Yvessa Draft Lab

Educational reading only - this desk does not run a pharmacy, fill a script, or replace the clinician who holds your chart. Read the plan disclaimer

Plan · CNS

Adult depression starts at 20 mg in the morning

Last reviewed · 13 min read · Updated

Prozac 20 mg is the labelled adult start for major depression when the capsule is taken in the morning. Lilly's US label also opens OCD at 20 mg in the morning. Panic starts lower. Bulimia is a 60 mg morning dose.

Benefit can sit out five weeks or longer. Activation can show in the first fortnight. The parent drug and norfluoxetine keep serotonin reuptake blocked after the last swallow, which is why a five-week gap sits in front of an MAOI.

Plan card

Yvessa lockFluoxetine 20 mg capsule
Adult MDD start20 mg once daily in the morning
OnsetActivation days 1-14; mood often 2-5 weeks
Half-lifeParent ~1-6 days; norfluoxetine ~4-16 days
FoodWith or without meals
Hard stopMAOI: 14 days after MAOI, 5 weeks after Prozac
Ceiling80 mg/day on the US label
Prozac 20 mg capsules in a short row

Why the uses page locks the 20 mg capsule

People type Prozac 20 mg uses because that is the adult depression start on the US label, not a marketing rung. Morning dosing is written into the same line.

OCD in adults opens at the same 20 mg morning dose. Panic opens at 10 mg. Bulimia nervosa is 60 mg in the morning. Combination olanzapine plus fluoxetine is a different product story.

Amelie files the 20 mg capsule as the Yvessa lock because GoodRx quotes that strength as a thirty-count. Tablets are another board. The activation markup sits beside first-week jitter. The washout draft keeps the five-week MAOI gap from getting shortened.

GoodRx average retail$9.00
GoodRx coupon print$9.00

Generic fluoxetine 20 mg x 30 capsules, GoodRx Prozac capsule table, 08 July 2026.

Generic fluoxetine 20 mg capsules, thirty count, the Yvessa Prozac plan lock, August 2026. GoodRx lists 20 mg x 30 capsules at $9.00 retail and $9.00 with a coupon (08 July 2026). The 20 mg tablet board is a different line. Washout before an MAOI still applies. Yvessa does not prescribe.

Hyponatremia, SIADH, and the question nobody asks

Fluoxetine can drop sodium through SIADH. Older adults and people on diuretics sit at higher risk. Headache, poor concentration, confusion, and unsteadiness are the early picture. Symptomatic hyponatremia is a reason to stop and treat the sodium, not to 'push through week two'.

A routine chemistry after start is not on every label as a calendar, but a confused 78-year-old on 20 mg and a thiazide is a same-week lab, not a philosophy debate.

Sexual dysfunction is labelled. The PI tells prescribers to ask before the first capsule and again later, because people will not volunteer it. Timing of the complaint matters: if function fell in week one, activation and anxiety may be the driver; if it fell after mood lifted, the SSRI is the usual suspect.

Do not promise that a weekend hold will clear sexual sides. Norfluoxetine is still there. A structured pause is a prescriber plan, not a Friday experiment.

Notes Amelie keeps in the margin

Rue du Rhone walk-in clinics sometimes write 20 mg 'for sleep'. Fluoxetine is a poor hypnotic. Insomnia is a common early effect. Redirect that script.

A student who wants 20 mg 'just for exams' is asking for an unlabelled course. This desk stamps licensed uses only.

Cross-border French boxes still need the five-week MAOI sentence in the language the patient reads.

If fluvoxamine later appears for OCD, remember the other CNS lock: fluvoxamine plus tizanidine is a contraindication on the spasm sheet. The 20 mg Prozac story and the 2 mg Zanaflex story collide in that rare pair.

Who should not swallow the first 20 mg

Anyone on a psychiatric MAOI, or inside the 14-day inbound gap, does not start. Anyone who needs thioridazine or pimozide does not add Prozac.

