Wellbutrin vs Zoloft
How bupropion and sertraline compare, two common antidepressants that work differently.
How they're similar
Bupropion and sertraline are both common antidepressants, and despite working differently they share several features.
- Both treat depression.
- Both are effective.
- They follow the same timeline. Early side effects can show in the first week or two, while the fuller effect on mood usually takes four to six weeks.
- Both carry the antidepressant boxed warning about a possible increase in suicidal thoughts in people under 25, especially early in treatment.
- Both have been available as inexpensive generics for years.
How they differ
The biggest difference is how they work, and that shapes most of the rest. The table below sums up the core points, with more detail underneath.
| Bupropion (Wellbutrin) | Sertraline (Zoloft) | |
|---|---|---|
| Drug class | NDRI, a norepinephrine-dopamine reuptake inhibitor | SSRI, a selective serotonin reuptake inhibitor |
| How it works | Acts on norepinephrine and dopamine | Acts on serotonin |
| Effect on anxiety | Not a first choice for anxiety, can make it worse for some people | Strongly effective and broadly approved for anxiety conditions |
| Sexual side effects | Rare, and bupropion is sometimes added to an SSRI to counter them | Common |
| Effect on weight | Weight-neutral or linked with mild weight loss | Roughly weight-neutral, with modest gain possible long-term for some people |
| Energy and activation | Activating, can help with low energy but can cause insomnia or jitteriness | More neutral |
| Seizure risk | Dose-related seizure risk, not used with a seizure disorder or a current or past eating disorder | Does not carry that risk |
The starting point is mechanism. Bupropion is an NDRI, a norepinephrine-dopamine reuptake inhibitor, so it works on norepinephrine and dopamine. Sertraline is an SSRI, a selective serotonin reuptake inhibitor, so it works on serotonin.
That difference drives anxiety. Sertraline is strongly effective and broadly approved for anxiety conditions, including panic disorder, post-traumatic stress disorder, social anxiety disorder, and obsessive-compulsive disorder. Bupropion is not a first choice for anxiety, and because it is activating it can make anxiety worse for some people. So for depression that comes with anxiety, sertraline is usually preferred.
Sexual side effects also differ. Sertraline commonly causes them. Bupropion rarely does, and it is sometimes added to an SSRI to counter them.
On weight, sertraline is roughly weight-neutral, with modest gain possible long-term for some people. Bupropion is weight-neutral or linked with mild weight loss.
Energy is another difference. Bupropion is activating and can help with low energy, but it can also cause insomnia or jitteriness. Sertraline is more neutral.
There is one safety difference that stands out. Bupropion has a dose-related seizure risk, and it should not be used in people with a seizure disorder or with a current or past eating disorder. Sertraline does not carry that risk.
On stomach effects, sertraline is more associated with loose stools and diarrhea. And bupropion has one extra use worth noting: it also helps people quit smoking.
Side effects compared
The two medications have fairly different side effect profiles, which follows from working differently. Sertraline more often causes sexual side effects, loose stools and diarrhea, and other stomach effects. Bupropion more often causes insomnia, jitteriness, and dry mouth, and it carries the dose-related seizure risk noted above.
With both, side effects tend to arrive before the benefit. If a side effect is severe, or it is not improving after a few weeks, that is a conversation to have with a prescriber rather than a reason to stop on your own.
Sleep, weight, and sexual effects
This is where the two differ most.
For sleep, bupropion is activating and more likely to cause insomnia, while sertraline is more neutral. For weight, sertraline is roughly weight-neutral with modest gain possible long-term for some people, while bupropion is weight-neutral or linked with mild weight loss. For sexual effects, sertraline commonly causes lower sex drive, delayed orgasm, and arousal difficulties, while bupropion rarely does. These effects are worth raising with a prescriber, because there are real options, including a dose change, a switch, or adding bupropion to an SSRI.
Why a clinician might choose one over the other
Because the two work differently, the choice often comes down to the symptom picture.
A clinician might choose sertraline for depression that comes with anxiety, or for panic disorder, PTSD, or OCD, where sertraline is formally approved.
A clinician might choose bupropion for depression with fatigue or low energy, or for someone who wants to avoid sexual side effects or weight gain, or who also wants to quit smoking. Bupropion is not a good fit when anxiety is prominent, or when there is a seizure disorder or a current or past eating disorder. The two are also sometimes prescribed together, with bupropion added to sertraline to broaden the effect or to offset sexual side effects.
The bottom line
Bupropion and sertraline are two different tools. Neither is clearly better. The right choice depends on the symptom picture and which side effects a person most wants to avoid, and it is decided with a prescriber. It is also common to try one and switch to the other, or to use them together, if that is the better fit. A first medication that does not suit someone is a normal step in treatment, not a failure.
Sources
This guide draws on current prescribing information and public health references. It is reviewed for clinical accuracy and updated as guidance changes.
- U.S. Food and Drug Administration. Bupropion prescribing information.
- U.S. Food and Drug Administration. Sertraline prescribing information.
- MedlinePlus, U.S. National Library of Medicine.
- National Institute of Mental Health. Mental health medications.
Managing a medication needs a prescriber
Any psychiatric medication has to be started and adjusted by a clinician who can follow you over time. If you don't have a prescriber, our guides section explains the options, including in-person care and telepsychiatry, and how to choose between them.
This guide is for general education. It is not medical advice and is not a substitute for evaluation, diagnosis, or treatment by a qualified clinician. Never start, stop, or change a medication without talking to your prescriber. If you are in crisis or thinking about harming yourself, call or text 988 in the U.S. to reach the Suicide and Crisis Lifeline.