Most of what you will feel in the first two weeks is not the medication. It is your body finding a level after a long period without one.
That is the single most useful thing to know before you start, because it explains why the early days feel worse than the months that follow, and why people who quit Suboxone in week one almost always quit for a reason that would have resolved by week three.
Suboxone is a prescription medication used to treat opioid use disorder, and this chapter covers the common side effects with the actual trial numbers attached, the serious ones that need a phone call, the dental issue the FDA has warned about, and how to tell a side effect apart from withdrawal. It sits under the guide to medication-assisted treatment. It contains no dosage information, because that belongs with your prescriber.
Why Suboxone Side Effects Occur at All
Suboxone is buprenorphine and naloxone. The Buprenorphine part is a partial opioid agonist, which means it activates the same opioid receptors that heroin and prescription opioids activate, but only partially. SAMHSA’s clinical guidance puts the mechanism plainly: “A partial agonist has a ceiling effect. Its opioid effects increase as the dose increases, but only up to a certain point” [1].
Because Suboxone occupies the same opioid receptors as other opioids in order to treat opioid use disorder, it produces some of the same unwanted effects. When you take Suboxone, constipation, sweating and drowsiness are opioid effects rather than Suboxone-specific ones. What it does not produce, at a stable prescribed dose, is the euphoric effects a full agonist delivers.
The naloxone component is an opioid antagonist included to deter drug abuse by injection. Taken as directed, it is barely absorbed and contributes very little to how you feel. Buprenorphine does produce physical dependence, which is a separate thing from a side effect and is covered in its own chapter.
Common Side Effects of Suboxone, With the Actual Numbers
Most articles on Suboxone side effects give you a list with no sense of how likely anything is. The FDA label reports rates from a four-week comparative study, which is more useful.
What the Trial Data Shows
Side effects reported by five percent or more of people taking Suboxone sublingual film in that study [2]:
- Headache, 36.4 percent
- Withdrawal syndrome, 25.2 percent
- Pain, 22.4 percent
- Nausea, 15.0 percent
- Insomnia, 14.0 percent
- Sweating, 14.0 percent
- Constipation, 12.1 percent
- Reported by more than one percent: blurred vision, palpitations, vomiting and disturbance in attention
Two things stand out. Headache is far and away the most common of the side effects of Suboxone, and it is the one people are least warned about. And withdrawal syndrome appears on a list of side effects, which is confusing enough that it gets its own section below.
The Mouth Symptoms Nobody Warns You About
Because the sublingual film dissolves under the tongue, it produces a cluster of mouth effects that surprise people. The FDA label lists oral hypoesthesia as the most common adverse reaction with sublingual administration, along with glossodynia and oral mucosal erythema [2].
In plain English: numbness in the mouth, a sore or burning tongue, and redness where the film sits. None of it is dangerous. All of it is worth knowing in advance, because a numb mouth on day one feels alarming if nobody mentioned it.
Does Suboxone Cause Constipation?
Yes, in about one person in eight during the first month [2], and it tends to persist rather than fade. Constipation pain is one of the more common reasons people quietly stop taking a medication that is otherwise working.
It is manageable, and it is worth raising early rather than enduring. Suboxone dosage is not usually the lever that fixes it. Water, fiber, and movement help, and there are side effects that respond better to a small change than to a change of medication. Your prescriber can suggest more.
Side Effects Versus Withdrawal Symptoms
This is the distinction that causes the most trouble in the first weeks, and it explains the odd trial finding above.
Headache, nausea, muscle aches, sweating, insomnia, and difficulty concentrating are all opioid withdrawal symptoms. Every one of those withdrawal symptoms is also a listed side effect of Suboxone. So when you feel rough on day three, there is no way to tell from the symptoms alone whether the medication is causing it or whether you are still coming off what you were using.
The practical test is time. Opioid withdrawal eases over the first two weeks as your body adjusts, so anything that fades on that schedule was withdrawal rather than the medication. Side effects that appear once you are stable, or that get worse rather than better, are more likely the medication. Your prescriber can act on that pattern, which is why it is worth writing down what you feel and when rather than reporting it from memory.
The Suboxone withdrawal symptoms chapter deals with coming off the medication later, which is a separate question.
What Happens in the First Two Weeks When You Take Suboxone
A rough shape of what people report when they first take Suboxone, not a schedule, because people vary more than any timeline suggests.
The first few days are usually the worst of it, and precipitated withdrawal is the specific risk. Starting Suboxone while other opioids are still active can trigger abrupt, severe withdrawal, which is why induction timing is decided by a prescriber and not guessed at. After that, the first week tends to bring headache, poor sleep, and low energy while everything settles. Where withdrawal management needs handling first, that is what medical detox is for.
Weeks two to four are where most people notice the change. The withdrawal-type symptoms fade, sleep improves, and what is left is the shorter list of genuine side effects when you take Suboxone daily: constipation, some sweating, the mouth effects. As the body adjusts, most of what remains is manageable. If you are still feeling wrong at week four, that is information rather than failure, and it is a conversation about the treatment plan rather than a reason to stop.