Known hypersensitivity to fluoxetine is a stop. Uncontrolled narrow-angle glaucoma deserves a prescriber look before any SSRI.

Pregnancy and lactation decisions are not a Geneva web page. The label carries fetal and neonatal notes. The prescriber holds that conversation.

Yvessa does not prescribe. Mail to [email protected] is for sourcing slips on this sheet, not a dose change.

What a three-week gap actually means

A traveller who leaves the 20 mg bottle in Geneva and goes two weeks without it still has norfluoxetine on board. Restarting at 20 mg is usually straightforward. Restarting at 40 mg because 'I felt the old depression coming' is a rise the prescriber should own.

If the gap is longer than a month, treat the next swallow like a new start for activation and suicide watch, even if the person 'knows this drug'.

Insurance step-edits sometimes force a tablet instead of a capsule. Kinetics follow the INN. Food rules do not suddenly appear. Washout does not shorten.

Mail-order 90-day boxes do not change the morning clock. They do change how long a bad interaction can run if nobody reviews the list.

Leaving 20 mg for another antidepressant

Because plasma lags, a same-week hop to another SSRI can still be a serotonergic stack. Cross-tapers belong on paper with dates, not in a text message.

If the destination is an MAOI, the outbound gap is five weeks. If the destination is thioridazine, the same five-week wall applies. Those are contraindications, not 'use clinical judgment to shorten'.

If the destination is a short-half-life SSRI, some desks still wait a week or more after the last 20 mg before the new daily start, then watch for serotonin-syndrome signs. That wait is not as long as the MAOI rule and should not be confused with it.

Discontinuation symptoms with fluoxetine are milder than with paroxetine for many people, precisely because the tail is long. That comfort is not a licence to stop 80 mg overnight without a plan if the person has been on a high dose for years.

Olanzapine-fluoxetine combination products are a separate stop. Pulling only the 20 mg capsule while a combo blister continues is how double-counts happen.

Why week two is a poor verdict

The US label says the full therapeutic effect may be delayed until five weeks of treatment or longer. That sentence is why a day-ten 'this does nothing' call is premature unless safety flags appear.

Fluoxetine half-life after acute dosing sits near 1-4 days and stretches toward 4-6 days with chronic use. Norfluoxetine, the active demethylated metabolite, runs 4-16 days. Steady state for the pair takes about a month.

Dose changes will not be fully reflected in plasma for several weeks. The same clock applies when someone stops. That is section 5.14 language, not desk folklore.

Morning dosing is the labelled default because insomnia and activation show up early. Moving the capsule to evening without a reason often worsens sleep.

ADME plan card
AbsorptionOral absorption is good; peak around 6-8 hours. Food does not force a meal timer the way sildenafil does.
DistributionHighly protein-bound; wide volume; crosses placenta and appears in milk.
MetabolismHepatic CYP2D6 (and other CYPs) to norfluoxetine. Fluoxetine also inhibits CYP2D6.
ExcretionMetabolites leave in urine. Parent t1/2 ~1-6 days; norfluoxetine ~4-16 days, longer in older adults and hepatic impairment.

Fourteen days one way, five weeks the other

Do not use an MAOI meant for psychiatric illness with Prozac. Do not start Prozac within 14 days of stopping that MAOI. After the last Prozac capsule, wait at least five weeks before starting the MAOI.

Linezolid and intravenous methylene blue sit on the same serotonin-syndrome contraindication. Those are not 'ask the pharmacist if they feel close enough' exceptions.

The five-week outbound gap is norfluoxetine. A two-week habit copied from shorter SSRIs is the switch error this desk sees most.

Thioridazine is contraindicated with Prozac and for five weeks after the last capsule because CYP2D6 inhibition plus QT risk is a labelled wall. Pimozide is also contraindicated.

Jitter that arrives before calm

Activation - restlessness, worse sleep, a spike in anxiety - can land in the first one to two weeks. Fluoxetine is not the only SSRI that does this. The long tail means stacked early increases can keep that feeling going.

