How long do the side effects of mirtazapine last?

The duration for side effects of mirtazapine to subside varies from person to person and depends on the type of side effect, dosage, and individual metabolic capacity. Most short-term side effects typically ease within 1–2 weeks, while some may last longer and require targeted adjustments. A detailed analysis is as follows:

Common side effects such as drowsiness, dry mouth, and dizziness that occur early in treatment are mostly due to the body not yet adapting to the medication. These side effects are usually mild and tend to diminish significantly or disappear entirely within 1–2 weeks as the body gradually develops tolerance with continued use. No special intervention is needed—adequate rest is sufficient. A minority of individuals may experience longer-lasting side effects such as weight changes or mood fluctuations, which could take several weeks to months to stabilize. If side effects significantly affect daily life, dosage adjustments should be made under a doctor’s guidance rather than discontinuing the medication independently. Abruptly stopping the drug may lead to symptom relapse, thereby increasing physical burden.

During mirtazapine treatment, it is important to take the medication at a consistent time each day to maintain stable blood concentration. Additionally, maintaining a light diet and regular sleep schedule can help the body adapt to the drug. Keep a record of when side effects occur and how they change over time, and communicate regularly with your doctor to allow timely adjustments to the treatment plan and ensure safe medication use.