Does naltrexone cause weight gain?
Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on April 6, 2021.
- Weight gain is not a common side effect with oral naltrexone treatment. Naltrexone is approved to help promote weight loss when used in combination with bupropion (brand name: Contrave).
- Naltrexone is known to frequently cause stomach side effects like nausea and vomiting (10% or more of patients), stomach pain or cramping, and loss of appetite which could contribute to weight loss. These side effects may lessen over time.
- Oral naltrexone has been reported by the manufacturer to cause both weight gain and increased appetite, but these are not frequent adverse events.
Naltrexone when combined with bupropion (brand name: Contrave) is used to help with weight loss. Contrave is an extended-release form of two FDA-approved drugs, oral naltrexone tablets and oral bupropion (Wellbutrin SR).
Contrave is used in obese or overweight adults with at least one weight-related condition such as high blood pressure or type 2 diabetes. It is used in addition to diet and exercise. In clinical trials, 36% to 48% of patients taking Contrave lost at least 5% of body weight.
Naltrexone is an opioid antagonist approved to treat alcohol or opioid dependence (following detoxification) along with group counseling. Bupropion is classified as an antidepressant and is used to treat depression, seasonal affective disorder and as an aid to quit smoking.
- Naltrexone prescribing information. Major Pharmaceuticals. Last updated May 1, 2020. Accessed April 6, 2021 at https://www.drugs.com/pro/naltrexone.html
- Contrave (bupropion and naltrexone) prescribing information. Currax Pharmaceuticals. Last updated March 1, 2021. Accessed April 6, 2021 at https://www.drugs.com/pro/contrave.html
Related Medical Questions
- What happens if you drink alcohol while taking naltrexone?
- Can you drink alcohol on Vivitrol or will you get sick?
- Should I take naltrexone in the morning or at night?
- How long does Vivitrol last in your system?
- What to avoid when taking naltrexone?
- How long does naltrexone take to work?
- What's the difference between naltrexone and naloxone?
- What happens if you take opiates while on Vivitrol?
- Is naltrexone a controlled substance?
- Does naltrexone make you sleepy?
- Does naltrexone block endorphins?