If the restlessness is tolerable, hold the 20 mg and look again at week three before calling the start a failure. If agitation brings new suicidal intent or a manic switch, that is same-day review.

GI upset and headache sit in the same early window. They often fade. New mania, serotonin-syndrome signs, or a bleeding event do not get a 'wait it out' stamp.

Clock the first month, not the first weekend

Days 1-7

Insomnia, nausea, restlessness possible. Morning dose stays unless the prescriber moves it.

Days 8-14

Activation peak for many. Sleep hygiene first. Do not jump to 40 mg on day nine.

Weeks 3-5

Mood change may finally show. Label allows a rise after several weeks.

After stop

Parent and norfluoxetine linger. Plan the next serotonergic drug on that clock.

What the Geneva counter says about the 20 mg start

Name the indication. A 20 mg depression start is not a silent 60 mg bulimia script. The blister does not explain that.

Tell people activation can precede benefit. Point them to the activation markup so week-one insomnia is not treated as proof of the wrong drug.

Missed capsule: take when remembered unless it is nearly time for the next. Do not double. The long half-life forgives a single miss more than a rushed switch.

Generic 20 mg capsules with a legitimate MA number follow the same washout. Colour of the gelatin is not a kinetic claim.

The boxed line on young adults

Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults. That boxed warning is on every Prozac label. Families need a watch plan for the first months and after dose changes.

Worsening depression, new agitation, or unusual behavior changes are stop-and-call events. They are not proof the 20 mg 'is working because feelings are moving'.

Sexual dysfunction is a labelled SSRI effect. It can appear after mood has already lifted, which is why people blame the relationship first.

Identity for the 20 mg uses lock
INN / lockFluoxetine / Prozac 20 mg capsule
ClassSSRI
Active metaboliteNorfluoxetine
Adult MDD open20 mg morning
Max80 mg/day
BoxedSuicidality in young people

CYP2D6 traffic the capsule creates

Fluoxetine is a CYP2D6 inhibitor. That matters for tamoxifen activation, for some tricyclics, and for a short list of antipsychotics already named as contraindications.

NSAIDs, aspirin, and anticoagulants raise bleeding risk with SSRIs. The label does not treat that as a rare curiosity. Ask about the pain-tablet drawer.

Serotonergic stacks - other SSRIs, SNRIs, triptans, lithium, St John's wort, tramadol - raise serotonin-syndrome risk. The long half-life means a 'stopped last Tuesday' history is still a stack.

Hepatic impairment stretches exposure. Renal failure alone rarely forces a fluoxetine cut because clearance is hepatic. Older adults still need a slower rise.

Interaction lanes on the 20 mg sheet

  • Absolute: MAOI (timing rules above), thioridazine, pimozide, linezolid, IV methylene blue
  • Watch: NSAIDs, warfarin, other serotonergic drugs, tamoxifen, some beta-blockers via 2D6
  • Alcohol: labelled caution for judgment and additive CNS effects - not a free pass

What the label actually licenses at 20 mg

Major depressive disorder in adults: start 20 mg orally in the morning. After several weeks with a thin response, the prescriber may raise the dose. Amounts above 20 mg can stay once daily in the morning or split morning and noon.

Obsessive-compulsive disorder in adults also starts at 20 mg in the morning. Trials used 20, 40, and 60 mg. One of those studies did not show a clean dose-response curve. The ceiling is still 80 mg/day.

Bulimia nervosa is 60 mg in the morning, not a 20 mg start that someone later 'feels toward'. Panic disorder starts at 10 mg. Bipolar I depressive episodes and treatment-resistant depression use fluoxetine with olanzapine; those starts are 20 mg fluoxetine plus 5 mg olanzapine in adults.

Pediatric MDD and OCD have their own 10-20 mg openers. This sheet is the adult 20 mg capsule lock. A child dose is a separate script.

