Does Suboxone® make you gain weight? What the research actually shows

Maybe you’ve noticed your weight has shifted since starting Suboxone® (buprenorphine-naloxone), and you’re trying to understand what’s behind it. Maybe you’ve even wondered whether Suboxone (buprenorphine-naloxone) itself could be playing a role. It’s a question that deserves more than a simple yes or no, so let’s look at what the research actually shows.

Does Suboxone make you gain weight?

Being on Suboxone (buprenorphine-naloxone) when your weight changes doesn’t mean the medication caused it.

Weight gain isn’t currently listed as an established side effect of buprenorphine-naloxone in FDA labeling or SAMHSA’s national treatment guidance. That doesn’t mean you can’t experience weight changes during treatment, but the medication itself may not necessarily be the cause.

For many people, weight changes during recovery may have more to do with the adjustments happening along the way than with Suboxone (buprenorphine-naloxone) itself. Changes in eating, other medications you’re taking, and ordinary shifts in your daily routine can all influence your weight, making it difficult to pinpoint any one cause.

We’ll discuss four factors that may contribute to weight changes, including fluid retention, constipation, appetite changes, and actual fat gain. Some of these can overlap with other effects you may experience during treatment, so it’s also helpful to learn more about the full range of Suboxone (buprenorphine-naloxone)  side effects and how to manage them.

What the research shows about weight on Suboxone

Research on weight changes with Suboxone (buprenorphine-naloxone) is limited and mixed. Overall, the evidence suggests that any average weight gain is likely modest and considerably less than what has been seen with methadone.

A clinical review identified 21 studies that measured weight during treatment for opioid use disorder. Most, 16 in total, were focused on methadone. The remaining studies looked at other medications, and several were individual case reports.

Studies involving buprenorphine have reported different results:

• One study followed 107 patients for four months and found that their average weight increased by about 10 pounds. Another study followed 360 people for 12 weeks and found almost no change in weight.

Taken together, the research does not show a strong or consistent link between Suboxone and weight gain. A small amount of weight gain over time may be possible, but more research is needed to understand how much of that change is related to the medication itself versus other factors that can affect weight during recovery.

What was studied	How many people	How long	What it found
Methadone (across the 21-study review)	16 of 21 studies	Roughly six months, varying by study	Weight gain documented, ranging from about 4 to 23 pounds, depending on the study
Buprenorphine-naloxone, inpatient cohort	107 patients	4 months	Average weight rose from about 141 to about 151 pounds
Buprenorphine, national trial reanalysis	360 patients (209 men, 151 women)	12 weeks	No significant weight change, no difference by sex
Buprenorphine vs. methadone, metabolic comparison	58 patients (26 buprenorphine, 32 methadone)	Single point in time	Similar insulin resistance in both groups; lower rates of metabolic syndrome in the buprenorphine group
FDA prescribing label	—	—	Weight gain and weight loss are not listed as adverse reactions for buprenorphine-naloxone

What this chart means: Weight gain appears to be more strongly associated with methadone. Research on buprenorphine is more limited, but one large study found a small increase in weight about 5 pounds over one year, compared with about 10 pounds for methadone.

Is it fluid, constipation, or actual weight gain?

Swelling from fluid retention, medically called peripheral edema, is a listed side effect of Suboxone (buprenorphine-naloxone). It has also been reported by patients since the medication became widely available.

However, there isn’t enough information to know how often it happens or whether Suboxone (buprenorphine-naloxone) is always the cause. And while fluid retention can make the number on the scale go up, it isn’t the same as gaining body fat.

Here are a handful of clues that can help you sort one from the other:

• Fluid tends to show up in your hands, feet, ankles, or face rather than your midsection, builds up over a matter of days, leaves a dent if you press on it, and often shifts by the next morning.
• Fat gain tends to happen slowly, spreads out rather than concentrating in one place, and doesn’t change much from morning to evening.
• Constipation can add weight of its own that resolves once it clears up.
• Muscle loss paired with fat gain can leave your total weight unchanged even though your body composition has shifted underneath it.

These general patterns can help you notice changes in your body, but they aren’t meant to help you diagnose or treat the cause on your own. If something seems unusual, bring it up with your QuickMD doctor at your next visit.

Important: Don’t take a water pill (diuretic) or an over-the-counter product for swelling without talking to your QuickMD doctor first. These products can have their own risks, even if someone you know or an online source recommends them.

