Zyprexa weight gain (olanzapine): All you need to know

Key Points

• Zyprexa (Olanzapine) is an antipsychotic medication that can lead to weight gain as a side effect
• A greater appetite is a common side effect, often within the first four weeks
• Balanced nutrition, regular physical activity, and mindful eating can help minimize weight gain on Zyprexa
• A registered weight loss dietitian can develop a personalized nutrition plan to manage Zyprexa weight gain

When you take Zyprexa, your brain and body are locked in a complex chemical tug-of-war.

This powerful antipsychotic may treat serious mental health conditions, but it also disrupts the hormones that control hunger and metabolism. For the millions managing schizophrenia or bipolar disorder with this medication, this creates a genuine health dilemma and an additional burden during an already challenging time.

Learning about how Zyprexa makes you gain weight can help you develop approaches to help balance the medication’s benefits with its side effects, like weight gain.

What is Zyprexa?

Zyprexa is the brand name for olanzapine, an antipsychotic medication. It works by balancing certain neurotransmitters in the brain to manage symptoms of schizophrenia and bipolar disorder.

However, olanzapine also comes with its fair share of side effects, and weight gain is a common one.

Does Zyprexa (Olanzapine) make you gain weight?

Zyprexa can lead to weight gain, although results vary based on each individual’s response to the medication.

A study that followed people with schizophrenia for three years during antipsychotic treatment found that between 34-55% of patients who started at normal weight or underweight gained at least 7% of their body weight.

In another study focusing specifically on olanzapine (the generic name for Zyprexa) at doses between 5-15 mg, about two-thirds of people gained between 2.2-11 pounds in just four weeks. Women over 40 appeared more likely to experience significant weight gain compared to younger women or men of any age.

How does Zyprexa cause weight gain?

"Zyprexa can have a noticeable impact on weight," explains Rita Faycurry, RD, Registered Dietitian. "Some people may experience increased appetite, cravings for carbohydrates and sugary foods, and changes in how their body processes nutrients. All these factors can contribute to weight gain."

Learning the reasons why Zyprexa makes you gain weight can help you manage this side effect. They include:

1. Increased appetite

Zyprexa works on several brain chemicals that control your feelings of hunger and fullness. It can interfere with hormones like leptin, which tells your body "I'm full," and ghrelin, which signals "I'm hungry." This is why you might find yourself wanting to eat more when taking this medication.

Some research backs this up: In one study that followed people taking Zyprexa for 12 weeks, more than three-quarters of the participants noticed they were hungrier than usual. What's particularly interesting is that nearly 60% started feeling this increased hunger within just the first month of treatment.

2. Metabolic changes

Zyprexa can influence how your body processes and stores energy. Some research suggests it:

• Slows down metabolism, meaning your body burns fewer calories at rest
• Increases fat storage. In studies on mice, olanzapine increased abdominal fat storage and the size of fat cells.
• Alters glucose (blood sugar) metabolism
• Affects how lipids (fats) are processed in the body

3. Sleepiness and tiredness

Many who take Zyprexa report feeling drowsy and tired all the time. Being sedated can make it harder to stick to your exercise goals and could contribute to weight gain.

Who is most at risk for Zyprexa weight gain?

While anyone taking olanzapine may experience weight gain, certain factors can increase your risk. They include:

1. Personal risk factors

Your genes, baseline BMI (body-mass index), and starting weight may make certain individuals more prone to weight gain when taking antipsychotics like Zyprexa. A healthcare provider may help you learn how your BMI and weight may influence weight gain on Zyprexa.

2. Age and sex

Age and sex also play a role when it comes to weight gain on Zyprexa. For example, one study indicates that women over 40 years of age experienced the most weight gain on olanzapine.

3. Stage of treatment

You may notice more rapid weight gain in the initial months after you start taking Zyprexa. One study found that over 58.1% of people studied had increased appetite within the first 4 weeks. In the study, people who experienced higher hunger pangs increased their initial body weight by more than 7%.

How can you stop weight gain on Zyprexa?

While it may be hard to stop gaining weight on the drug, there are several approaches that can help minimize this side effect.

1. Work closely with your healthcare team

If you are on Zyprexa or another antipsychotic, it is very important not to stop taking your medication without your doctor’s approval and supervision. If you are concerned about weight gain and side effects, talk to your doctor about them. Based on their evaluation, they may adjust your dosage and, in some cases, add medication that can help counter weight gain. Depending on your condition, they may even switch antipsychotics.

Regular check-ins allow your provider to track weight changes and catch concerning trends early.