Adult uses that share the INN - doses are not interchangeable
Labelled useAdult openNote on this lock
MDD20 mg morningYvessa 20 mg capsule
OCD20 mg morningMay rise after weeks
Bulimia60 mg morningNot the 20 mg start
Panic10 mg firstDifferent open
Olanzapine combo20 mg + 5 mg olanzapineSymbyax-class lane

Stamp before the 20 mg bottle leaves

Survey: current Prozac label, boxed warning, 20 mg morning line, five-week MAOI outbound gap.

Draft: INN on the line, capsule not tablet unless the script says tablet, bulimia 60 mg not smuggled into a depression start.

Peer-check: Amelie confirms thioridazine and pimozide stay off the list. Stamp 21 August 2026. Change nothing without the prescriber. Disclaimer at blueprint disclaimer.

Sources

  1. FDA / Lilly Prozac (fluoxetine) prescribing information - indications, dosing, boxed warning, 5.14 half-life.
  2. DailyMed PROZAC-fluoxetine hydrochloride capsule - adult and pediatric dose table.
  3. US label contraindications - MAOI, thioridazine, pimozide, linezolid, IV methylene blue.

Checked against the current label and reviewed by Dr. Amélie Laurent. See Survey, Draft, Peer-check, Stamp.

Fluoxetine 4.6 / 5 from 3350 reader ratings

Plan thread

Dr. Amelie Laurent answers reader mail on the Rue du Rhone desk. Educational only. Yvessa does not prescribe. [email protected] is for sheet corrections, not a new dose.

Nadine, Eaux-Vives My GP wrote Prozac 20 mg. I feel worse on day six. Do I stop?

Desk reply

Early worsening can be activation - restlessness, thin sleep, a tighter chest of anxiety - and it is common enough in the first fortnight that the label tells people not to judge benefit that early. The same week can also unmask suicidal thinking, especially under 25, which is the boxed warning, not a counselling slogan. If the 'worse' is agitation with new intent, or a manic high, that is same-day care, not a hold-the-capsule experiment. If it is jitter and nausea you can live with, the usual move is stay on 20 mg and review at week three, not jump to 40 mg on day six. Bring a sleep log to the prescriber. The activation markup is the short version of that fortnight. Yvessa will not tell you to stop or stay. The person who signed the script owns that call.

Clara, Carouge Can I take the 20 mg capsule at night so I sleep through nausea?

Desk reply

The adult depression and OCD lines say morning. That is not a style choice. Fluoxetine is activating for a lot of people, and evening dosing can wreck sleep. If morning nausea is the only problem, taking the capsule with food is allowed - there is no sildenafil-style fat lock. A prescriber can move the clock after they hear the sleep story. Do not move it yourself because a forum said night is gentler. Panic starts at 10 mg, which is a different open if the 20 mg morning dose is simply too much stimulation in week one.

Samir, internist Hepatic impairment - cut the 20 mg start?

Desk reply

Clearance is hepatic. Impairment stretches half-life further. Lower and slower is the usual labelled instinct. Renal failure alone rarely forces a fluoxetine cut. Older adults still accumulate. A 20 mg start can stay 20 mg if the prescriber chooses, but the rise after 'several weeks' should be slower than in a healthy 30-year-old. Judge efficacy later, not at day ten, because plasma will lag even more.

Priya, oncology liaison Patient on tamoxifen. New fluoxetine 20 mg from a walk-in clinic. Keep both?

Desk reply

Fluoxetine inhibits CYP2D6. Tamoxifen needs 2D6 to make endoxifen. Many oncology desks avoid strong 2D6 inhibitors here. This is a same-week call to the prescriber who owns the cancer plan, not a 'monitor and see' default. Do not stop tamoxifen on a web page. Do not assume 20 mg is too small to matter. Document the start date. Norfluoxetine will still be around if fluoxetine is later pulled.

