Contrave: Side effects and how to manage them

Contrave (naltrexone/bupropion) is one of the prescription weight-loss medications that can help some adults lose weight and keep it off when paired with a lower-calorie diet and more physical activity. For many people, it can be a real game-changer. For others, it can feel more like, “I signed up for weight loss, not this side-effect roller coaster.”

If you are starting Contrave, already taking it, or just researching your options, understanding its side effects and how to manage them is crucial. This guide walks you through the most common and serious side effects, who is at higher risk, and practical strategies to feel as well as possible while working toward your weight-loss goals.

Important disclaimer: This article is for general education only and does not replace medical advice from your own healthcare professional. Always talk with your prescriber or pharmacist about your specific situation.

What is Contrave, exactly?

Contrave is a combination of two medications:

• Naltrexone – an opioid receptor blocker often used to treat alcohol or opioid use disorder.
• Bupropion – an antidepressant and smoking-cessation medication (you may recognize the brand name Wellbutrin or Zyban).

Together, in extended-release form, they work on areas of the brain involved in appetite and reward. In simple terms, Contrave is designed to help reduce cravings and curb overeating. It’s not magic, and it still requires lifestyle changes, but it can be a helpful tool in a broader weight-management plan.

Like every medication, though, it comes with a side-effect profile you should know about before you swallow that first pill.

Common Contrave side effects (the not-so-fun but usually manageable stuff)

Most people who take Contrave experience at least some mild side effects, especially in the first few weeks. The most commonly reported include:

• Nausea and sometimes vomiting
• Constipation or, less often, diarrhea
• Headache
• Dizziness
• Trouble sleeping (insomnia)
• Dry mouth
• Fatigue or feeling “off” while your body adjusts
• Changes in the way food tastes

The good news: many of these side effects improve as your body gets used to the medication, especially if the dose is increased slowly as prescribed. The less-good news: the first few weeks can still be rough. Let’s break down the big ones and talk about what you can do.

Nausea, vomiting, and stomach upset

Nausea is probably the number one complaint. Some people feel mildly queasy; others feel like they’re on a boat during a storm.

What it feels like

You might notice loss of appetite, queasiness when you look at food, or nausea shortly after taking your dose. Occasionally, people also have vomiting or cramping.

Tips to manage nausea

• Take Contrave with food (unless your prescriber says otherwise). A small meal or snack, not an empty stomach, is usually easier to tolerate.
• Avoid heavy, greasy meals when you take your dose. Think toast with peanut butter rather than a double cheeseburger.
• Split your fluids – take small sips of water, ginger tea, or electrolyte drinks throughout the day instead of chugging large amounts at once.
• Try bland foods like crackers, rice, bananas, or applesauce when your stomach is unsettled.
• Ask your prescriber if a short-term anti-nausea medication is appropriate for you, especially in the first few weeks.

If vomiting is frequent, persistent, or you can’t keep fluids down, that is a “call your healthcare team promptly” situation.

Constipation

Contrave can slow your gut a bit, and the changes in appetite and food intake can add to the problem. Constipation may show up as fewer bowel movements, straining, or hard stools.

Tips to manage constipation

• Hydrate like it’s your job. Aim for steady fluid intake throughout the day unless you’re on a fluid restriction.
• Add fiber gradually. Oats, beans, fruits with skin, vegetables, and whole grains can helpbut increase slowly to avoid extra gas and bloating.
• Move your body. Walking, light exercise, and even simple stretching can help your gut move too.
• Talk with your provider about a stool softener or gentle laxative if lifestyle changes aren’t enough.

Headache

Headaches can be mild or more intense. Sometimes they show up as your body adjusts to changes in appetite, hydration, sleep, or blood pressure.

Tips to manage headache

• Stay well-hydrated and don’t skip meals entirely unless your prescriber has given you a structured fasting plan.
• Limit caffeine swingsgoing from “five coffees a day” to “none” overnight can cause withdrawal headaches.
• Ask your healthcare professional if you can use over-the-counter pain relievers like acetaminophen or ibuprofen and how often.
• If headaches are severe, sudden, or come with vision changes, chest pain, or shortness of breath, seek medical care right away.

Insomnia and weird sleep patterns

The bupropion component can be stimulating. Some people feel more alert or restless and find it harder to falland stayasleep.

Tips to manage insomnia

• Follow your prescriber’s directions about not taking doses too close to bedtime. Evening doses are usually earlier in the evening, not at midnight.
• Practice good sleep hygiene: regular bedtime, no doom-scrolling in bed, a cool dark room, and a wind-down routine.
• Limit caffeine, especially after lunch, so you’re not stacking stimulants on top of bupropion.
• If insomnia is severe or persistent, let your prescriber knowsometimes dose timing or other medications can be adjusted.