Does Suboxone make you hungry?

Increased appetite (or loss of appetite) aren’t listed as official side effects of Suboxone (buprenorphine-naloxone). If you’re experiencing either, it may be connected to other physical or lifestyle shifts that can happen throughout recovery.

Opioid use suppresses the appetite. Once withdrawal eases and that effect lifts, your desire to eat can feel stronger than it did before. It’s tempting to assume that means any weight you gain during treatment is just the body recovering the weight you lost during active substance use, but it’s not the full explanation.

The clinical review referenced above found that most patients weren’t underweight when they entered treatment. Other factors may affect weight over time, too. For example, fatigue and drowsiness can occur with Suboxone (buprenorphine-naloxone) and may make it harder to stay active.

Other patients may face the opposite: anxiety, nausea, and an unsettled stomach may push your appetite down instead, which is just as common. 

Why sugar cravings feel so strong during recovery

A lot of patients are surprised when they have sudden cravings for sugar. If you’ve felt yourself wanting sweets in a way you never used to before, you’re not the only one.

A stronger preference for sweet foods has been documented during recovery from opioid use, though it hasn’t been shown to be a direct effect of buprenorphine itself. Instead, it may be connected to shifts in your mood, eating habits, routine, and what your body is used to relying on.

Here are a few adjustments that may help you curb sugar cravings:

• Anchor meals around protein and fiber so cravings have less room to take over.
• Keep sweets less accessible rather than stocked within easy reach.
• Notice whether a craving is really about stress or boredom instead of hunger. Eating for comfort is another common factor behind weight changes, right alongside diet shifts and other medications, and it isn’t something to feel guilty about; it’s just something to be mindful of.

If you’re eating more sweets, oral health is important to keep in mind, especially since Suboxone (buprenorphine-naloxone) film can also cause dry mouth. Our article on Suboxone (buprenorphine-naloxone) and oral health offers practical ways to help protect your teeth.

Can Suboxone make you lose weight?

Unintended weight loss isn’t an official side effect of Suboxone (buprenorphine-naloxone), but some patients may notice their weight drop during treatment. Research cannot point to a specific reason to claim why this happens. Nausea, an unsettled stomach, anxiety, changes in appetite, or simply eating less than usual can all affect your weight during recovery.

We know weight loss can also bring an unexpected concern: people around you mistaking it for a sign of relapse. That assumption can be stressful, especially when you’re doing well in your recovery. If you’re losing weight without trying or are concerned about how much you’ve lost, talk with your QuickMD doctor about what you’re experiencing.

What to do about weight changes on Suboxone

If a change in weight has you thinking about lowering your dose or stopping treatment, talk with your QuickMD doctor before making any changes. If your treatment is otherwise working well, your doctor can help you weigh your concerns and decide whether anything needs to be adjusted.

For many people, staying on Suboxone (buprenorphine-naloxone) can be an important part of maintaining recovery, even when concerns like weight changes come up. Instead of making changes on your own, bring these questions to your next visit:

• Could something other than my medication, like my thyroid or hormone levels, be part of what’s going on?
• Is the swelling I’ve noticed worth looking into?
• Could any of my other medications be affecting my weight?
• If we ever needed to change my treatment plan, what would that actually involve?

The ordinary stuff still helps the most: regular meals with enough protein, movement that’s comfortable for where you are in your recovery, staying hydrated, and some patience as your body adjusts to treatment and new routines. Your QuickMD doctor can discuss all of this the next time you meet. 

When weight or appetite changes need your doctor’s attention

Certain signs shouldn’t wait for your next scheduled visit. If you notice any of the following signs, reach out to book an earlier visit with your QuickMD doctor:

• New or worsening swelling in your legs, feet, hands, or face.
• Losing a significant amount of weight without trying.
• Any fast, unexplained shift in weight, in either direction.

Certain situations are more serious. Please visit the nearest emergency room or call 911 if you experience any of the following:

• An ongoing inability to eat or keep any food down.
• A sudden loss of appetite along with pain on your right side, yellowing skin or eyes, dark urine, or unusually pale stools. These are classic signs of liver trouble, which are included as a warning in the Suboxone (buprenorphine-naloxone) prescribing label.
• Ongoing nausea, vomiting, weakness, or dizziness together with a loss of appetite.

Most weight changes you experience during recovery won’t match what’s on either list. But if any of them sound familiar, reach out to your QuickMD doctor or seek emergency care right away.