Most Contrave side effects are temporary, lasting anywhere from a few days to a few weeks. They tend to be most noticeable during the first few weeks of treatment or right after a dosage increase. Because Contrave is started at a low dose and gradually increased over four weeks, side effects often flare at each step up before your body adjusts.
The Most Common Side Effects
Nausea is the side effect people notice first and complain about most. It frequently appears within the first week of starting Contrave and can return or intensify each time the dose increases. Other common early side effects include constipation, headache, vomiting, dizziness, trouble sleeping, dry mouth, and diarrhea.
For most people, these symptoms peak during the first two to four weeks, which is exactly the period when the dose is being ramped up. Once you reach the full dose and stay on it for a couple of weeks, your body typically adapts and the intensity drops significantly. Some people find nausea resolves within days at each new dose level, while others deal with it on and off for several weeks before it fades.
Why the First Month Is the Hardest
Contrave is prescribed on a four-week escalation schedule specifically to reduce side effects. During week one, you take just one tablet in the morning. Week two adds a second tablet in the evening. Week three bumps the morning dose to two tablets while keeping one in the evening. By week four, you reach the full dose of two tablets twice daily.
Each step introduces more of the medication into your system, which is why side effects can seem to come in waves. You might feel fine during week one, then get hit with nausea again when the evening dose starts in week two, and so on. This pattern is normal and part of the adjustment process. The gradual increase also helps reduce the risk of seizure, which is a rare but serious concern with one of Contrave’s active ingredients.
What Helps While You Adjust
Taking Contrave with food is the simplest and most effective way to reduce nausea. The medication is designed to be taken alongside a meal, not on an empty stomach. Skipping this step is one of the most common reasons people feel worse than they need to during the adjustment period.
Beyond timing your dose with meals, staying hydrated and eating smaller, more frequent meals throughout the day can ease digestive discomfort. If constipation becomes an issue, increasing fiber and water intake often helps. For insomnia, taking the evening dose earlier (but still with food) may make a difference, since one of Contrave’s components is a stimulating antidepressant that can interfere with sleep if taken too close to bedtime.
Side Effects That Need Attention
Most Contrave side effects are uncomfortable but not dangerous. A smaller number of effects, however, deserve prompt attention. Contrave carries a boxed warning about the potential for changes in mood, including new or worsening depression, anxiety, irritability, agitation, and suicidal thoughts. These risks are linked to the bupropion component, which is also used as an antidepressant. Pooled analyses of clinical trial data show that patients were actively monitored for increases in sadness, irritability, anxiety, and suicidal thinking throughout treatment.
These mood-related effects are not the same as feeling a little “off” during the first week. If you notice a distinct shift in your mental state, persistent dark thoughts, or feelings that are clearly out of character, that is a signal to contact your prescriber right away rather than waiting to see if it passes.
Seizures are another rare but serious risk. The chance is lower when you follow the dose escalation schedule, never take more than two tablets at once, and stay within the recommended total of four tablets per day. People with a history of seizures, eating disorders, or alcohol withdrawal are at higher risk.
When Side Effects Don’t Fade
If nausea, headaches, or other common symptoms persist well beyond the first month at full dose, that is longer than typical. Some people find that certain effects like dry mouth or mild constipation stick around for as long as they take the medication, but these tend to be manageable. Persistent nausea past the six- to eight-week mark, or side effects that interfere with daily life, suggest the medication may not be a good fit.
Your prescriber may recommend temporarily dropping back to a lower dose and re-escalating more slowly. In some cases, staying at a slightly lower dose long-term reduces side effects while still providing weight-loss benefit. Not everyone needs to reach the full four-tablet daily dose to see results.
If you stop Contrave abruptly, some rebound effects (particularly changes in appetite or mood) can occur, so tapering under guidance is generally preferred over stopping cold.