Sublocade & Brixadi: Long-Acting Buprenorphine Injections

Sublocade and Brixadi — long-acting buprenorphine injections for maintenance, the long discontinuation tail, and the single-shot exit strategy.

Sublocade and Brixadi are two FDA-approved long-acting buprenorphine injections used in medication-assisted treatment (MAT) for opioid use disorder. Both contain buprenorphine, the same active ingredient as Suboxone, just delivered as a slow-release subcutaneous depot rather than as a daily sublingual film or tablet.

This page exists for two reasons. First, some people in this community have been offered these injections by their prescribers, and the pharmacology, dosing, and discontinuation profile differ enough from oral Suboxone that you should understand them before agreeing to one. Second, and increasingly relevant for this site’s audience, a single shot of long-acting buprenorphine followed by discontinuation is showing promising results as an exit tool for people who have been on long-term sublingual Suboxone and can’t get past the bottom of a sublingual taper. That use case has its own section below.

Heads up about this site’s focus: these injections were designed for stable, sustained maintenance dosing over months to years. This site leans toward short-term tapers, so if you’re early in recovery and haven’t tried a sublingual rapid taper yet, that’s where to start. Where these injections become directly relevant for our readers is the single-shot-exit use case, see Using a single shot as an exit from long-term Suboxone below.

Sublocade and Brixadi: overview

Sublocade (approved 2017) is a monthly subcutaneous injection. The liquid forms a solid depot under the skin that releases buprenorphine over ~28 to 30 days. Doses: 100 mg or 300 mg.

Brixadi (approved May 2023) is a subcutaneous injection that comes in both weekly and monthly formulations, providing more dosing flexibility than Sublocade. Weekly doses: 8, 16, 24, or 32 mg. Monthly doses: 64, 96, or 128 mg.

Key differences

Dosing flexibility: Brixadi offers weekly or monthly options; Sublocade is monthly only.
Injection sites: Sublocade is injected in the abdomen only. Brixadi can be injected in the buttock, thigh, abdomen, or upper arm.
Initiation requirements: Sublocade requires at least one dose of transmucosal buprenorphine and a 1-hour observation period before injection. Brixadi can be initiated with a single test dose of transmucosal buprenorphine, and weekly Brixadi can be used to start treatment in people new to buprenorphine.
Dose strength: Sublocade only comes in higher doses; Brixadi has lower-dose weekly options that some people find easier to start with.

Mechanism

The depot under the skin releases buprenorphine into the bloodstream at a controlled rate. Once steady-state is reached (typically after a few injections), plasma buprenorphine levels stay relatively constant between doses, which avoids the daily peak-and-trough cycle of oral Suboxone. For people whose adherence is a problem with daily dosing, this is a significant practical advantage. For people who are stable on oral and want fine-grained dose control, it removes that flexibility.

The very long half-life (this is the part that matters most)

The terminal half-life of Sublocade is 43 to 60 days. Brixadi monthly is similar; Brixadi weekly is shorter. For comparison, oral buprenorphine has a half-life of ~24 to 42 hours.

Practical consequences:

After a single Sublocade injection, buprenorphine remains detectable in the body for approximately 172 to 300 days (5 to 10 months).
After multiple injections, total elimination can take a year or more.
Withdrawal symptoms after stopping may not appear for several weeks after the last injection, then ramp up gradually as plasma levels finally drop.
Withdrawal symptoms may peak around 1 to 2 months after the last injection, not days like oral bupe.

This is the single most important thing to understand before agreeing to one of these injections. You are committing to a medication that will be in your body for many months after your last dose, whether you want it there or not. Once it’s injected, it can’t be removed (Sublocade can only be surgically removed within 14 days of injection, and only under specific clinical circumstances).

For some people, this is a feature: it removes daily decision-making, prevents missed doses, and provides a built-in slow taper if they decide to stop. For others, it’s a bug: it locks them into the medication and into clinic visits, and makes any change of plan slow.

Discontinuation profile

Because of the long half-life, stopping these injections is essentially a built-in slow taper. Plasma buprenorphine declines gradually over months. Some clinicians and patients view this favorably; some view it as a multi-month withdrawal tail rather than a clean exit.

Reddit-based qualitative research on stopping Sublocade found patients reported a wide range of experiences. Some had relatively mild withdrawal due to the gradual decline; others reported a long, drawn-out process with extended PAWS-like symptoms because plasma levels never drop sharply enough to trigger a clean withdrawal-then-recovery curve.

Brixadi’s prescribing information notes that if discontinued, ongoing buprenorphine effects should be monitored for ~1 month for weekly and ~4 months for monthly formulations.

Using a single shot as an exit from long-term Suboxone

This is the section to read if you’ve already been on daily Suboxone for months or years, you’ve tried a sublingual taper, and the bottom of the taper has been the wall.

A single dose of long-acting injectable buprenorphine, Sublocade or Brixadi, followed by discontinuation is showing promising results as an exit tool. It’s an off-label use of medications that were approved for maintenance, but it’s becoming a recognized strategy among MAT-experienced prescribers specifically for helping patients leave MAT cleanly.

The mechanism

The depot under the skin releases buprenorphine slowly. Monthly Sublocade’s terminal half-life is 43 to 60 days; monthly Brixadi is similar. After a single injection and no further dosing, plasma buprenorphine declines over months rather than dropping the way it does when you stop daily dosing, the body sees an automatic, ultra-slow taper instead of the cliff that comes off a sublingual cut to zero.

