Weight Change After Stopping Olanzapine (Zyprexa): What to Expect

Most people lose some weight after stopping olanzapine, because the drug's strong push on appetite fades once it leaves the body. The loss is usually slow and partial, unfolding over roughly 3 to 12 months, and it rarely erases all the weight gained. The first 2 to 4 weeks can bring a different pattern, with nausea or poor sleep moving the scale in either direction.

Olanzapine (Zyprexa) is one of the antipsychotics most strongly linked to weight gain. That makes weight change after stopping olanzapine one of the first things people ask about when they plan to come off it. This guide covers what the research shows, a realistic timeline, why some people regain, and how to protect both your weight and your mental health during the taper.

Olanzapine weight change timeline after stopping, month by month

Weight change after stopping olanzapine follows a rough pattern, though research on the exact timeline is thin. Most studies tracked weight while people took olanzapine, not after they stopped. The table below combines that research with the pharmacology of the drug and the patterns people in our community consistently report. Treat it as a typical course, not a promise.

Time since last dose	What usually happens to appetite	What usually happens to weight
Weeks 1 to 2	Withdrawal effects such as nausea, sweating, and poor sleep can dull or scramble hunger	Small drops of a few pounds are common, mostly fluid and lower intake
Weeks 3 to 8	Constant hunger and carbohydrate cravings start to ease	Weight often stabilizes, then begins a slow downward drift
Months 2 to 6	Fullness signals feel closer to normal for many people	Gradual loss for many people, measured in pounds per month rather than per week
Months 6 to 12	Eating habits built on the drug become the main driver	Loss slows and usually plateaus above pre-olanzapine weight
After 12 months	Appetite is no longer drug-driven	Further change depends on diet, activity, sleep, and mood

Olanzapine has a half-life of about 21 to 54 hours according to the FDA prescribing information for Zyprexa. The drug is mostly cleared within about 7 to 10 days of the final dose. Appetite takes longer to reset because the body has adapted to months or years of blocked hunger signals.

Bottom line: weight change after stopping olanzapine is a slow drift over months, not a sudden drop, and the first two weeks say little about where weight will settle.

Why olanzapine causes weight gain in the first place

Olanzapine causes weight gain mainly by blocking two receptors that control appetite. It blocks histamine H1 receptors and serotonin 5-HT2C receptors in the brain, and both normally help tell you that you are full. With those signals muted, hunger rises and meals stop feeling satisfying.

The size of the effect is large. A 1999 meta-analysis in the American Journal of Psychiatry by Allison and colleagues estimated that olanzapine added about 4 kg (9 pounds) in the first 10 weeks of treatment, more than most other antipsychotics. In the CATIE trial published in the New England Journal of Medicine in 2005, people on olanzapine gained an average of about 2 pounds per month, more than any other drug in the study.

A 2020 network meta-analysis in The Lancet Psychiatry by Pillinger and colleagues, covering 100 trials, placed olanzapine among the worst antipsychotics for weight, cholesterol, and blood sugar. Olanzapine also slows how the body handles glucose and fat. Some of that metabolic shift happens independently of how much a person eats.

Drug-induced weight gain is weight gain caused by a medication's direct effect on appetite and metabolism rather than by a change in willpower or habits. That distinction matters after stopping. Removing olanzapine removes the cause, but the weight already gained has to come off the ordinary way.

Bottom line: olanzapine raises hunger and changes metabolism at the same time, which is why the weight comes on fast and leaves slowly.

What the research says about weight loss after stopping Zyprexa

The best evidence on weight loss after stopping Zyprexa (olanzapine) comes from studies where people moved off olanzapine for metabolic reasons. A 2010 Cochrane review of antipsychotic switching for weight and metabolic problems by Mukundan and colleagues found that people who stopped olanzapine lost more weight and had better blood sugar than those who stayed on it. The difference was a few kilograms over several months, not a full reversal.