Serious Side Effects That Need Immediate Medical Attention
These serious side effects are uncommon, and rarer still than the risks of untreated opioid use disorder. They are also the reason this page exists rather than a list of mild complaints. Any of the following is a call now, not a wait-and-see.
Trouble Breathing and Respiratory Depression
The FDA label is unambiguous: “Life-threatening respiratory depression and death have occurred in association with buprenorphine use” [2]. Trouble breathing, breathing that is slow or shallow, or extreme drowsiness that cannot be roused is an emergency treatment situation.
Risk is higher for people with existing breathing problems, including chronic obstructive pulmonary disease and sleep apnea. Sleep-related breathing problems are worth mentioning to a prescriber before starting rather than after.
Signs of an Allergic Reaction
Serious allergic reactions are rare but documented. The label records hypersensitivity cases presenting as “bronchospasm, angioneurotic edema, and anaphylactic shock” [2].
In practice, that means a rash or hives, swelling of the face, lips, or throat, or wheezing and tightness in the chest. An allergic reaction of that kind needs immediate medical attention.
Liver Problems
The label notes that “cases of cytolytic hepatitis and hepatitis with jaundice have been observed,” and recommends baseline and periodic liver function testing during treatment [2].
Signs worth reporting straight away: dark urine, yellowing of the skin or eyes, pale stools, pain in the upper right abdomen, or unusual fatigue. Dark urine alongside any of the others is the combination that should prompt a same-day call, because these are serious unwanted effects rather than nuisances. Blood tests are how this gets caught early, which is a good reason to keep the appointments even when you feel fine.
Low Blood Pressure When You Stand Up
Suboxone “may produce orthostatic hypotension in ambulatory patients” [2], which is low blood pressure on standing. It shows up as dizziness or lightheadedness when you get up quickly.
The fix is usually simple: move from a lying or sitting position slowly. If it comes with fainting or does not settle, it needs review, because blood pressure that drops that far is worth investigating rather than working around.
The Dental Problem, and the Rinse That Prevents It
This one is specific to medicines that dissolve in the mouth, and it is under-discussed.
In 2022, the FDA warned that dental problems have been reported with buprenorphine medicines dissolved in the mouth, including tooth decay, cavities, oral infections, and tooth loss. It identified 305 cases, 131 of them serious, since the 2002 approval, with a median of around two years of use before diagnosis. Twenty-six of those cases involved people with no prior dental history at all [3]. The prescribing label carries the same warning, noting cases of dental caries severe enough to cause tooth fracture and tooth loss [2].
The prevention is easy, and it works. After the film has dissolved completely, rinse your mouth with water and wait at least an hour before brushing. Schedule regular dental checkups, starting soon after you begin treatment [3].
What the FDA explicitly does not advise is stopping. Its instruction is to “Continue taking your buprenorphine medicine as prescribed; do not suddenly stop taking it without first talking to your health care professional,” because stopping abruptly risks withdrawal, relapse, overdose, and death [3]. A rinse and a dentist is the right response to this. Quitting is not.
Long-Term Side Effects of Suboxone
The honest answer is that the long-term side effects picture is reassuring compared with the alternative, with two things worth monitoring.
Adrenal Insufficiency
The label notes that “cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use” [2]. It is uncommon, and it is treatable, usually with corticosteroid replacement.
What makes it easy to miss is how ordinary the symptoms sound: unusual fatigue, weakness, nausea, poor appetite, dizziness. If you have been stable for months and then start feeling persistently exhausted, that is worth a blood test rather than an assumption.
Mood, Sleep and Sexual Side Effects
Reduced sexual desire is reported with long-term opioid use, including buprenorphine, and so are sleep disturbances and difficulty concentrating. These are the side effects people are least likely to raise and most likely to stop a medication over.
They are worth naming out loud with a medical doctor. Some are dose-related, some resolve, and some turn out to be untreated depression rather than the medication, which is a different and very treatable problem. Where a mental health condition sits underneath, dual diagnosis treatment is the piece that has been missing.
Dangerous Interactions to Tell Medical Professionals About
Most of the genuine danger with Suboxone is not the medication alone. It is Suboxone plus something else, which is why medical professionals ask for a full list of other medicines rather than just the interesting ones.
Benzodiazepines and Central Nervous System Depressants
This is the most important interaction on the page. The FDA label states that “concomitant use of buprenorphine and benzodiazepines or other CNS depressants increases the risk of adverse reactions including overdose and death,” and directs prescribers to warn patients about self-administering them [2].
Central nervous system depressants include benzodiazepines, alcohol, sleeping tablets, muscle relaxants, and some antihistamines. Combining Suboxone with any of them is where life-threatening outcomes actually come from. This is not a reason to hide a benzodiazepine prescription from your prescriber. It is the reason to tell them.
Serotonin Syndrome
The label records “cases of serotonin syndrome, a potentially life-threatening condition” during concurrent use of opioids with serotonergic drugs, and says to discontinue if it is suspected [2]. That matters because a lot of people on Suboxone are also on an antidepressant.
Signs include agitation, confusion, a racing heart, muscle twitching, heavy sweating, and a high temperature. It is uncommon, and it is one more reason the prescriber needs the full list of what you take.
