Suboxone contains two active drugs: buprenorphine and naloxone, combined in a 4:1 ratio. In an 8 mg film, for example, you get 8 mg of buprenorphine and 2 mg of naloxone. These two ingredients serve very different purposes, and understanding what each one does explains why they’re packaged together.
The Two Active Ingredients
Buprenorphine is the primary therapeutic ingredient. It’s a partial opioid agonist, meaning it activates the same receptors in the brain that full opioids like heroin or oxycodone target, but only partially. Think of it like a key that fits the lock but only turns halfway. This partial activation is enough to reduce cravings and prevent withdrawal symptoms, but it doesn’t produce the intense high of a full opioid.
Buprenorphine also has a built-in safety feature called a ceiling effect. After a certain dose, taking more doesn’t increase its effects on breathing. This makes it significantly safer than methadone or full opioids, where higher doses can dangerously slow respiration. It also binds very tightly to opioid receptors and releases slowly, which is why a single daily dose can keep withdrawal at bay for 24 hours or longer.
Naloxone is the second active ingredient. It’s an opioid blocker, the same drug used in Narcan to reverse overdoses. Its role in Suboxone is specifically to discourage misuse. When you take the film under your tongue as directed, naloxone has almost no effect because it’s barely absorbed that way. Its oral bioavailability is only 1 to 2 percent, so it essentially passes through your system without doing much. But if someone were to dissolve the film and inject it, naloxone would become fully active, blocking opioid receptors and triggering immediate withdrawal symptoms. It’s a tamper-deterrent, not a treatment component.
Available Dosage Strengths
Suboxone sublingual film comes in four FDA-approved strengths, all maintaining that 4:1 ratio:
- 2 mg/0.5 mg (buprenorphine/naloxone)
- 4 mg/1 mg
- 8 mg/2 mg
- 12 mg/3 mg
Most people on maintenance treatment take between 8 and 16 mg of buprenorphine daily, though the range can be as low as 4 mg or as high as 24 mg depending on the individual. The FDA does not recommend exceeding 24 mg, as there’s little evidence of additional benefit beyond that.
Inactive Ingredients in the Film
Beyond the two active drugs, each Suboxone film contains several inactive ingredients that give it its structure, flavor, and color. The film itself is formed primarily from polyethylene oxide and hydroxypropyl methylcellulose, which are the polymers that create its thin, dissolvable texture. Maltitol and acesulfame potassium act as sweeteners, while lime flavor and citric acid give it a citrus taste. Sodium citrate serves as a buffer to help control acidity. FD&C yellow #6 is responsible for the film’s orange color, and white ink is used for the printed logo on the surface.
These inactive ingredients matter more than you might think. The sweeteners and acidic components are part of why the FDA issued a safety warning in January 2022 about dental problems associated with buprenorphine films and tablets dissolved in the mouth.
The Dental Health Warning
In 2022, the FDA warned that dissolving buprenorphine products in the mouth has been linked to tooth decay, cavities, oral infections, and tooth loss, even in people with no prior dental problems. A review of adverse event reports identified 305 cases of dental issues, with 131 classified as serious. Some problems appeared as early as two weeks after starting treatment, though the typical time to diagnosis was about two years. The most commonly reported treatment was tooth extraction.
The recommended precaution is simple: after each film dissolves completely, take a large sip of water, swish it gently around your teeth and gums, and swallow. Wait at least one hour before brushing to avoid damaging enamel while your mouth is still in an acidic state. Regular dental checkups are especially important for anyone using these products long term.
How the Film Works in Your Body
Suboxone is placed under the tongue or against the inside of the cheek, where buprenorphine absorbs through the thin tissue directly into the bloodstream. This route bypasses the digestive system, which is important because buprenorphine is poorly absorbed if swallowed. Naloxone is also poorly absorbed through the mouth lining, which is exactly the point. It sits there inert when the film is used correctly.
Once absorbed, buprenorphine binds tightly to opioid receptors and dissociates slowly. This strong grip means it can actually block other opioids from attaching to those same receptors. If someone takes heroin or another opioid while on a stable dose of Suboxone, the effects will be significantly blunted because buprenorphine is already occupying the receptors and won’t let go easily.
Starting and Maintaining Treatment
Suboxone treatment typically begins during a period called induction, when a person transitions from their current opioid use to buprenorphine. Timing matters here. The person needs to be in at least mild withdrawal before taking the first dose. Starting too early, while other opioids are still active on receptors, can cause buprenorphine to displace them abruptly, triggering what’s called precipitated withdrawal, an intensely uncomfortable experience.
Once stabilized, most people settle into a daily maintenance dose. The goal is to find the amount that eliminates cravings and withdrawal without causing significant side effects. Common side effects include headache, nausea, constipation, insomnia, and sweating. Because of the ceiling effect, these tend to plateau rather than worsen at higher doses. Treatment duration varies widely. Some people take Suboxone for months, others for years, depending on their recovery and circumstances.