Dizziness and feeling “off”

Dizziness, lightheadedness, or feeling “spacey” can occur, especially when you first start Contrave or when the dose is increased.

Tips to manage dizziness

• Stand up slowly from sitting or lying down.
• Avoid driving or operating heavy machinery until you know how Contrave affects you.
• Make sure you are eating and drinking regularly so low blood sugar or dehydration aren’t making things worse.

Dry mouth and taste changes

Dry mouth can be annoying, and some people notice food tastes different or less appealing.

Tips to manage dry mouth

• Sip water or sugar-free drinks throughout the day.
• Chew sugar-free gum or suck on sugar-free lozenges to stimulate saliva.
• Practice good oral hygiene and see your dentist regularlydry mouth can increase cavity risk.

Serious Contrave side effects you should never ignore

Most people do not experience serious side effects, but Contrave does carry important warnings, including a boxed warning related to mood and behavior. You need to know what to watch for.

Seizures

Bupropion can lower the seizure threshold, meaning seizures are more likely in people who already have risk factors. Contrave is not recommended for people with a seizure disorder or certain other conditions that raise seizure risk, such as a history of certain eating disorders or abrupt withdrawal from alcohol or benzodiazepines.

Call emergency services right away if someone taking Contrave has a seizure, collapses, or is unresponsive.

Suicidal thoughts, mood changes, and mental health shifts

Medications containing bupropion can, in some peopleespecially younger adultsbe associated with new or worsening depression, suicidal thoughts, or unusual behavior changes. These effects tend to be more likely when the medication is first started or when the dose changes.

Contact a healthcare professional immediately (and seek emergency help if needed) if you or someone close to you notices:

• New or worsening depression or anxiety
• Suicidal thoughts or talk about self-harm
• Agitation, irritability, or extreme mood swings
• Behavior that seems out of character or dangerous

Blood pressure and heart rate changes

Contrave can increase blood pressure and heart rate. For people with normal blood pressure, this may not be a big issue. For people with uncontrolled hypertension or certain heart conditions, it can be risky.

What to do

• Make sure your blood pressure is checked before starting Contrave.
• Monitor it regularly at home if your prescriber recommends it.
• Report symptoms such as severe headache, chest pain, shortness of breath, or pounding heartbeat.

Liver problems

Both naltrexone and bupropion can rarely affect the liver. Watch for signs such as:

• Yellowing of the eyes or skin (jaundice)
• Dark urine and pale stools
• Persistent right upper abdominal pain
• Severe fatigue, nausea, or loss of appetite

If you notice these, contact your healthcare professional promptly.

Allergic reactions and eye problems

Serious allergic reactions are rare but possible. Seek emergency care if you develop:

• Swelling of the face, lips, tongue, or throat
• Trouble breathing or wheezing
• Severe rash or hives

Sudden eye pain, vision changes, or seeing halos around lights could be signs of an eye emergency such as angle-closure glaucoma. Get immediate medical attention if this happens.

Low blood sugar in people with diabetes

Contrave itself does not lower blood sugar, but weight loss and other medications (like insulin or sulfonylureas) can. If you have type 2 diabetes and take medications that lower blood sugar, your prescriber may adjust your doses and ask you to monitor your blood sugar more closely to avoid hypoglycemia.

Who is at higher risk of side effects?

Contrave may not be appropriateor needs extra cautionin people who:

• Have a current or past seizure disorder
• Have a history of anorexia or bulimia
• Have uncontrolled high blood pressure
• Use opioid medicines or are going through recent opioid withdrawal
• Drink heavily or are stopping alcohol or certain sedatives abruptly
• Have significant liver disease
• Are pregnant or planning pregnancy (Contrave is not recommended in pregnancy)

This is not a complete list, which is why an honest conversation with your prescriber about your full medical history and all your medications (including supplements) is essential before starting Contrave.

Practical tips for managing Contrave side effects day to day

You and your healthcare professional are a team. These strategies can make that teamwork more effective:

1. Respect the titration schedule

Contrave is usually started at a low dose and gradually increased over several weeks. This slow build allows your body to adjust and often reduces side effects. Taking “extra” or jumping ahead on the schedule is a great way to feel miserable and a bad way to lose weight faster.

2. Keep a simple symptom journal

Jot down when you take doses, what you eat, and how you feel. Patterns often emergemaybe nausea is worst on days you skip breakfast, or headaches show up when you drink less water. Those clues help you and your prescriber tweak your plan.

