Naltrexone FAQ: 25+ Questions Answered
If you’ve been Googling naltrexone questions at 2 am, you’re in the right place. This hub covers every question people ask — from how the medication actually works to side effects, dosing, the Sinclair Method, telehealth prescriptions, and more. We’ve pulled together 25+ specific Q&As so you get a real answer, not a wall of vague medical disclaimers. Sunnyside has helped 600,000+ people drink less, and our telehealth platform, Sunnyside Med, connects people with naltrexone prescriptions starting at $99/month. Everything below is written to be genuinely useful, whether you’re just curious or already talking to your doctor.
How Naltrexone Works
What is naltrexone?
Naltrexone is a prescription medication used for alcohol use disorder (AUD) and opioid use disorder. It’s not new. It’s been around since the 1990s for alcohol treatment, which means we’ve got a few decades of data on it.
At a basic level, it interacts with the brain’s opioid receptors. Those are part of the system that helps create a sense of reward or relief. Alcohol happens to use that same pathway.
Naltrexone doesn’t make you sick if you drink. It doesn’t knock you out or dull your senses in that way. And it isn’t addictive. Most people take it as a daily pill (50 mg is standard). There’s also a monthly injection called Vivitrol, which does the same job more gradually over time.
How does naltrexone work for alcohol?
Alcohol doesn’t just “relax you.” There’s chemistry behind that feeling.
When you drink, your brain releases endorphins. Those endorphins attach to opioid receptors, and that’s part of what makes a drink feel rewarding—or makes a second drink feel like a good idea.
Naltrexone blocks those receptors. So the sequence still starts—you drink, brain reacts—but it doesn’t land the same way. The reinforcement piece is weaker. People describe it differently, but a common version is that the urge doesn’t build the same way.
Does naltrexone stop you from getting drunk?
No, it doesn’t change intoxication itself. If you drink the same amount you normally would, your blood alcohol level will rise the same way. Coordination, reaction time—all of that is unaffected by the medication.
What shifts is more behavioral than physical. It’s the moment after a drink, when you’re deciding whether to keep going. That’s where people tend to notice a difference.
Does naltrexone reduce cravings or block the buzz?
This is where it gets a little messy, because it’s not one or the other. Some people notice fewer cravings overall—like the background noise is lower, even on days they’re not drinking. Others mostly notice that once they start drinking, it’s easier to stop.
But it’s not identical across the board. Some people feel a big shift, and some people feel something more subtle. In general, outcomes improve when medication isn’t the only thing changing—when there’s some structure or support alongside it.
How long does it take for naltrexone to work?
It’s not immediate, which can be frustrating. Some people pick up on changes in the first couple of weeks—maybe they don’t finish a second drink, or the urge fades faster than expected.
But the more noticeable shift tends to build over time. Think in terms of weeks, not days. Sometimes longer. If nothing feels different right away, that doesn’t mean naltrexone is having no impact. It might just take a bit longer.
Does naltrexone work for everyone?
Studies show naltrexone can reduce heavy drinking and relapse risk for a meaningful portion of people, though it doesn’t work for everyone.
Researchers have also looked at why responses vary. One factor may be genetics—specifically a variation in the OPRM1 gene that affects opioid receptors. Some studies link this variant to a stronger response to naltrexone, though findings are mixed.
There’s also some evidence that naltrexone tends to work best for people who experience stronger cravings or reward-driven drinking patterns.
Taking Naltrexone
What is the standard naltrexone dose for alcohol?
Most people land at 50 mg per day. Sometimes folks might start lower—25 mg, for example—just to make the adjustment easier, especially if side effects show up early on.
There’s also the monthly shot (Vivitrol), which delivers a steady level of medication without needing to remember a pill.
Going above the standard dose isn’t typically helpful and can increase side effects, so changes should go through a prescriber.
Can I still drink while taking naltrexone?
Yes.
There’s no immediate negative reaction if you drink. No sudden nausea or flushing as you’d see with certain other medications.
The difference is more subtle than that. Drinking often feels less reinforcing, which can change how much you want to continue. For people trying to cut back, that tends to be the point.
When should I take naltrexone—morning or night?
There isn’t a single right answer here. Consistency matters more than timing. Same time every day is the general goal.
If nausea is an issue, taking it with food—or later in the day—can help. Some people prefer mornings so it’s already in their system. Others just pick whatever time they’re least likely to forget.
What happens if I miss a dose?
If you miss a dose, you don’t need to do anything special—just take the next one as scheduled.
Doubling up isn’t recommended.
One missed day usually doesn’t have a big impact, but if it becomes a pattern, the medication won’t work as consistently.
How long do I need to take naltrexone?
You’ll often see three to six months as a minimum timeframe. After that, it really depends on the person. Some continue for a year or more. Some stop sooner.
There’s no fixed endpoint built in. It’s more about whether it’s still helping and whether the underlying patterns have shifted enough to hold without it.
Can I stop taking naltrexone cold turkey?
Yes, you can stop without tapering. Naltrexone is not addictive, and there’s no withdrawal syndrome attached to it.
The tradeoff is that the effects go away pretty quickly once you stop—less support around cravings, less dampening of the reward response.
For some people, that’s fine at that point. For others, stopping too early can lead to a slow drift back to old habits. It’s usually worth talking it through with a prescriber before making that call.
Side Effects and Safety
What are naltrexone’s side effects?
In terms of side effects, nausea shows up the most in studies. Not in everyone, but a significant minority—enough that it’s “the one” people talk about. Headaches might happen, too, and fatigue. Perhaps a bit of stomach discomfort that usually doesn’t last long.
Most of it clusters early—first several days, maybe the first couple weeks. Then it tends to fade.
There are other reported effects—sleep feels off for some, occasionally dizziness, sometimes just a vague “not quite myself yet” feeling in the beginning.
