

Sexual side effects are among the most common reasons patients stop antidepressants without telling their prescriber. Having this conversation before starting allows for an informed choice.

Weight

Lexapro can cause modest weight gain, particularly with long-term use. A large study analyzing data from over 183,000 people found that Wellbutrin recipients lost an average of 0.5 lbs and were 15% less likely to gain significant weight, while escitalopram was linked to a 10 to 15% increased risk of significant weight gain. For patients managing weight as part of their overall health, this difference is worth discussing explicitly.

Seizure Risk

Wellbutrin carries a dose-dependent risk of seizures. This risk is low at standard doses but meaningful at doses above 450 mg per day and in patients with predisposing factors. Wellbutrin is contraindicated in patients with seizure disorders, bulimia nervosa, or anorexia nervosa due to electrolyte imbalances that lower seizure threshold. Lexapro has no seizure risk under normal clinical use.

Who Each Medication Typically Benefits Most

Lexapro tends to fit best when:

• Anxiety is prominent alongside or driving depression
• Sleep disturbance is a significant symptom
• Minimizing drug interactions is a priority (cleanest CYP450 profile in the SSRI class)
• First-time antidepressant users who want the most-studied SSRI profile

Wellbutrin tends to fit best when:

• Depression features low energy, fatigue, poor motivation, and anhedonia without prominent anxiety
• Sexual side effects on a prior SSRI led to discontinuation
• Weight gain on prior antidepressants is a concern
• Smoking cessation is also a goal

The prescriber’s assessment of your specific clinical picture guides this decision, not the medication with the most attractive general profile.

When Both Are Prescribed Together

Combining escitalopram and bupropion is a recognized clinical strategy. Wellbutrin can be useful in addressing symptoms of low energy and poor concentration that SSRIs like Lexapro often do not treat, while Lexapro works well at easing anxiety symptoms that co-occur with depression. The combination also addresses SSRI-induced sexual dysfunction while maintaining the anxiolytic benefit.

Any combination requires monitoring for drug interactions. Wellbutrin is a CYP2D6 inhibitor and can raise plasma levels of some other medications metabolized by that enzyme.

The Role of Daily Monitoring

Both medications require 4 to 6 weeks at a therapeutic dose before full effect can be assessed. In that window, catching side effects early before they drive discontinuation matters as much as waiting for the medication to work.

“The first weeks on an antidepressant are where the most important clinical information is generated,” says Daniel Montville, MD, Psychiatrist, of the SiggyMD clinical team. “Which side effects are tolerable, whether sleep is improving, whether there is an early signal of response. Without that data, the first follow-up appointment is often the first time anything gets addressed.”

About SiggyMD

SiggyMD provides clinician-reviewed psychiatric care with daily check-ins and licensed prescriber oversight. Start your anonymous intake with SiggyMD to connect with a licensed prescriber who will review your full clinical picture and explain the options in context. For more detail on how SSRIs compare to each other, read our SSRI Medications Compared guide.

What Members Are Saying

BP

B.P., 31

Depression

“I had been on Lexapro for two years and didn’t realize how much the sexual side effects were affecting my relationship until a prescriber asked directly. We added a low dose of Wellbutrin and it was a different experience. I wish someone had surfaced that option earlier.”

KM

K.M., 26

Generalized Anxiety and Depression

“My anxiety is as much a problem as the depression. My prescriber started me on Lexapro for that reason. The distinction made sense once it was explained. Anxiety needs serotonin. I’d been trying to self-prescribe the wrong mechanism.”

Member stories reflect real experiences. Names and identifying details have been changed to protect privacy. Results vary. SiggyMD is currently invite-only.

Sources

1. Cipriani A, et al. Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with MDD: a network meta-analysis. The Lancet. 2018;391(10128):1357-1366.

2. Lam RW, et al. CANMAT 2023 Update on Clinical Guidelines for Management of Major Depressive Disorder. The Canadian Journal of Psychiatry. 2024;69(9):641-687.

3. Papakostas GI, et al. Efficacy of Bupropion and SSRIs in the Treatment of MDD With High Levels of Anxiety. Journal of Clinical Psychiatry. 2008;69(8):1287-1292.

4. Rizvi SJ, Kennedy SH. Managing SSRI-Induced Sexual Dysfunction. Journal of Psychiatry and Neuroscience. 2013;38(5).

5. Hamzehpour R, et al. Comparison of Escitalopram and Bupropion in treatment of depression in heart failure patients. Annals of Medicine and Surgery. 2024;86(11):6546-6554.

6. Mayo Clinic. Antidepressants: Selecting one that’s right for you. Accessed June 2026.

7. Oldak SE, Maristany A. Bupropion and Anxiety: A Brief Review. Human Psychopharmacology. 2025;40(5).

Reviewed by Daniel Montville, MD, Psychiatrist | Last updated June 2026