Can Mirtazapine Cause Nausea?
Mirtazapine is actually associated with LOWER rates of nausea compared to other antidepressants, and is even being studied as a treatment for nausea in other conditions.
Adverse Event Profile
According to the FDA drug label, the most common side effects of mirtazapine include sleepiness, increased appetite, weight gain, and dizziness 1. Notably, nausea is NOT listed among the most common adverse effects of mirtazapine 1.
Comparative Evidence from Guidelines
The American College of Physicians guidelines on second-generation antidepressants provide important context: while nausea and vomiting were the most common reasons for discontinuation across antidepressant trials generally, mirtazapine specifically had LOWER rates of gastrointestinal side effects compared to SSRIs 2. The guideline notes that sertraline had higher rates of diarrhea than mirtazapine, and venlafaxine had higher incidence of nausea and vomiting than other SSRIs 2.
Clinical Research Supporting Anti-Nausea Properties
Emerging evidence actually suggests mirtazapine may be therapeutic for nausea:
- A 2025 case series demonstrated successful use of mirtazapine 15 mg for severe nausea and vomiting during pregnancy when standard antiemetics failed, with rapid symptom improvement 3
- A 2026 systematic review found mirtazapine improved IBS symptoms including gastrointestinal complaints 4
- A 1995 safety review noted that typical SSRI adverse events such as nausea, vomiting, and diarrhea were registered LESS frequently in mirtazapine-treated patients than in placebo-treated patients 5
Important Caveats
While mirtazapine rarely causes nausea as a direct side effect, be aware that:
- Serotonin syndrome (which includes nausea as a symptom) can occur when mirtazapine is combined with other serotonergic drugs 1
- Discontinuation syndrome upon abrupt cessation can include nausea and vomiting 1
Clinical Bottom Line
If a patient reports nausea while taking mirtazapine, consider alternative explanations (underlying depression, drug interactions, discontinuation effects, or concurrent illness) rather than attributing it to mirtazapine itself. Mirtazapine's pharmacologic profile (blocking 5-HT3 receptors) actually provides anti-nausea effects, making it one of the better-tolerated antidepressants for patients concerned about gastrointestinal side effects.