Can Bupropion Mess With Hormones? A Pharmacological Review

October 10, 2025 •

4 min read

In 2023, bupropion was the 17th most commonly prescribed medication in the United States, with over 30 million prescriptions [1.9.5]. A common question among users is, can bupropion mess with hormones? The answer is complex, with effects varying across different hormonal systems.

Quick Summary

Bupropion's impact on hormones is multifaceted. It primarily acts on dopamine and norepinephrine, which can indirectly influence sex hormones, stress hormones like cortisol, and prolactin, though its effects are often different from other antidepressants.

Key Points

Mechanism of Action: Bupropion is an NDRI, increasing dopamine and norepinephrine, unlike SSRIs which affect serotonin [1.8.2].
Testosterone & Libido: Bupropion is less likely to cause sexual dysfunction and may increase testosterone and libido in some individuals [1.4.1, 1.4.4].
Cortisol Effects: The impact on the stress hormone cortisol is variable and may be linked to whether a person responds to the drug's antidepressant effects [1.3.2, 1.3.4].
Female Hormones: In animal studies, bupropion has been shown to affect reproductive hormones like LH and AMH, with non-significant changes to estradiol [1.2.1].
Prolactin Levels: Evidence on bupropion's effect on prolactin is mixed, with some studies showing a decrease and others showing no effect [1.7.1, 1.7.3].
Thyroid Interaction: There are no known significant interactions between bupropion and common thyroid medications [1.6.4, 1.6.5].
Consult a Professional: Individual hormonal responses to bupropion vary, making it essential to discuss concerns with a healthcare provider.

Understanding Bupropion and Its Mechanism

Bupropion, sold under brand names like Wellbutrin®, is an atypical antidepressant used to treat major depressive disorder and seasonal affective disorder, and to help with smoking cessation [1.8.3, 1.9.5]. Unlike many other antidepressants that primarily act on serotonin, bupropion is a norepinephrine-dopamine reuptake inhibitor (NDRI) [1.8.2]. This means it increases the levels of two key neurotransmitters in the brain: norepinephrine and dopamine [1.2.4]. This unique mechanism is responsible for its distinct side effect profile, especially concerning hormonal and sexual health [1.8.4].

Bupropion's Influence on Sex Hormones: Testosterone and Estrogen

One of the most discussed aspects of bupropion is its effect on libido and sexual function, which is closely tied to sex hormones.

Testosterone

Unlike Selective Serotonin Reuptake Inhibitors (SSRIs), which can sometimes contribute to testosterone loss, bupropion is often considered a better alternative for patients with low testosterone [1.4.3]. Some research suggests a potential link between bupropion and increased testosterone levels, which may lead to heightened arousal [1.4.1, 1.4.4]. One study on male rats found that bupropion treatment significantly increased testosterone levels [1.2.2]. For individuals experiencing sexual dysfunction caused by SSRIs, bupropion has been studied as an antidote, showing an increase in self-reported desire and frequency of sexual activity [1.4.2]. However, research remains inconclusive, and individual responses can vary significantly [1.4.1].

Estrogen and Female Hormones

A study on female rats found that chronic bupropion exposure led to a decrease in serum anti-Müllerian hormone (AMH) and luteinizing hormone (LH) levels, and a non-significant increase in estradiol (a form of estrogen) [1.2.1]. The study concluded that long-term use could potentially disrupt reproductive functions [1.2.1]. For postmenopausal women, some may notice an increased sex drive while taking the medication due to its effects on dopamine [1.2.3]. Bupropion has also been studied for improving sexual function in female breast cancer survivors on hormonal therapy, showing positive results [1.2.5].

The Stress Hormone: Cortisol

The relationship between bupropion and cortisol, a primary stress hormone regulated by the hypothalamic-pituitary-adrenal (HPA) axis, is complex. Research indicates that its effects can differ based on timing and individual response to the medication.

Some studies suggest that morning administration of bupropion might elevate cortisol levels early in the day, potentially increasing alertness, without affecting evening cortisol [1.3.1]. Other research found that in patients with major depression, bupropion significantly increased nocturnal urinary free cortisol, but only in those who did not respond to the antidepressant effects of the drug; responders showed no such change [1.3.2, 1.3.4]. This suggests the interaction is not straightforward and may be linked to the drug's therapeutic efficacy.

Bupropion's Effect on Other Hormones

Prolactin

The evidence regarding bupropion's effect on prolactin is mixed. Prolactin is a hormone primarily associated with milk production, but it also affects sexual function. Some antipsychotics and antidepressants are known to raise prolactin levels, which can cause issues like decreased libido or menstrual irregularities. Due to its dopamine-mimetic properties, bupropion has been theorized to lower prolactin levels, as dopamine naturally inhibits prolactin secretion [1.7.1, 1.7.2].

