Fluvoxamine (Luvox)

What it treats

Fluvoxamine is approved by the U.S. Food and Drug Administration for obsessive-compulsive disorder in adults and children (age 8 and up). Prescribers also use it off-label for social anxiety disorder, panic disorder, and depression, all of which are supported by evidence even though the FDA labeling in the US doesn't formally cover them.

For OCD specifically, fluvoxamine tends to be dosed higher than most SSRIs and to take longer to show its full effect. Ten to twelve weeks is a fair window.

How it works

Fluvoxamine is a selective serotonin reuptake inhibitor, an SSRI. Nerve cells in the brain pass messages using chemical messengers, and serotonin is one of them. After a cell releases serotonin, it normally reabsorbs much of it, a process called reuptake. Fluvoxamine slows that reabsorption, so more serotonin stays available between cells.

Fluvoxamine also has activity at the sigma-1 (σ1) receptor, which some researchers think matters for its effects in OCD and possibly for cognition. What is clear in practice is that for OCD it works about as well as other SSRIs and clomipramine, and the choice among them often comes down to side effects and interactions.

Receptor mechanism (detail)

Fluvoxamine is a potent serotonin reuptake inhibitor at the SERT transporter with additional sigma-1 (σ1) agonist activity. Clinically, its most distinctive feature is being the strongest CYP1A2 inhibitor among the SSRIs, along with meaningful CYP2C19 and CYP3A4 inhibition.

Potency and typical dosing pattern

Ranges are typical framework only, not a prescription for any individual.

Starting dose for OCD is 50 mg at bedtime. It's titrated up by 50 mg every 4 to 7 days as tolerated, to 100 to 300 mg per day. Doses above 150 mg per day are divided into two doses. Higher doses are often needed for OCD than for depression.

Safety monitoring

• Suicidality in the first 4 weeks, especially under age 25 (FDA boxed warning).
• Drug interactions. This is the big one. Fluvoxamine inhibits multiple liver enzymes and can push levels of many other drugs.
• Serotonin syndrome, avoid MAOIs.
• Bleeding risk with NSAIDs or anticoagulants.
• Hyponatremia in older adults.
• Sexual function.
• Reassess at 2, 4, and 6 to 8 weeks, and again at 10 to 12 weeks for OCD.

What to expect

For OCD, the shape of response is slower than for depression or general anxiety. Some early quieting of obsessions might show at 4 to 6 weeks, but a meaningful reduction often needs 8 to 12 weeks at a therapeutic dose. That patience is part of treating OCD.

Early side effects tend to arrive before benefits. Nausea, sedation, and headache are common in the first week or two and usually settle.

Common side effects

Most people get some side effects. The common ones include:

• Nausea, often the most noticeable early on.
• Drowsiness. Fluvoxamine is more sedating than most SSRIs, which is why it's usually taken at bedtime.
• Trouble sleeping (for others, in the other direction).
• Headache.
• Dry mouth.
• Fatigue.
• Sexual side effects.
• Constipation.

Many of the stomach-related effects ease within one to two weeks. Sexual side effects tend to last as long as the medication is taken.

Serious side effects and warnings

Serious problems are uncommon, but a few are worth knowing.

Boxed warning. Like all antidepressants, fluvoxamine carries an FDA boxed warning that it can increase suicidal thoughts and behaviors in children, teenagers, and young adults under 25, especially in the first weeks of treatment or after a dose change. This does not mean the medication harms most people. It means the early period deserves close attention, and that any worsening of mood, agitation, or new thoughts of self-harm should prompt contact with the prescriber promptly.

• Serotonin syndrome. A rare reaction caused by too much serotonin activity, most likely when fluvoxamine is combined with other drugs that raise serotonin. Signs include agitation, a fast heartbeat, high body temperature, shivering, muscle twitching, and confusion. It is a medical emergency.
• Increased bleeding risk. Fluvoxamine can make bleeding and bruising more likely, especially alongside NSAIDs, aspirin, or blood thinners.
• Low sodium. A drop in blood sodium can happen, more often in older adults.
• Mood switch in bipolar disorder. In people who have bipolar disorder, an antidepressant can sometimes trigger a manic or agitated state.
• QT prolongation at higher doses, particularly when combined with other QT-prolonging drugs.

Sexual side effects

Fluvoxamine, like other SSRIs, commonly affects sexual function. It can lower sex drive, delay orgasm or make it hard to reach, and cause arousal or erection difficulties. Rates are broadly similar to other SSRIs.

These effects usually last as long as the medication is taken, rather than fading like nausea does. They are worth raising with a prescriber, because there are real options: lowering the dose, switching to a medication less likely to cause this such as bupropion, or adding another medication to counter it. A small number of people report sexual side effects that continue after stopping the drug. This is uncommon and not well understood, but it is a real phenomenon and worth knowing about before you start.