Louise, reader in Lyon Generic 20 mg from a French pharmacy - same five-week story?

Desk reply

If the MA number is real, norfluoxetine does not care which factory printed the capsule. The washout is the molecule. Yvessa does not vet vendors. Cross-border boxes still need the Swiss or EU prescriber in the loop. A cheaper capsule is not a shorter half-life. Colour and size are not kinetic claims. If the leaflet language disagrees with this sheet, follow the leaflet you were handed and mail [email protected] if you found a sourcing slip.

Theo, pharmacy student Why five weeks off Prozac before an MAOI when other SSRIs use two?

Desk reply

Because norfluoxetine is still an SSRI after the parent drug has fallen. Label half-life for the metabolite is 4-16 days. The outbound rule is at least five weeks after the last Prozac dose before a psychiatric MAOI. The inbound rule is the other direction: at least 14 days after the MAOI before starting Prozac. Copying a two-week habit from sertraline or citalopram is how serotonin syndrome gets written up. Thioridazine has the same five-week outbound wall for a QT and CYP2D6 reason. The washout draft is the pocket card we clip to the chart.

Marc, father of 19-year-old The boxed warning scared us. Is 20 mg banned under 25?

Desk reply

No. The boxed warning is increased risk of suicidal thinking and behavior in children, adolescents, and young adults. It is a monitor order, not an age ban on the 20 mg capsule. Families need a concrete watch: new agitation, talk of death, giving things away, sudden calm after despair. The first months and every dose change are the high-watch windows. Depression itself carries suicide risk. The warning does not mean untreated illness is safer. If you see those signs, same-day clinical contact. Swiss emergency is 144 for immediate danger.

Hugo, 76, on a thiazide I feel foggy on day twelve of 20 mg. Is that activation?

Desk reply

Fog, headache, and unsteadiness in an older adult on an SSRI plus a diuretic is hyponatremia until a lab says otherwise. SIADH is labelled. Activation is restlessness and worse sleep, more often in the first fortnight, and it does not usually look like confusion in a 76-year-old. Get a sodium the same week. Do not raise to 40 mg while foggy. Do not stop every tablet at once without telling the prescriber if you have been on 20 mg only twelve days - that start is still short, but the sodium comes first. Falls in that week are an emergency-department problem, not a 'wait for week five benefit' problem.

Elena, bulimia clinic Insurance approved 20 mg. Label for bulimia is 60. Can she titrate at home?

Desk reply

Adult bulimia nervosa on the US label is 60 mg in the morning. That is not a 20 mg start that the patient raises on a calendar. A 20 mg depression open is a different indication. If the script says bulimia and the box says 20, call the prescriber. Do not triple capsules to 'match the monograph'. Missed swallows and purging change exposure in ways a home ladder cannot track. This desk will not write a home titration. The person who named the indication owns the milligrams.

Jonas, shift nurse I take ibuprofen most nights. Is that a real bleed risk with Prozac?

Desk reply

SSRIs plus NSAIDs raise bleeding risk. The label treats it as a counselling point, not a trivia line. Aspirin and anticoagulants sit in the same stack. A nightly ibuprofen habit belongs on the med list. It is not an automatic ban for every sprain, but it is a reason to ask the prescriber about a different pain plan if the NSAID is chronic. Watch for black stool, unusual bruising, or a bleed that will not stop. Those are clinic or emergency events, not 'wait for the 20 mg to settle'.

Amelie desk What must be said before the first 20 mg Prozac capsule?

Desk reply

Morning start for adult depression. Benefit may wait five weeks. Activation can come first. Boxed watch for suicidality in the young. Five weeks off before an MAOI. Fourteen days after an MAOI before start. No thioridazine, no pimozide, no linezolid or IV methylene blue. List NSAIDs and other serotonergic drugs. Yvessa pages are study sheets. The pharmacy stamp is where legal supply happens. Talk to the prescriber or pharmacist before changing a dose. Read the blueprint disclaimer.