What Is Mirtazapine? Uses, Dosage, and What You Need to Know in 2026

Mirtazapine (brand name: Remeron) is a prescription antidepressant that has been in use since 1996. It belongs to a class called tetracyclic antidepressants and works differently from the more commonly known SSRIs. Here's everything you need to know about it in 2026.

What Is Mirtazapine?

Mirtazapine is an atypical tetracyclic antidepressant, sometimes called a NaSSA (Noradrenergic and Specific Serotonergic Antidepressant). It was FDA-approved in 1996 to treat major depressive disorder (MDD) in adults. Today it is available almost entirely as a generic, with brand-name Remeron still available but rarely used due to cost.

Key facts:

Generic name: Mirtazapine

Brand names: Remeron, Remeron SolTab

Drug class: Tetracyclic antidepressant (NaSSA)

Controlled substance: No — not a scheduled substance

FDA-approved: 1996 for MDD in adults

What Is Mirtazapine Used For?

FDA-approved use:

Major depressive disorder (MDD) in adults

Common off-label uses:

Insomnia (low-dose, usually 7.5-15 mg at bedtime)

Generalized anxiety disorder (GAD)

Post-traumatic stress disorder (PTSD)

Panic disorder and social anxiety disorder

Appetite stimulation and weight gain (cancer, HIV, eating disorders)

Nausea (antiemetic effect via 5-HT3 blockade)

Migraine prevention

Mirtazapine Dosage Forms and Strengths

Mirtazapine is available in two forms:

Regular oral tablets: 7.5 mg, 15 mg, 30 mg, 45 mg

Orally disintegrating tablets (ODT/SolTab): 15 mg, 30 mg, 45 mg (dissolves on the tongue — useful for those who have difficulty swallowing pills)

Mirtazapine Dosing: How Much and When?

For MDD, the typical starting dose is 15 mg taken once daily at bedtime. The dose may be increased by your prescriber every 1-2 weeks:

Starting dose: 15 mg/day at bedtime

Usual therapeutic range: 15-45 mg/day

Maximum dose: 45 mg/day (some off-label use at 60 mg)

For insomnia (off-label): Often 7.5-15 mg at bedtime (more sedating at lower doses)

Elderly patients: Start at 7.5 mg/day; slower titration recommended

How to Take Mirtazapine

Take mirtazapine once daily, usually at bedtime, to reduce daytime sedation

Can be taken with or without food — food does not affect absorption

For ODT form: Place on tongue and let dissolve — do not chew or split

Mirtazapine has a half-life of 20-40 hours, allowing once-daily dosing

It may take 1-4 weeks to feel the antidepressant effect (sleep improvements may come sooner)

Who Should Not Take Mirtazapine?

Mirtazapine is contraindicated in patients who:

Are taking or have taken MAO inhibitors in the past 14 days (includes phenelzine, tranylcypromine, linezolid, IV methylene blue)

Have a known hypersensitivity to mirtazapine

Use with caution in patients with seizure history, bipolar disorder, significant liver or kidney disease, or cardiovascular conditions.

How Does Mirtazapine Compare to SSRIs?

A major 2018 analysis of 21 antidepressants found mirtazapine to be in the more effective group. It also tends to work faster — some patients notice effects within 1-2 weeks vs. 4-6 weeks for many SSRIs. Its key advantages over SSRIs include less sexual dysfunction, better sleep, and appetite stimulation. Its disadvantages include greater sedation and weight gain.

Want to understand the science? Read: How does mirtazapine work? Mechanism of action explained.

If you need help finding mirtazapine at a local pharmacy, medfinder can search nearby pharmacies for stock and text you results.