Weight, appetite, and sleep

Fluvoxamine is roughly weight-neutral for many people, though some weight gain over months is possible. Sleep effects tilt sedating, which is why it's usually taken at bedtime. For people whose insomnia is driven by racing OCD thoughts, that sedation can be welcome.

Starting and dosing basics

This section is general background, not a dosing instruction for any individual. The right dose is a decision for a prescriber.

Fluvoxamine comes as immediate-release tablets and as extended-release capsules (Luvox CR). The immediate-release form is taken once or twice daily; the ER form is taken once daily. It's started low and increased over several weeks. Doses above 150 mg per day are usually split into a morning and evening dose.

Missed doses and interactions

If you miss a dose, take it when you remember unless it's close to the next scheduled dose. Don't double up.

Interactions are the standout feature of fluvoxamine, and this section matters more than it does for most SSRIs. Fluvoxamine inhibits CYP1A2 strongly, and it also inhibits CYP2C19 and CYP3A4. This affects a long list of medications:

• Clozapine: fluvoxamine can more than triple clozapine levels. This combination has to be managed very carefully or avoided.
• Theophylline: raised levels, seizure risk.
• Caffeine: fluvoxamine slows caffeine metabolism, so people often feel jittery from smaller amounts.
• Warfarin: raised INR, bleeding risk.
• Ramelteon and melatonin: fluvoxamine massively raises ramelteon levels; the combination is contraindicated.
• Tizanidine: contraindicated (severe hypotension).
• Some tricyclic antidepressants and antipsychotics (like olanzapine): raised levels.
• MAOIs: contraindicated (serotonin syndrome).

Alcohol adds to sedation and isn't recommended. Give every prescriber and pharmacist a full list of your medications and supplements, including over-the-counter ones.

Stopping and tapering

Fluvoxamine is not addictive in the usual sense. It doesn't cause cravings or compulsive use. But the body does adjust to it, and stopping suddenly can cause discontinuation symptoms: dizziness, flu-like feelings, irritability, vivid dreams, trouble sleeping, and the brief electrical "brain zap" sensations many people describe. Fluvoxamine has a relatively short half-life, so discontinuation symptoms can be more pronounced than with fluoxetine.

A gradual taper planned with a prescriber, stepping the dose down over weeks, is the way to avoid this.

Pregnancy and breastfeeding

This is an area where individual circumstances matter and the decision belongs with a clinician. Untreated OCD and depression carry their own risks during pregnancy. Fluvoxamine passes into breast milk.

Anyone who is pregnant, planning a pregnancy, or breastfeeding should talk it through with their prescriber so the specific risks and benefits can be weighed.

Cost and generic availability

Fluvoxamine has been available as a generic for many years. The brand name Luvox was discontinued in the US, though the ER form (Luvox CR) is still branded. Generic fluvoxamine contains the same active medication and works the same way.

Common questions

Why is fluvoxamine used for OCD specifically? It works well for OCD, and it was one of the first SSRIs approved for that use. All SSRIs and clomipramine are options; fluvoxamine is one of several reasonable choices.

Why does my prescriber care so much about caffeine? Fluvoxamine slows caffeine's metabolism, so the caffeine you drink hangs around longer. Two cups of coffee can feel like five. Cutting back is often useful.

How long until it works? For OCD, allow 8 to 12 weeks at a therapeutic dose. Some early quieting may show sooner, but the fuller effect takes longer than for depression.

Is fluvoxamine addictive? No, not in the usual sense. It doesn't cause cravings or compulsive use. The body does adapt to it, which is why stopping should be gradual.

Can I drink alcohol while taking it? It isn't formally banned, but it isn't recommended. Alcohol adds to sedation and undercuts the benefit.

Questions to ask your prescriber

• What are we hoping this treats, and how will we know it's working?
• With all my other medications, does fluvoxamine interact with any of them?
• Should I cut back on caffeine while I'm on it?
• How long should I plan to take it?
• If we decide to stop it later, how would we do that safely?

Sources

This guide draws on current prescribing information and public health references. It is reviewed for clinical accuracy and updated as guidance changes, and current as of June 8, 2026.

• U.S. Food and Drug Administration. Fluvoxamine (Luvox) prescribing information.
• MedlinePlus, U.S. National Library of Medicine. Fluvoxamine.
• National Institute of Mental Health. Mental health medications.
• American Psychiatric Association. Practice guideline for the treatment of patients with obsessive-compulsive disorder.
• National Institute for Health and Care Excellence (NICE). CG31, Obsessive-compulsive disorder and body dysmorphic disorder.