
When taken as prescribed, Suboxone should not make you sick.
Suboxone (buprenorphine/naloxone) is a prescription medication designed to help treat opioid use disorder (OUD), and it is very effective and safe.
While Suboxone can cause side effects some people find unpleasant, it shouldn’t make you ill when taken properly.
However, if you take Suboxone too soon after using opioids, you can experience what is called “precipitated withdrawal,” which can make you feel sick for a few hours or days.
If you feel sick after taking buprenorphine/naloxone (Suboxone), it’s most likely due to taking the medicine too soon after using opioids like heroin, fentanyl, oxycodone, or hydrocodone. Taking Suboxone too soon after taking an opioid can cause precipitated withdrawal, which can feel like the flu. You may mistake your withdrawal symptoms for Suboxone side effects.
If you feel sick after taking Suboxone, it’s most likely due to taking the medicine too soon after using opioids.
During precipitated withdrawal, any active opioid within your body is removed from receptors and replaced by Suboxone. In essence, your body is deprived of the drugs it thinks it needs to feel normal and calm, and this sends you into full-blown opioid withdrawal.
Issues like this are most common in people who use long-acting opioids, like methadone or morphine.[1] But it can happen to anyone who uses Suboxone too soon after using an opioid, including people who misuse fentanyl.[2]
Precipitated withdrawal symptoms include the following:[1]
Symptoms tend to begin within an hour or two of your first Suboxone dose and last for about 24 hours.[1]
To avoid any precipitated withdrawal when first starting Suboxone, wait about 12-24 hours after your last opioid, or when you begin to feel the natural symptoms of opioid withdrawal. [3] You should talk with your doctor about timing before starting Suboxone to ensure you don’t take your Medication for Addiction Treatment (MAT) too early.
To avoid precipitated withdrawal, wait about 12-24 hours after you last used an opioid before starting Suboxone.
Like any medication, buprenorphine/naloxone (Suboxone) has side effects. Most are relatively mild and can be managed under close medical supervision, sometimes with relief from over-the-counter (OTC) medications.
Suboxone’s most common side effects that you may mistake for feeling sick include the following:[4]
You may not experience any side effects at all. But if you do, they’re most common in the first few days of treatment. They may subside as your body adapts to the new medication.
Before you take your first Suboxone dose, talk to your doctor. Ask about the side effects you should expect, and learn what to do if you feel ill or feel worse while using your medication. Your doctor may offer some good advice you can use to feel better.
If your symptoms are severe or don’t get better with time, tell your doctor, who will work with you over the first few days and weeks of your therapy to ensure you are tolerating the medication well and adjusting your dose properly.
Other ways to manage the side effects of Suboxone or deal with precipitated withdrawal symptoms include:
At the end of the day, you shouldn’t feel worse than before when you take Suboxone, which is meant to help you achieve and maintain abstinence and improve your life. If you find that you’re unable to tolerate Suboxone, talk to your doctor about lowering your dose or switching to a different medication like Sublocade, naltrexone, or methadone.

Peter Manza, PhD received his BA in Psychology and Biology from the University of Rochester and his PhD in Integrative Neuroscience at Stony Brook University. He is currently working as a research scientist in Washington, DC. His research focuses on the role of the brain dopamine system in substance use disorders and in aging. He also studies brain function in obesity and eating disorders.
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