Understanding Bupropion: What Drug Class Is Bupropion?

October 10, 2025 •

4 min read

In 2023, bupropion was the seventeenth most commonly prescribed medication in the United States, with over 30 million prescriptions [1.2.3]. So, what drug class is bupropion? It is an atypical antidepressant belonging to the norepinephrine-dopamine reuptake inhibitor (NDRI) class [1.2.3].

Quick Summary

Bupropion is an atypical antidepressant classified as a norepinephrine-dopamine reuptake inhibitor (NDRI). It treats depression and helps with smoking cessation by affecting brain chemistry differently than SSRIs.

Key Points

Drug Class: Bupropion is classified as a norepinephrine-dopamine reuptake inhibitor (NDRI), which is a type of atypical antidepressant [1.2.3].
Mechanism: It primarily works by increasing the levels of norepinephrine and dopamine in the brain, with little effect on serotonin [1.3.2].
Approved Uses: The FDA has approved bupropion for treating Major Depressive Disorder (MDD), Seasonal Affective Disorder (SAD), and for smoking cessation [1.4.1].
Side Effect Profile: Unlike many SSRIs, bupropion has a lower risk of causing sexual side effects and weight gain; in fact, it is often associated with weight loss [1.4.2, 1.13.2].
Primary Risk: The most significant risk associated with bupropion is a dose-dependent increased risk of seizures, making it unsuitable for people with seizure or eating disorders [1.8.2, 1.8.3].
Brand Names: Bupropion is commonly marketed under brand names including Wellbutrin, Wellbutrin SR, Wellbutrin XL, and Zyban [1.9.1].
Off-Label Applications: It is frequently prescribed off-label for conditions like ADHD and to counteract sexual dysfunction caused by other antidepressants [1.5.2, 1.4.2].

Introduction to Bupropion

Bupropion is a widely prescribed medication known by brand names such as Wellbutrin, Aplenzin, and Zyban [1.9.1, 1.9.3]. First approved by the FDA in 1985, it has become a cornerstone treatment for several conditions [1.2.3, 1.4.1]. Unlike many other antidepressants, bupropion holds a unique position due to its distinct mechanism of action and side effect profile. It is available in immediate-release (IR), sustained-release (SR), and extended-release (XL) formulations, which allow for different dosing schedules [1.4.1].

The Atypical Antidepressant: What Drug Class is Bupropion?

Bupropion is classified as a norepinephrine-dopamine reuptake inhibitor (NDRI) [1.2.3]. This categorization makes it an "atypical" antidepressant because its mechanism is different from the more common selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) [1.14.2].

Mechanism of Action

The exact mechanism of bupropion is not fully understood, but it is known to work by weakly inhibiting the reuptake of two key neurotransmitters in the brain: norepinephrine and dopamine [1.3.2]. By blocking their reuptake, bupropion increases the levels of these chemicals available in the brain, which helps to regulate mood, motivation, and focus [1.3.2, 1.5.1]. It has a minimal effect on serotonin, which is the primary target of SSRIs [1.7.1]. Additionally, bupropion acts as a non-competitive antagonist of nicotinic acetylcholine receptors, a property believed to contribute to its effectiveness as a smoking cessation aid [1.3.2].

FDA-Approved and Off-Label Uses

Bupropion is officially approved by the U.S. Food and Drug Administration (FDA) for specific conditions, but it is also frequently used for other purposes.

FDA-Approved Indications

Major Depressive Disorder (MDD): Bupropion is used for the treatment of MDD in adults [1.4.1, 1.4.3]. Its stimulating properties can be particularly helpful for individuals experiencing depression with symptoms of fatigue and low energy.
Seasonal Affective Disorder (SAD): The extended-release formulation (Wellbutrin XL) is indicated for the prevention of depressive episodes in patients with SAD, a type of depression that occurs seasonally, usually in the fall and winter [1.4.1, 1.4.3].
Smoking Cessation: Under the brand name Zyban, bupropion is approved as an aid to help people stop smoking [1.4.1, 1.2.1]. It is thought to reduce nicotine cravings and withdrawal symptoms.

Common Off-Label Uses

Clinicians may also prescribe bupropion for conditions it is not officially approved to treat. This is known as "off-label" use. Common off-label uses include:

Attention-Deficit/Hyperactivity Disorder (ADHD): Due to its effects on dopamine and norepinephrine, bupropion is sometimes used as a non-stimulant option for treating ADHD, especially in adults who may not tolerate stimulants well or have co-occurring depression [1.5.1, 1.5.2].
Bipolar Disorder: It may be used to treat depressive episodes associated with bipolar disorder, though caution is required as antidepressants can risk inducing a manic episode [1.4.2].
Antidepressant-Induced Sexual Dysfunction: Because bupropion does not typically cause the sexual side effects associated with SSRIs, it is sometimes added to a treatment regimen or used as an alternative to counteract this issue [1.4.2].
Obesity: Bupropion can cause weight loss as a side effect and is a component of the weight-loss medication Contrave (naltrexone/bupropion) [1.13.2].

