Sublocade is a once-monthly injection of buprenorphine that treats opioid use disorder by delivering a steady supply of medication from a small solid deposit under the skin. Unlike daily pills or films that dissolve under the tongue, a single injection maintains therapeutic drug levels for about 30 days, eliminating the need to take medication every day and reducing the risk of missed doses or diversion.
How the Injection Becomes a Slow-Release Depot
Sublocade enters the body as a liquid injected just under the skin of the abdomen. Once it contacts the moisture in your tissue, it solidifies into a small, firm mass called a depot. You can sometimes see or feel this as a small bump at the injection site. Over the following weeks, the depot slowly breaks down and releases buprenorphine into your bloodstream at a controlled rate. The bump gradually shrinks as the medication is absorbed, though it can remain noticeable for several weeks after each injection.
This delivery method is what makes Sublocade fundamentally different from sublingual buprenorphine (the films or tablets placed under the tongue). With daily formulations, blood levels of buprenorphine rise after each dose and fall before the next one. The depot provides a much more consistent level of medication around the clock, which means fewer cravings and a more stable treatment experience overall.
What Buprenorphine Does in the Brain
Buprenorphine is a partial opioid agonist. It activates the same brain receptors that heroin, fentanyl, and prescription painkillers target, but only partially. This partial activation is enough to reduce cravings and prevent withdrawal symptoms, but it produces a ceiling effect: beyond a certain dose, you don’t get increasing opioid effects. That ceiling is what makes buprenorphine far safer than full opioid agonists.
The Sublocade formulation was specifically designed to keep buprenorphine blood levels high enough to occupy at least 70% of the brain’s mu-opioid receptors. At concentrations of 2 ng/mL or higher, the medication effectively blocks the euphoric effects of other opioids. In clinical testing, the 300 mg dose provided effective blockade during hydromorphone challenge sessions, meaning patients who received the injection and then were exposed to another opioid reported minimal drug-liking effects. This blockade is a critical part of how Sublocade supports recovery: even if someone uses an opioid while on the medication, the expected “high” is dramatically blunted.
The Dosing Schedule
Treatment starts with two loading doses of 300 mg, given one month apart. These higher initial doses help build up buprenorphine levels in the body quickly. After those first two months, the standard maintenance dose drops to 100 mg monthly. If someone isn’t responding well at the lower dose, as indicated by continued opioid use or positive urine screens, the provider can increase the maintenance dose back to 300 mg monthly.
Before receiving the first injection, you need some exposure to sublingual buprenorphine to confirm you tolerate the medication. The traditional approach required at least seven days on daily sublingual buprenorphine at a stable dose of 8 to 24 mg. More recent labeling also supports a faster path: some patients can receive their first Sublocade injection after just a single 4 mg dose of sublingual buprenorphine. This faster induction option is particularly useful in clinical settings where someone needs to start treatment quickly and may not have reliable access to daily medication in the interim.
How Effective It Is
The pivotal clinical trial followed patients from week 5 through week 24. Both dosing groups (those who received 300 mg/100 mg and those who stayed at 300 mg/300 mg) showed significantly higher rates of opioid-free urine samples and self-reported abstinence compared to placebo, with both groups reaching statistical significance at p < 0.0001.
The trial defined “treatment success” as having 80% or more opioid-negative urine samples across the study period. About 28 to 29% of patients in the active treatment groups met this threshold, compared to just 2% in the placebo group. While 28% might sound modest on its own, opioid use disorder treatment trials use strict criteria. A patient could have a single positive sample out of many and fail to meet that 80% bar. The overall pattern showed a substantial and consistent reduction in opioid use across both dose groups.
Where You Can Get It
Sublocade isn’t available at a regular pharmacy. It’s distributed through a restricted program called the SUBLOCADE REMS, which exists because of safety concerns about potential intravenous misuse of the liquid formulation. Under this program, certified healthcare settings and pharmacies order the medication and provide it directly to a healthcare provider. The injection is always given by a provider in a clinical setting. You will never take Sublocade home or self-administer it.
This means each monthly visit involves going to a certified clinic, receiving the injection (typically in the abdominal area, with the site rotated each month), and being briefly monitored. For many people, trading 30 daily doses for one clinic visit is a significant reduction in treatment burden.
What the Injection Feels Like
The injection goes into the fatty tissue of the abdomen. Most people feel some pressure or mild discomfort during the injection itself. Afterward, the area where the depot forms may be tender, itchy, or slightly red for a few days. The solid lump that forms under the skin is normal and expected. It typically remains palpable for several weeks before gradually dissolving. You shouldn’t rub or massage the injection site, and providers rotate between different spots on the abdomen with each dose to avoid irritation.
What Happens If You Stop Treatment
Because the depot releases buprenorphine slowly, the medication doesn’t leave your system immediately after your last injection. Blood levels taper gradually over weeks to months, which provides a built-in cushion that daily formulations don’t offer. If you miss an appointment or decide to stop treatment, you won’t experience the abrupt withdrawal that can occur when stopping daily sublingual buprenorphine. This extended tail of medication can be a significant advantage for people transitioning off treatment, though it also means buprenorphine remains detectable in your system for a prolonged period after your final dose.