Yes, Sublocade is an opioid, but not in the way most people think of opioids. It contains buprenorphine, a synthetic opioid that only partially activates the brain’s opioid receptors. This partial activation is what makes it useful for treating opioid use disorder: it reduces cravings and withdrawal symptoms without producing the intense high associated with full opioids like heroin, fentanyl, or oxycodone.
How Sublocade Differs From Other Opioids
Buprenorphine, the active ingredient in Sublocade, is classified as a partial opioid agonist. A full opioid agonist flips the brain’s opioid receptors all the way “on,” producing strong euphoria, pain relief, and respiratory depression. Buprenorphine only partially activates those same receptors, producing a much milder effect that plateaus at a certain dose no matter how much more you take.
This plateau is called a ceiling effect, and it’s the key safety distinction. In clinical studies, doubling the dose of buprenorphine increased pain relief significantly but did not increase respiratory depression, the breathing slowdown that causes most opioid overdose deaths. That built-in ceiling makes buprenorphine substantially harder to fatally overdose on compared to full opioids.
Buprenorphine also binds to opioid receptors with very high affinity, meaning it grips those receptors tightly and blocks other opioids from attaching. If someone uses heroin or fentanyl while on Sublocade, the effects are blunted because buprenorphine is already occupying the receptors.
Its Controlled Substance Classification
The DEA classifies buprenorphine products, including Sublocade, as Schedule III controlled substances. This places them in a category with a lower potential for abuse than Schedule I drugs (heroin) or Schedule II drugs (oxycodone, fentanyl). For context, Schedule III also includes products containing limited amounts of codeine.
Being a controlled substance means Sublocade is regulated, tracked, and can only be administered by healthcare providers. It cannot be dispensed from a retail pharmacy for home use.
What Sublocade Is Used For
The FDA approved Sublocade specifically for treating moderate to severe opioid use disorder. It is not prescribed for pain management. The goal is to stabilize people who are dependent on opioids by keeping steady levels of buprenorphine in the bloodstream, which suppresses cravings and prevents withdrawal.
Before starting Sublocade, you typically need to be stabilized on an oral or sublingual form of buprenorphine first. Once that transition is complete, Sublocade replaces the daily pill or film with a monthly injection.
How the Monthly Injection Works
Sublocade is given as a subcutaneous injection, meaning it goes just under the skin of the abdomen. The first two monthly injections are 300 mg each. After that, the maintenance dose drops to 100 mg per month, though some people stay on 300 mg if the lower dose doesn’t provide enough symptom control.
Once injected, the medication forms a small solid deposit under the skin that slowly releases buprenorphine over weeks. This delivery method eliminates the need to remember a daily dose and removes the possibility of diverting or misusing daily tablets. The drug has an exceptionally long half-life in this form: buprenorphine from a single injection can remain detectable in the blood for up to 12 months after the last dose, though at progressively lower levels. This long tail means there’s no abrupt “cliff” when someone stops treatment.
Common Side Effects
Because Sublocade is an opioid, it produces some opioid-related side effects, though they tend to be mild. In clinical trials, the most frequently reported issues were constipation (8 to 9% of participants), headache (8 to 9%), nausea (about 9%), and vomiting (5 to 9%). These are typical of buprenorphine regardless of how it’s delivered.
The injection itself can cause localized reactions. Itching at the injection site affected 6 to 10% of participants. A small lump often forms where the medication was deposited, which is normal and gradually shrinks as the drug is absorbed. The lump should not be rubbed, massaged, or pressed on, as this can affect how quickly the medication releases.
Why an Opioid Is Used to Treat Opioid Addiction
Using an opioid to treat opioid use disorder can seem counterintuitive, but the pharmacology makes it logical. Full opioid agonists create a cycle of intense highs followed by painful withdrawal, driving compulsive use. Buprenorphine occupies the same receptors just enough to prevent withdrawal and quiet cravings, but not enough to produce the reinforcing high that fuels addiction. It essentially stabilizes the brain’s opioid system rather than whipsawing it.
People on Sublocade are not “still using.” They’re on a medication that keeps their brain chemistry stable so they can function, work, and engage in recovery. The distinction matters: buprenorphine maintenance is associated with significantly better outcomes than abstinence-only approaches for opioid use disorder, including lower rates of relapse and overdose death.