Mirtazapine is an antidepressant often used for major depression. People also get it for anxiety or when sleep and appetite are a problem. It works differently from SSRIs: it boosts certain brain chemicals that lift mood and can make you sleepy. That sleep effect is useful for people who struggle to sleep, but it also explains some common side effects.
Typical starting dose is 15 mg at bedtime. Doctors may increase it up to 30–45 mg depending on response. Take it at night — it usually makes you drowsy. Common side effects include drowsiness, increased appetite, weight gain, dry mouth, and constipation. Some people feel dizzy at first or notice mild swelling.
Watch for less common but serious issues: sudden mood changes, suicidal thoughts (especially in people under 25), low white blood cell count (rare), or signs of serotonin syndrome if mixed with other serotonergic drugs. If you get a fever, severe rash, or trouble breathing, seek medical help immediately.
Avoid combining mirtazapine with MAO inhibitors and use caution with other antidepressants, tramadol, or St. John’s wort — these raise serotonin risk. Limit alcohol; it increases drowsiness and may worsen depression. If you’re pregnant, breastfeeding, or have liver or kidney problems, talk to your prescriber about risks and alternatives.
Stopping mirtazapine suddenly can cause withdrawal symptoms: anxiety, insomnia, flu-like feelings, or electric shock sensations. Your doctor should help you taper the dose over days or weeks rather than stopping cold turkey.
Practical day-to-day tips: take the pill at the same time each night, avoid driving until you know how it affects you, chew sugarless gum or sip water for dry mouth, and weigh yourself regularly if weight gain is a concern. Keep a simple journal of mood, sleep, and side effects for the first 4–8 weeks — that helps your prescriber decide whether to adjust the dose.
Buying meds online? Use only licensed pharmacies that require a prescription, show clear contact details, and have a privacy policy. If a site sells prescription drugs without asking for a prescription, steer clear. When you order, check packaging and expiry dates and report any suspicious pills to your pharmacist or doctor.
If your mood gets worse, you have new suicidal thoughts, or you experience severe side effects, contact your healthcare provider or local emergency services right away. With the right monitoring and a proper plan to start, adjust, and stop treatment, mirtazapine can be a useful tool for many people managing depression and sleep problems.
