Does Subutex Cause Weight Changes?

Subutex is a medication for opioid use disorder that is not known to directly cause weight gain or weight loss. However, some of its side effects may cause changes in weight in some people. Subutex is a central nervous system depressant that binds to opioid receptors in the brain that help regulate physical movement, hormones, and mood.

Effects on these important functions can factor into a person’s dietary habits, physical activity, and physiology.

Learn more about the benefits of taking Subutex during medication-assisted treatment

What Causes Weight Gain While Taking Subutex?

Subutex, the brand name for buprenorphine, is not known to cause weight gain. Yet people may gain weight while taking Subutex for a number of reasons.

Weight gain while taking Subutex may or may not be directly tied to the use of the drug itself.

Constipation

Constipation is a common side effect of opioid drugs. Although Subutex is only an opioid partial agonist, meaning it has weaker effects than most other opioids, constipation can still occur. Temporary weight gain and bloating is common in people who become constipated. This doesn’t necessarily indicate permanent weight gain, but it can have harmful effects on the body if it persists without relief.

Fluid Retention

People who are taking Subutex may experience fluid retention. Peripheral edema, which refers to a swelling of the legs or feet, can also occur while taking Subutex. Water retention from Subutex may lead to minor changes in weight. It can also cause bloating or swelling. Moderate to severe swelling and edema can also be a sign of an adverse reaction to Subutex.

Changes In Appetite

Increased appetite is not a common side effect of Subutex. However, this can occur in people who are receiving treatment for opioid addiction. Decreased appetite, malnutrition, and weight loss is a common consequence of chronic drug addiction, including addiction to opioids like heroin. During the recovery process, it’s normal for a person’s appetite to return and for their weight to restore. Rather than a negative side effect, this can be a sign of improved health and nutrition.

Fatigue

Subutex has weak depressant effects on the central nervous system. After taking Subutex, a person may feel drowsy or fatigued. People who feel fatigued may be less likely to engage in physical activity. Fatigue is also associated with both a loss of appetite and increased appetite. Changes in appetite from fatigue may be influenced by underlying health conditions and other individual factors related to a person’s health and environment.

Insomnia

Difficulty falling or staying asleep is a common struggle of people who take Subutex and other medications for opioid use disorder, such as methadone and Suboxone. Research shows that sleep deprivation may have effects on neurotransmitters in the brain that help regulate the body’s hormonal system and appetite. Insomnia has been associated with increased hunger, metabolic dysregulation, and glucose intolerance—a precursor to diabetes.

Does Subutex Cause Weight Loss?

Weight loss while taking Subutex is not common, but this could potentially occur as a result of adverse side effects of Subutex or contributing causes unrelated to drug use.

Side effects and factors that can influence weight loss include:

• nausea
• vomiting
• stomach pain
• depression
• anxiety
• fatigue
• drug misuse

For some people, weight loss may occur as a result of improved diet, physical activity, or other improved clinical markers while receiving treatment for opioid addiction.

What To Know About Subutex And Effects On Weight

First of all, Subutex alone is not associated with any significant changes in weight. Weight gain or loss while taking Subutex is likely related to other personal factors. Some side effects of Subutex, such as insomnia and fatigue, may affect a person’s appetite, metabolism, and weight. Beginning the road to recovery from substance abuse or drug addiction can also have these effects. In these instances, changes in weight may be a sign of improved health, rather than a cause for concern.

Managing Weight Changes While On Subutex

If you notice weight changes while taking Subutex, there are steps you can take to manage them and stay healthy during recovery. Start by tracking what you eat and drinking plenty of water throughout the day, as this can help with both constipation and fluid retention. Regular physical activity, even just walking for 20 to 30 minutes daily, can help regulate your appetite, improve sleep, and maintain a healthy weight. If fatigue makes exercise difficult, start small and gradually increase activity as your energy improves.

Talk to your doctor if you experience significant weight gain or loss while on Subutex, especially if it’s accompanied by severe swelling, persistent constipation, or other concerning symptoms. Your healthcare provider can help determine whether the weight change is related to the medication, recovery process, or another underlying health issue.

Find Subutex Treatment For Opioid Addiction Today

For more information about the side effects of Subutex, or how to find medication-assisted treatment for yourself or a loved one, browse our directory or reach out to the Substance Abuse and Mental Health Services Administration (SAMHSA).

Written by the Addiction Resource Editorial Staff