That finding fits the pharmacology. When olanzapine is gone, the appetite-blocking effect is gone too. The body does not automatically shed the stored fat, though. Lower hunger makes weight loss possible; it does not do the work by itself.

Few studies have followed people who stopped antipsychotics completely and tracked weight for a year or longer. That is a real gap in the research. Most of what is known about the long tail comes from clinical experience and from patients comparing notes in forums.

Patients in our community consistently report that the first clear sign of change is not on the scale. It is the moment a meal ends with a sense of fullness again, often somewhere between week 3 and month 3. Weight loss tends to follow that shift by weeks to months.

Bottom line: stopping Zyprexa reliably reduces the drive to overeat, and research shows modest weight loss over months, but the full gain rarely disappears on its own.

I gained 30 pounds on Zyprexa. Will the weight come off when I stop olanzapine?

Some of it usually comes off, and the amount depends on how long you took olanzapine and what changed in your habits along the way. People who gained quickly over a short course tend to lose more of it than people who carried the weight for years.

Several factors shape how much weight change after stopping olanzapine you can expect. The table below summarizes the ones that matter most.

Factor	Tends to help weight loss	Tends to slow weight loss
Time on olanzapine	Months	Many years
Eating pattern built on the drug	Few new habits formed	Night eating, large portions, sugary drinks
Sleep after stopping	Sleep returns within weeks	Ongoing insomnia, which raises hunger hormones
Blood sugar and cholesterol	Normal on recent tests	Prediabetes or high triglycerides
Mood after stopping	Stable	Relapse, low mood, or comfort eating
Activity level	Rising as sedation lifts	Still low because of fatigue

Sedation matters more than people expect. Olanzapine is heavily sedating, and many people move far less while taking it. As that lifts, energy for walking and daily activity often returns, which helps.

Bottom line: expect to lose part of the weight, with the biggest gains for people who took olanzapine for a shorter time and who protect their sleep after stopping.

Can you gain weight after stopping olanzapine?

Yes, some people gain weight after stopping olanzapine, usually for one of three reasons. Each has a different cause and a different fix.

The first reason is rebound insomnia. Olanzapine blocks histamine strongly, and stopping it can cause weeks of poor sleep. Short sleep raises hunger hormones and cravings, so people eat more at night. The stopping olanzapine suddenly guide covers this cholinergic and histamine rebound in detail.

The second reason is relapse or low mood. If anxiety, depression, or psychotic symptoms return, eating patterns often change. A relapse can also lead to a restart of olanzapine or a similar drug, which brings the appetite effect back.

The third reason is habit. Larger portions and night snacking that began on the drug can continue after the drug is gone. Without the chemical push, these habits are easier to change, but they do not change on their own.

Weight change after stopping olanzapine is therefore not one-directional. Tracking sleep, mood, and weight together makes the cause easier to spot early.

Bottom line: gaining weight after stopping olanzapine usually points to poor sleep, returning symptoms, or leftover habits, not to the drug itself.

Should you stop olanzapine to lose weight, and how fast?

Weight is a valid reason to reconsider olanzapine, and many people raise it with their prescriber for exactly that reason. The risk is stopping too fast. Rapid discontinuation raises the chance of withdrawal symptoms and relapse, and a relapse can undo any weight benefit.

A 2021 JAMA Psychiatry paper by Horowitz, Murray, and Taylor on tapering antipsychotic treatment argues for gradual, hyperbolic reductions over many months. Hyperbolic tapering is a method where each dose reduction is a percentage of the current dose, so the steps get smaller as the dose gets lower. The same principle comes from the 2019 Lancet Psychiatry paper by Horowitz and Taylor on antidepressant tapering, because receptor occupancy drops steeply at low doses.

The Canadian Deprescribing Network's antipsychotic deprescribing resources also support slow, monitored reductions with follow-up after each step. Our olanzapine (Zyprexa) tapering guide explains the principles, and the taper planner shows how proportional cuts shrink as the dose falls.