2. Adjust your diet

What you eat plays a vital role in managing Zyprexa-related weight gain. The first step is to create a balanced plate.

"Focus on creating balanced meals with lean proteins, fiber-rich vegetables, and complex carbohydrates," advises Rita Faycurry, RD. "This combination helps manage blood sugar levels and keeps you feeling fuller longer, potentially reducing the increased appetite associated with Zyprexa."

A balanced plate might include:

• Non-starchy vegetables (like leafy greens, broccoli, peppers)
• Lean protein (chicken and turkey breast, fish, tofu, beans and legumes)
• Smaller amounts of whole grains or starchy vegetables (brown rice, quinoa, sweet potatoes)
• A small amount of healthy fats (olive oil, avocado, nuts)

Working with a weight loss dietitian can make this process easier. 

They can help you develop personalized meal plans that account for Zyprexa's effects on your appetite and your food preferences.

4. Practice mindful eating

If you’re getting on Zyprexa, it may be a good time to examine your eating habits and see where you could make improvements. Mindful eating can help you recognize hunger and fullness cues, even when medication affects your appetite.

Here are some ways to eat more mindfully:

• Eat slowly and without distractions (try not to “zone out” during meals as relaxation. This way, you can keep track of what you eat)
• Pay attention to how the food tastes and how full you feel
• Stop eating when you feel comfortably satisfied, not stuffed. The people of Okinawa, Japan, have a saying, "hara hachi bu," which means eating until you are 80% full.
• Use smaller plates to help with portion control

5. Follow an exercise routine

Exercise is important in managing Zyprexa-related weight changes. Even small activities make a difference, such as taking short daily walks, parking farther from the entrance, or taking stairs instead of elevators wherever possible.

The US CDC recommends adults get 150 minutes of moderate-intensity activity per week (about 30 minutes, five days a week) and muscle-strengthening activities twice weekly. Adding strength training with bodyweight exercises can boost metabolism by building muscle.

Before starting any new fitness routine, it's important to discuss with your healthcare provider what exercises are suitable for your specific condition.

6. Sleep and stress management

Poor sleep habits and high-stress levels can make weight management even more challenging. Try to get 7-9 hours of quality sleep each night by sticking to a consistent schedule and creating a calming bedtime routine.

Managing your stress is equally important. Simple practices like deep breathing, gentle yoga, tai chi, or spending time in nature can make a real difference.

These might seem like small changes, but they work together with your nutrition and exercise efforts to help manage weight while supporting your overall health during treatment.

How can a dietitian help with Zyprexa weight gain?

A registered dietitian can be your best ally when managing Zyprexa-related weight changes. These experts provide guidance tailored to your unique situation.

"Managing weight on Zyprexa isn't about generic diet plans," says Faycurry, RD. "It's finding what works for you personally—addressing how the medication affects your metabolism and appetite."

Your dietitian will assess your eating patterns, nutritional needs, medication effects, food preferences, and lifestyle factors to create customized meal strategies that manage hunger and cravings.

They'll provide behavior change support, teach mindful eating, and offer strategies for challenging situations. Working with your healthcare team, they'll monitor your response to both medication and dietary changes while developing sustainable eating habits that evolve with your needs.

Frequently Asked Questions (FAQs)

Are Zyprexa and olanzapine the same?

Olanzapine and Zyprexa are the same medication; Zyprexa is simply the brand name, while olanzapine is the generic name. Your prescription might come labeled as either, depending on whether you receive the brand-name or generic version, but the active ingredient and effects are the same.

Does Zyprexa make you gain weight?

Yes, Zyprexa (olanzapine) is known to cause weight gain in many people who take it.  For example, one study shows that 34-55% of patients with normal weight gained at least 7% of their body weight during treatment. Weight gain is often related to increased appetite, metabolic changes, and alterations in how the body processes energy.

What is the average weight gain on Zyprexa?

Weight gain on Zyprexa varies significantly between individuals and depends on factors like age, sex, starting weight, and genetics. In one study, 66.6% of the people gained between 2.2 and 11 pounds in just four weeks of treatment. Additionally, women over 40 appear to be at higher risk for more significant weight gain.

How to stop gaining weight on Zyprexa?

Weight gain on Zyprexa can be challenging, but you're not powerless against it. Working with a dietitian helps create custom eating plans tailored to your needs.

Focus on balanced meals with lean proteins and veggies while practicing mindful eating. Regular exercise (both cardio and strength training) makes a significant difference. Don't forget good sleep and stress management!

Always maintain contact with your healthcare team and never stop your medication without medical guidance.

Manage Zyprexa weight gain. Find a weight loss dietitian who accepts your insurance.

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.