For people whose specific blocker has been the acute withdrawal at the bottom of a sublingual taper (the 2 mg → 0 transition that chemistry rarely makes easier), this approach can convert that cliff into a multi-month glide.

Evidence so far

A small observational case series (Hayes & Mills et al. 2025, n=15) characterized withdrawal from long-acting injectable buprenorphine in patients discontinuing treatment. Some patients had mild or manageable courses; others had longer-tailed symptoms. The single- injection-then-stop pattern is documented in this and adjacent literature; cases are still small.
Larger Reddit-based qualitative research (PMC) found mixed results, some patients had relatively mild withdrawal due to the gradual decline; others reported protracted symptoms that ramped up weeks after the last injection.

The early signal is encouraging, the literature is still thin, and outcomes vary by individual. It’s not a guaranteed clean exit, and the multi-month tail is genuine. For the specific population this is aimed at, long-term sublingual Subs patients stuck at the bottom of a taper, it’s the most promising new exit option in this space in years.

Where this fits

You’ve been on daily Suboxone for months or years and lower-dose sublingual tapers (1 mg, 0.5 mg, 0.25 mg) have repeatedly failed at the bottom.
The blocker has specifically been the acute withdrawal at the end of the taper, not ongoing anhedonia, PAWS, or instability that longer maintenance would address.
You have a prescriber willing to consider an off-label single-dose injectable approach for taper purposes (a critical gating factor; the injectable is administered in-clinic, so you cannot DIY this).
You’re stable enough that a months-long tail of declining medication is something you can live through without it becoming a destabilizing uncertainty.

Where this doesn’t fit

You’re early in recovery and a short sublingual rapid taper hasn’t been tried yet. Start there.
You’re already at low daily doses (2 mg or below) and managing the drop is feasible with smaller sublingual cuts.
Your prescriber isn’t on board. This isn’t a path you can take on your own.
You can’t tolerate the idea of months of declining medication. Once injected, it can’t be removed (Sublocade can only be surgically removed within 14 days of injection, and only under specific clinical circumstances).

Trade-offs to understand

You’re committing to months of declining buprenorphine in your system. For some this is a feature (built-in taper, no daily decisions). For others it’s frustrating to have a medication you’ve decided to stop continuing to act on you.
The withdrawal tail varies. Outcomes range from mild and gradual to moderately rough at the 1-to-2-month mark. The literature is thin, be ready for either.
Cost. A single Sublocade or Brixadi injection runs roughly $2,100 to $2,200 list price (per drugs.com / GoodRx / Indivior savings page, 2024–2026). Insurance often covers it as MAT, but if your insurer has stopped considering you appropriate for MAT (because you’re stable), getting a single dose specifically for taper purposes can be a coverage fight worth budgeting time for.
Not all prescribers will do this. It’s an off-label use of an injectable marketed for maintenance. Some MAT-experienced prescribers see the logic; others won’t go off-label. Telehealth bupe providers generally won’t administer injectables, this requires an in-person clinic.

Questions for your prescriber

Have you used Sublocade or Brixadi as a single-dose taper tool before, and if so, what have outcomes looked like in your practice?
What dose would you recommend for taper purposes specifically (the case-series literature has used 100 mg Sublocade, not the standard 300 mg maintenance dose)?
What’s the realistic withdrawal timeline I should expect?
If symptoms get rough at the 6-to-12-week mark, what’s our backup plan, helper meds queued up, a return to low-dose sublingual, or something else?
Is the cost covered by my insurance for this indication, and what’s my out-of-pocket?

When injectables make sense

Adherence problems with daily oral dosing. Missing oral Suboxone doses can lead to relapse; injections eliminate that risk.
Stable maintenance over months to years is the actual goal (rather than a short taper).
High-stakes life situations (incarceration transitions, custody arrangements, employment requirements) where consistent treatment is critical.
Diversion or theft concerns in a household.
Cravings that aren’t controlled by oral bupe even at maximum dosing.

When injectables aren’t the fit

Short taper is the goal. These medications make a fast, controlled exit much harder. Once injected, the long tail is unavoidable.
You’re still figuring out the right dose. Dose changes are slow, monthly affairs rather than day-to-day adjustments.
You’re considering pregnancy. Talk to your prescriber. Buprenorphine is generally considered acceptable in pregnancy, but the long-acting nature complicates things if changes are needed.
You haven’t been stable on oral bupe for at least a week. Sublocade specifically requires this.
Cost or access issues. Brixadi requires REMS-certified providers and pharmacies.

Questions if your prescriber suggests one

What’s the long-term plan? Indefinite maintenance, or a defined endpoint?
If I want to stop, what does that look like, and how long will I feel effects after the last injection?
Why this over continuing oral bupe, in my specific situation?
For Brixadi: weekly or monthly, and why?
What happens if I miss an appointment or move away from this clinic?
Is the cost covered by my insurance, and what’s my out-of-pocket?
Can I switch back to oral bupe later if needed?

Cost and access notes

Both medications are expensive without insurance coverage. Sublocade list price runs roughly $2,100 to $2,200 per monthly injection. Brixadi pricing varies by dose. Most insurance plans cover one or both as part of MAT, but prior authorization is common. Manufacturer assistance programs exist for patients who qualify.

Both medications must be administered by a healthcare provider; you can’t take them home.

Sources

Reminder: This is informational content. Long-acting buprenorphine decisions should be made with a prescriber familiar with your specific situation, especially given the multi-month commitment these injections involve. The community here is mostly oriented toward shorter-term tapers, so if you’re considering long-term maintenance, additional resources like r/suboxone may be more useful.