3. Focus on gentle, sustainable lifestyle habits

• Nutrition: Aim for balanced meals with protein, fiber, and healthy fats rather than surviving on coffee and vibes.
• Movement: Even short walks can help with constipation, mood, and sleep.
• Sleep: Give yourself enough hours in bed and consistent bed/wake times.

4. Communicate early, not only when it’s an emergency

Don’t wait until you are ready to quit the medication in frustration. Reach out if:

• Side effects are not easing after a few weeks
• You’re skipping doses because of how you feel
• You’re unsure which symptoms are normal and which are red flags

Your prescriber may adjust the dose, change timing, add supportive medications, or consider alternative options.

When to call your doctor vs. when to call 911

Call your doctor or clinic promptly if you notice:

• Persistent nausea, vomiting, or constipation that doesn’t improve with home measures
• Mild to moderate headaches that keep returning
• Ongoing insomnia, restlessness, or anxiety
• Worsening blood pressure readings (if you monitor at home)
• Early mood or behavior changes that concern you but are not an immediate crisis

Call emergency services (911 in the U.S.) or go to the ER if you have:

• Seizure or loss of consciousness
• Thoughts of harming yourself or others
• Chest pain, severe shortness of breath, or sudden severe headache
• Signs of a severe allergic reaction (trouble breathing, facial or throat swelling)
• Sudden vision loss or severe eye pain

Real-world experiences: what Contrave side effects feel like in everyday life

Numbers and bullet points are important, but they don’t always capture what living with Contrave side effects actually feels like. While every person’s experience is different, many stories follow a similar arc: a rocky start, an adjustment period, and then a decision about whether the benefits outweigh the downsides.

Example 1: “The queasy first month.” Imagine someone starting Contrave with high motivation. The first week goes wellmaybe a little dry mouth, but nothing major. By week two, as the dose increases, nausea kicks in hard. Breakfast sounds awful; dinner isn’t much better. They notice they’re losing weight but also spending a lot of time hugging a ginger ale.

Working closely with their prescriber, they tweak the timing of doses, take each dose with a small meal, and add a short-term anti-nausea medicine. Hydration and small, frequent meals become the new normal. By week five or six, the nausea has faded to mild queasiness a few times per week, and they can focus more on their nutrition and activity goals. For this person, the rough start eventually settles into a manageable routine.

Example 2: “The sleep struggle.” Another person feels relatively fine during the day but can’t fall asleep once they start Contrave. They toss and turn, wake up multiple times at night, and feel tired and irritable during the day. Their evening dose is at 9 p.m., right before bed.

After talking with their prescriber, they shift the evening dose earlier and make changes to their bedtime routineless screen time, no late caffeine, and a consistent wind-down period. Over the next few weeks, their sleep improves. For them, managing Contrave side effects was less about nausea and more about respecting how stimulating bupropion can be.

Example 3: “I realized it wasn’t for me.” For some, side effects simply don’t let up. Maybe headaches remain frequent and severe, mood feels off, or blood pressure creeps up despite adjustments. With their healthcare professional, they weigh the pros and cons: yes, there’s some weight loss, but overall quality of life is worse.

In that case, the best decision may be to stop Contrave safely (always under medical supervision) and explore other optionswhether that’s a different medication, bariatric surgery, or a non-pharmacologic approach. Deciding that Contrave isn’t the right fit is not a failure; it’s part of tailoring treatment to the individual.

What these stories have in common:

• Monitoring and communication make a big difference. Keeping track of symptoms helps your healthcare team help you.
• Side effects are highly individual. One person’s minor annoyance is another person’s deal-breaker.
• Your comfort and safety matter. Weight loss is important for health, but it should not come at the cost of ignoring serious mental or physical side effects.

Hearing experiences from otherswhether in a support group, online community, or healthcare settingcan be reassuring. You’re not the only one figuring out how Contrave fits into your life, and it’s okay to ask questions, set boundaries, and advocate for yourself.

The bottom line

Contrave can be an effective tool for weight management in adults living with overweight or obesity, but it brings a real side-effect profile along for the ride. Common issues like nausea, constipation, headache, insomnia, dizziness, and dry mouth are often manageable with time, dose adjustments, and practical strategies. More serious effectssuch as seizures, mood changes, blood pressure increases, liver problems, and allergic reactionsrequire careful monitoring and prompt medical attention.

If you are considering Contrave, the key is partnership: you, your prescriber, and sometimes your pharmacist working together. Ask questions, share your concerns, and be honest about how you feel on the medication. Weight loss is not just about numbers on a scale; it’s about protecting your overall health, both physical and mental, along the way.