Here is what to bring to the conversation with your prescriber:

• Your weight before starting olanzapine and your weight now
• Recent blood sugar, HbA1c, and cholesterol results
• Your history of relapse when doses were changed before
• A request for small, percentage-based reductions with check-ins between them

The Royal College of Psychiatrists' guide to antipsychotics also describes why stopping should be gradual and supported.

Bottom line: weight loss is a good reason to taper olanzapine, and a slow taper protects that goal better than a fast one.

What should I do if I'm still hungry all the time months after stopping Zyprexa?

Persistent hunger months after stopping Zyprexa (olanzapine) is common and usually improves. The drug is gone within about 7 to 10 days, but the body's appetite system may take months to recalibrate after long exposure.

Start with sleep, because poor sleep is the most common driver of hunger after olanzapine. A consistent wake time, daylight in the morning, and no late caffeine help more than most diet changes during this phase. Protein and fiber at each meal also help fullness signals register, which olanzapine had muted.

Check your metabolic health. Olanzapine can push blood sugar and insulin out of range, and insulin resistance keeps hunger high even after the drug is gone. Ask for a fasting glucose or HbA1c test if you have not had one recently. Prescribers can treat these problems directly, and treating them often reduces cravings.

Keep a simple record of sleep, hunger, mood, and weight each week. A taper and symptom journal makes slow trends visible, which matters when change happens over months. It also gives your prescriber real data rather than memory.

Other people who have come off antipsychotics share practical experience in the Inner Compass Initiative's Withdrawal Project and in reporting from Mad in America on antipsychotic withdrawal. Our community forums are another place to compare notes with people at the same stage.

Bottom line: lingering hunger after stopping Zyprexa usually reflects poor sleep, metabolic changes, or slow appetite recovery, and all three can be checked and addressed.

Frequently asked questions

Do you lose weight after stopping olanzapine?

Most people lose some weight after stopping olanzapine, usually slowly over 3 to 12 months. The loss is often partial. A 2010 Cochrane review found that people who moved off olanzapine lost a few kilograms more than those who stayed on it.

How long after stopping olanzapine does appetite go back to normal?

Appetite usually starts to settle between 3 weeks and 3 months after stopping olanzapine. People who took it for many years often report a slower return. Poor sleep after stopping can delay the change.

Can you gain weight after stopping Zyprexa?

Yes. Rebound insomnia, returning mood symptoms, and eating habits formed on the drug can all cause weight gain after stopping Zyprexa. These causes are different from the drug's direct effect, and each one can be addressed.

Is weight loss in the first week after stopping olanzapine a withdrawal symptom?

Often, yes. Nausea, vomiting, sweating, and poor sleep in the first 1 to 2 weeks after stopping olanzapine can cause a quick drop of a few pounds. That early loss is mostly fluid and lower intake, not fat loss.

I've been on olanzapine for 5 years and my doctor says I can just stop. Will I lose the weight faster that way?

No. Stopping olanzapine abruptly does not speed up fat loss, and it raises the risk of withdrawal symptoms and relapse. A gradual, percentage-based taper reaches the same weight benefits with less risk to your mental health.

Weight after olanzapine: the bottom line

Weight change after stopping olanzapine is real and usually favorable. Appetite tends to settle over weeks to months, and weight drifts down slowly over the following year. The biggest risks to that outcome are poor sleep, returning symptoms, and stopping too quickly. Read the Zyprexa (olanzapine) drug profile for dosing forms and half-life details, and compare it with related antipsychotics such as Seroquel (quetiapine) and Abilify (aripiprazole).

taper.community is a free peer-support site and forum where people coming off psychiatric drugs, including antipsychotics, plan slow proportional tapers together. If you are planning to come off olanzapine, the tapering plan worksheet helps you prepare, and you can find a deprescribing-aware clinician to support the process.

This article is for educational purposes only and is not medical advice. Do not stop or change any medication without the guidance of a qualified healthcare provider. Antipsychotic discontinuation can lead to withdrawal symptoms and relapse, so any change should be gradual and monitored.