That list should include herbal or vitamin supplements. People routinely leave those off, and some genuinely interact. Certain medicines that seem harmless are the ones that cause problems precisely because nobody mentioned them, so give medical professionals the whole list and let them decide what matters.
If You Are Pregnant or Might Become Pregnant
Buprenorphine is used in pregnancy, and treating opioid use disorder is generally safer for both people than leaving opioid dependence untreated. There is one expected outcome to plan for.
The label describes neonatal opioid withdrawal syndrome as “an expected and treatable outcome of prolonged use of opioids during pregnancy,” and instructs providers to observe newborns for signs of it and manage accordingly [2]. Expected and treatable are the operative words. It is planned for, not stumbled into, and it is not a reason to stop treatment while pregnant.
This is a conversation to have early with both a prescriber and an obstetric team.
What Is the 3 Day Rule for Suboxone?
This question means two different things, and both answers are useful.
The regulatory one is real. Federal rules allow a practitioner who is not a registered narcotic treatment program to dispense a narcotic to relieve acute withdrawal while arranging referral to treatment, and “not more than a three-day supply of such medication may be dispensed” [4]. It is a bridge, not a course of treatment, and it exists so somebody in withdrawal in an emergency department is not simply sent home.
The clinical one is what most people mean, and it is a misunderstanding worth clearing up. There is no fixed three-day wait before starting Suboxone. The timing depends on which opioid you used, how long-acting it was, and whether withdrawal has actually started, because starting too early is what causes precipitated withdrawal. That judgment belongs to a prescriber assessing your symptoms, not to a number on a website.
Managing Side Effects Without Stopping Suboxone
Most side effects have a response short of quitting, and quitting is the option with the worst outcomes attached. The pros and cons of medication-assisted treatment set out that trade in full.
- Report anything new, including the awkward ones. Sexual side effects and low mood get left unsaid and then get treated as reasons to stop
- Do not stop Suboxone suddenly. Coming off without a plan risks withdrawal and relapse, and the weeks after leaving treatment carry the highest overdose risk of any period
- Keep the blood tests and the dental visits, since liver problems and dental damage are both far easier to prevent than to reverse
- Bring the full medication list, herbal or vitamin supplements included
- Give it four weeks before judging the side effects, unless something on the serious list appears
Medication is also only half of the treatment. Behavioral therapy alongside it is what most addiction treatment programs are built around, and it is the half that changes what happens once the medication has done its part. The medication makes behavioral therapy usable in the first place by taking withdrawal and cravings out of the way. Suboxone reduces cravings. It does not do the rest of the work. If alcohol is also in the picture, how does naltrexone work for alcohol covers the medications for that, and if your opioid exposure came through kratom, does Suboxone help with kratom withdrawal deals with it separately.
Suboxone Side Effects and Addiction Treatment in Iowa
If you are weighing whether the side effects are worth it, that comparison is not against feeling perfect. It is against untreated opioid use disorder, and on those terms it is not close. Opioid dependence left alone does not stay where it is.
Three questions worth asking a prescriber: which side effects you should call about immediately versus at the next appointment, whether they do baseline liver function testing, and what happens to your prescribed dose if a side effect does not settle.
Radix Recovery’s opioid addiction treatment program in Cedar Rapids uses buprenorphine and naloxone together, with naltrexone as the alternative, medication offered rather than required, and medical supervision alongside it. Programs that treat opioid addiction properly pair the prescription with therapy rather than handing it over on its own. If dependence itself is your objection, is Suboxone addictive handles that question directly, and Suboxone vs methadone compares the alternatives.
Your Life Iowa answers 24 hours a day on (855) 581-8111, takes texts on (855) 895-8398, and has live chat. It is run by the Division of Behavioral Health at the Iowa Department of Health and Human Services [5].
One last thing. Nearly every side effect on this page is either mild, manageable, or preventable with a glass of water and an hour’s patience. The one genuinely dangerous thing is combining Suboxone with benzodiazepines or alcohol. If you remember one item from this page, make it that one.
Sources
- Substance Abuse and Mental Health Services Administration. Chapter 3A: Overview of Medications for Opioid Use Disorder. Treatment Improvement Protocol (TIP) 63. https://www.ncbi.nlm.nih.gov/books/NBK574908/
- U.S. Food and Drug Administration. SUBOXONE (buprenorphine and naloxone) sublingual film prescribing information, 2022. https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/022410s046s047lbl.pdf
- U.S. Food and Drug Administration. FDA warns about dental problems with buprenorphine medicines dissolved in the mouth to treat opioid use disorder and pain. Drug Safety Communication, 2022. https://www.fda.gov/drugs/drug-safety-and-availability/fda-warns-about-dental-problems-buprenorphine-medicines-dissolved-mouth-treat-opioid-use-disorder
- 21 CFR 1306.07, Administering or dispensing of narcotic drugs. https://www.ecfr.gov/current/title-21/chapter-II/part-1306/subject-group-ECFR1eb5bb3a23fddd0/section-1306.07
- Your Life Iowa, Division of Behavioral Health, Iowa Department of Health and Human Services. https://yourlifeiowa.org/
