Remeron (Mirtazapine)
Remeron is the original brand of mirtazapine, an atypical antidepressant of the NaSSA class. It is sedating and appetite-stimulating at low doses, with notably fewer sexual side effects than SSRIs, and is widely used in depression with insomnia, weight loss or anxiety.
- Active ingredients
- Mirtazapine
- Manufacturer
- Organon / Merck
- Dosage forms
- tablet
- Available dosages
- 7.5mg, 15mg, 30mg, 45mg
- Category
- Anti-Depressants
What is it?
Remeron is the brand name under which Organon (now part of Merck) markets mirtazapine; FDA-approved in 1996 it brought a distinctive antidepressant to market that complements SSRIs in patients where sleep, appetite or sexual side-effect profile drives selection. Authorised generic mirtazapine has been widely available since 2004 and dominates current prescribing — most clinical use today is on the generic. The brand survives by recognition and prescriber preference.
Active ingredients
Each Remeron tablet contains 7.5mg, 15mg, 30mg or 45mg of mirtazapine. The active substance is identical between branded Remeron and authorised generic mirtazapine tablets, with bioequivalence required by the regulator. Remeron SolTab (orally disintegrating tablet) is also available for patients with swallowing difficulty.
Forms and dosages
Remeron is supplied as immediate-release tablets in 7.5, 15, 30 and 45mg strengths and as 15/30/45mg orally disintegrating tablets (SolTab). Depression typically starts at 15mg at bedtime, titrated to 30–45mg based on response. The 7.5mg dose is sometimes used for sleep initiation. Once-daily bedtime dosing exploits the sedating effect; food slightly delays peak but does not affect overall absorption.
Indications
Remeron is approved for major depressive disorder. It is widely used off-label for depression with insomnia, depression in elderly patients with poor appetite, depression in patients intolerant of SSRI sexual side effects, and as adjunctive sleep agent in psychiatric practice. According to clinical guidelines, mirtazapine is often considered second-line in major depression but is first-line where its sedating, appetite-stimulating profile aligns with the patient's symptoms.
How it works
Mirtazapine antagonises presynaptic α2-adrenergic receptors, increasing noradrenaline and serotonin release. It also blocks postsynaptic 5-HT2A, 5-HT2C and 5-HT3 receptors, redirecting increased serotonin onto 5-HT1A receptors. It is a potent H1 histamine antagonist, which explains the strong sedative and appetite-stimulating effects, particularly at low doses. Therapeutic antidepressant effect builds over 4–6 weeks of consistent dosing.
Frequently asked questions
Why does low-dose Remeron cause more sedation than higher doses? ▾
At low doses (7.5–15mg), the antihistamine (H1) effect dominates, producing strong sedation. At higher doses, increased noradrenergic transmission counteracts the antihistamine sedation, so 30mg or 45mg is often less sleepy than 15mg. According to clinical practice, this is exploited by using 15mg for insomnia plus depression and titrating up only if depression does not respond.
Is Remeron better tolerated than SSRIs? ▾
Remeron causes notably less sexual dysfunction and gastrointestinal upset than SSRIs but causes more sedation, weight gain and drowsiness. According to current guidelines, the trade-offs make it a preferred second-line agent in patients intolerant of SSRI side effects, particularly when the symptom profile (insomnia, weight loss, low appetite) aligns with mirtazapine's strengths.
Does Remeron cause weight gain? ▾
Increased appetite and weight gain are among the most commonly reported effects of Remeron, particularly at low doses where the H1 antihistamine effect dominates. The effect can be useful in elderly or thin depressed patients with poor appetite but is a problem in patients already overweight. According to clinical practice, weight should be monitored during ongoing therapy and the prescriber may switch agent if gain is unacceptable.
How long does Remeron take to work? ▾
Sedation and improved sleep often appear within the first few nights. Full antidepressant effect develops over 4–6 weeks of continuous bedtime dosing. Patients are typically reviewed at 4–6 weeks to judge response and decide whether to continue, increase the dose or switch agent. Stopping early is a common reason for relapse.
Is Remeron the same as generic mirtazapine? ▾
Yes — Remeron and authorised generic mirtazapine tablets contain the same active ingredient at the same strengths and have demonstrated bioequivalence. The generic is significantly cheaper and clinically equivalent in nearly all cases. The Remeron trademark remains widely recognised but most prescribing today is on the authorised generic.
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The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.