However, studies have produced conflicting results. One early study found bupropion failed to suppress prolactin in healthy volunteers [1.7.3]. A case study also reported that bupropion did not lower elevated prolactin levels in a patient with a pituitary microadenoma [1.7.4]. Conversely, there is a rare case report of hyperprolactinemia developing after bupropion was added to another antidepressant treatment [1.7.5]. Generally, the effect is considered modest and not clinically significant for most patients [1.7.1].

Thyroid Hormones

There is little evidence to suggest that bupropion directly interferes with thyroid hormone levels or medications. Searches for interactions between bupropion and common thyroid medications like Synthroid (levothyroxine), Armour Thyroid, and NP Thyroid show no known significant interactions [1.6.1, 1.6.2, 1.6.4, 1.6.5]. While bupropion is sometimes tried by patients with Hashimoto's thyroiditis, it is not a standard treatment, and patients should always consult their doctor before making any changes [1.6.6].

Comparison of Bupropion's Hormonal Effects


Hormone	Reported Effect of Bupropion	Evidence Summary
Testosterone	May increase levels; often neutral or positive effect on libido.	Some animal studies show increased levels [1.2.2]. Used as an antidote for SSRI-induced sexual dysfunction [1.4.2]. Research is not definitive [1.4.1].
Estrogen	May cause a slight, non-significant increase in estradiol.	Animal studies suggest potential changes in reproductive hormones like LH and AMH, with minor impact on estradiol [1.2.1].
Cortisol	Variable; may increase levels, particularly in non-responders.	Effects appear linked to antidepressant response; some studies show a temporary increase after morning doses [1.3.1, 1.3.2].
Prolactin	Mixed results; theoretically may lower levels, but evidence is inconsistent.	Some studies suggest a lowering effect, while others show no significant change or rare cases of elevation [1.7.1, 1.7.3, 1.7.5].
Thyroid Hormones	No significant interaction reported.	No known interactions with common thyroid medications [1.6.1, 1.6.4].

Conclusion

So, can bupropion mess with hormones? Yes, it can, but its profile is notably different from many other antidepressants. Its primary action on dopamine and norepinephrine can lead to indirect effects on sex hormones, often resulting in a neutral or even positive impact on libido, unlike the suppressive effects sometimes seen with SSRIs [1.2.3, 1.4.3]. The influence on cortisol is variable and may be tied to the drug's effectiveness for an individual [1.3.4]. Effects on prolactin and thyroid hormones appear to be minimal or inconsistent based on current evidence [1.7.1, 1.6.4]. As with any medication, individual responses can vary, and it is crucial to discuss any hormonal concerns with a healthcare provider.

Authoritative Link: For more detailed information on Bupropion, its uses, and side effects, visit the National Library of Medicine's resource page: https://www.ncbi.nlm.nih.gov/books/NBK470212/

Frequently Asked Questions

Some studies, primarily in animals, have shown that bupropion can increase testosterone levels [1.2.2]. It is often considered a favorable option for patients concerned about the low testosterone associated with other antidepressants, though human studies are not definitive [1.4.1, 1.4.3].

Animal studies suggest chronic bupropion use can affect female reproductive hormones, including luteinizing hormone (LH) and anti-Müllerian hormone (AMH), and may cause a slight increase in estradiol [1.2.1]. While rare, menstrual irregularities have been reported, so any changes should be discussed with a doctor.

Bupropion's effect on cortisol can be complex. Some research indicates it may cause a temporary increase after a morning dose [1.3.1]. Other studies found it raised cortisol levels only in patients who did not respond to its antidepressant effects [1.3.2, 1.3.4].

Bupropion is often preferred when sexual side effects are a concern because it works on dopamine and norepinephrine, not serotonin [1.8.4]. It is less likely to cause low libido and is sometimes prescribed to counteract sexual dysfunction caused by SSRIs [1.4.2].

While not a commonly reported side effect, any medication that influences hormones could potentially affect the skin. Since bupropion can have varied effects on hormones like testosterone and cortisol, it's theoretically possible, but not a widely documented issue. Consult a dermatologist for any skin concerns.

Current information indicates there are no known significant drug interactions between bupropion and common thyroid medications like levothyroxine (Synthroid) or Armour Thyroid [1.6.2, 1.6.4, 1.6.5].

This is very rare. Because bupropion can increase dopamine activity, it is more likely to lower prolactin levels [1.7.1]. However, there is at least one case report of hyperprolactinemia occurring when bupropion was added to another antidepressant [1.7.5]. The evidence overall is inconsistent [1.7.3].