Bupropion vs. Other Antidepressants: A Comparison

Bupropion's unique profile sets it apart from SSRIs and SNRIs. This difference is most notable in its side effects.


Feature	Bupropion (NDRI)	SSRIs (e.g., Sertraline)	SNRIs (e.g., Venlafaxine)
Mechanism	Inhibits reuptake of norepinephrine and dopamine [1.3.2]	Inhibits reuptake of serotonin [1.7.1]	Inhibits reuptake of serotonin and norepinephrine [1.7.1]
Sexual Side Effects	Low risk; sometimes used to treat them [1.4.2]	Common	Common
Effect on Weight	Often associated with weight loss or is weight-neutral [1.13.2]	Can cause weight gain [1.13.2]	Can cause weight gain or loss
Common Side Effects	Insomnia, dry mouth, headache, agitation [1.6.2, 1.4.1]	Nausea, drowsiness, sexual dysfunction	Nausea, dizziness, sweating
Seizure Risk	Increased, dose-dependent risk [1.8.3, 1.6.2]	Low risk	Low risk

Potential Side Effects and Safety Warnings

While many tolerate bupropion well, it has potential side effects and important safety warnings.

Common Side Effects

Many common side effects are mild and may decrease over the first few weeks of treatment [1.6.2]. They include:

Insomnia or trouble sleeping [1.6.2]
Headache [1.6.2]
Dry mouth [1.6.2]
Nausea [1.6.2]
Dizziness [1.6.2]
Agitation or anxiety [1.4.1]
Constipation [1.6.2]

Serious Risks and Contraindications

Seizure Risk: Bupropion carries a dose-dependent risk of seizures. The risk is about 0.4% at doses up to 450 mg/day but increases significantly at higher doses [1.8.3, 1.10.1]. It is contraindicated in individuals with a seizure disorder or a history of anorexia or bulimia, as these conditions increase seizure risk [1.8.2].
Suicidal Thoughts and Behaviors: Like all antidepressants, bupropion has an FDA black box warning about an increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults [1.6.2, 1.8.2].
Hypertension: Bupropion can cause an increase in blood pressure. Blood pressure should be monitored before and during treatment [1.8.2].
Alcohol Interaction: Consuming alcohol while taking bupropion should be avoided or limited, as it can lower the seizure threshold and increase the risk of neuropsychiatric side effects [1.12.2, 1.12.3].
Contraindications: Do not take bupropion if you have a seizure disorder, an eating disorder like anorexia or bulimia, or are abruptly discontinuing alcohol or sedatives [1.8.2]. It is also contraindicated for patients taking MAOIs [1.8.2].

Conclusion

In summary, bupropion is an atypical antidepressant belonging to the NDRI drug class [1.2.3]. Its unique mechanism of action, which primarily involves increasing norepinephrine and dopamine levels, distinguishes it from SSRIs and SNRIs [1.3.2]. This makes it an effective treatment for major depressive disorder, seasonal affective disorder, and smoking cessation, with a side effect profile notable for its low risk of sexual dysfunction and potential for weight loss [1.4.1, 1.4.2, 1.13.2]. However, it requires careful medical supervision due to its dose-dependent seizure risk and other important safety considerations [1.8.3].

For further reading, you can visit the National Alliance on Mental Illness (NAMI) page on Bupropion.

Frequently Asked Questions

Some initial improvements in energy and sleep may be noticed within 1-2 weeks, but the full antidepressant effects can take 4 to 6 weeks or longer to become apparent [1.11.1, 1.11.3].

It is generally recommended to avoid or limit alcohol consumption. The combination can lower your seizure threshold and may increase the risk of side effects like dizziness and confusion [1.12.2, 1.12.3].

No, bupropion is not a controlled substance in the United States. It is a prescription-only medication but does not fall under the Controlled Substances Act [1.16.1, 1.16.3].

Bupropion is more likely to cause weight loss than weight gain, which is a key difference from many other antidepressants. It is an active ingredient in the weight-loss medication Contrave [1.13.2].

No, bupropion is not an SSRI. It is a norepinephrine-dopamine reuptake inhibitor (NDRI) and works on different neurotransmitters than SSRIs, which primarily affect serotonin [1.7.1, 1.2.3].

Bupropion's use for anxiety is considered off-label. While it can worsen anxiety in some individuals, particularly at first, it may be effective for others, especially if anxiety co-occurs with depression characterized by low energy [1.14.1, 1.14.3].

Abruptly stopping bupropion is not recommended as it can lead to withdrawal symptoms such as irritability, anxiety, insomnia, and headaches. A doctor will typically create a tapering schedule to discontinue the medication safely [1.15.1, 1.15.3].