Serious complications are rare at the standard 50 mg dose. Liver issues get mentioned a lot online, but clinically meaningful toxicity is uncommon at therapeutic levels and tends to show up in much higher-dose research contexts.
Does naltrexone make you tired?
Sometimes, yes.
But it’s inconsistent enough that it’s hard to pin down as a “classic” side effect. One person feels it, another doesn’t notice anything at all.
When it does show up, it’s usually early. Not permanent. More like a draggy feeling that sits in the background for a couple of weeks and then disappears.
People often adjust timing before anything else—morning dose becomes evening dose, or vice versa. It’s not always a perfect fix, but it’s often enough.
If it doesn’t ease up after a few weeks, that’s when clinicians usually start looking at dose or alternatives.
Does naltrexone cause weight loss or weight gain?
Not directly.
It doesn’t act on weight in a meaningful physiological way for most people. No metabolic push in either direction.
But alcohol does carry a lot of calories, and when drinking drops, intake often drops with it. So weight changes can happen, just indirectly. That’s usually what people are seeing.
There’s also confusion because naltrexone appears in Contrave (combined with bupropion), which is used for weight management. That version behaves differently because it’s part of a different system.
So: naltrexone alone isn’t a weight-loss drug. Any change is usually downstream of drinking less.
Is naltrexone addictive?
No.
It doesn’t activate reward pathways, doesn’t create dependence, and isn’t classified as a controlled substance.
Mechanistically it sits on opioid receptors and blocks them. That’s it. No “reinforcement loop,” no withdrawal pattern when stopping.
It’s one of the reasons it’s considered relatively low-risk in addiction medicine.
Can I take naltrexone with antidepressants?
Usually yes, and this comes up a lot in practice.
SSRIs, SNRIs—most of the common antidepressants don’t meaningfully interact with naltrexone. So combinations like sertraline + naltrexone are fairly routine in real-world treatment.
Where things get more complicated isn’t the antidepressants themselves, but whether opioids are involved anywhere else in the picture.
That’s the piece clinicians really screen for.
Otherwise, it’s generally a straightforward combination. Naltrexone doesn’t have major known interactions with most common antidepressants, though clinicians still review combinations—especially if other medications affect the liver.
Is naltrexone safe for the liver?
At standard doses, naltrexone is generally considered safe for most people. However, it isn’t recommended in cases of acute hepatitis or liver failure and typically involves some baseline monitoring from your doctor.
Can I take naltrexone if I also use opioids?
No — this one is important.
If opioids are in your system and you take naltrexone, it can trigger sudden withdrawal. Not mild discomfort. Real precipitated withdrawal that can escalate quickly. So there needs to be a clean opioid-free window before starting—often at least 7–10 days, sometimes longer depending on the substance.
Clinicians take this seriously because it’s not a subtle interaction. If you are currently using opioids, that has to be disclosed before starting naltrexone.
Naltrexone vs. Other Medications
What’s the difference between naltrexone and Antabuse (disulfiram)?
They don’t really behave like similar medications at all.
Naltrexone changes reward. Drinking still happens, but it tends to feel less compelling over time.
Antabuse (disulfiram) is more direct—it creates a physical reaction if alcohol is consumed. Flushing, nausea, palpitations. Very unpleasant. Sometimes severe. So the goal is different: One reduces reinforcement, the other creates deterrence.
One another important difference: Antabuse requires strong adherence. Naltrexone is more forgiving if timing varies.
What’s the difference between naltrexone and acamprosate?
It depends on what stage someone is in, which is why they’re often discussed side by side.
Naltrexone is more about reducing reward while drinking is still happening.
Acamprosate, by contrast, works more on stabilizing brain chemistry after someone has already stopped drinking. It’s often used to support abstinence and reduce the sense of restlessness or internal discomfort in early sobriety.
In large studies, naltrexone tends to show stronger effects on reducing heavy drinking. Acamprosate shows stronger effects in maintaining abstinence once someone has already stopped.
They’re not interchangeable. Instead, think of them as tools used in different situations.
Is Vivitrol the same as naltrexone?
Yes, but the delivery changes how it behaves in practice.
The medication is the same, but the form is different: an injectable instead of a daily pill. Vivitrol is given once a month, which solves the “remembering a pill” issue. But it also removes flexibility—once you’ve taken it for the month, you’ve taken it for the month.
If side effects show up, you can’t just stop it the way you can with oral naltrexone. That tradeoff is the main decision point.
Is naltrexone the same as Suboxone?
No. They’re often confused because their effects are both related to opioid receptors, but they are different medications.
Suboxone (buprenorphine + naloxone) partially activates opioid receptors and is used for opioid use disorder.
Naltrexone is an opioid antagonist, which means it blocks those receptors entirely.
Opposite mechanisms, different clinical roles.
Getting a Prescription
Can my regular doctor prescribe naltrexone?
Yes. Any licensed prescriber can, so going through your primary care provider is totally possible. Some are very comfortable with it. Other providers aren’t likely to bring it up.
Telehealth—including resources like Sunnyside Med—has filled a lot of that gap for people who don’t get traction in a traditional visit.
Do I need a diagnosis to get it?
Not necessarily. A formal alcohol use disorder (AUD) diagnosis isn’t required in most cases. The more important question: Does it fit the individual’s patterns and goals?
It doesn’t require severe drinking or crisis-level use. Sometimes it starts much earlier than that—when someone just feels their drinking isn’t where they want it to be.
Can I get naltrexone through telehealth?
Yes! And the process is usually simple: intake, screening, prescription if appropriate.
Sunnyside Med, through its licensed providers, provides access to compounded medication (naltrexone 50mg + B6 5mg). You’ll also get structured support from the Sunnyside app.
How much does naltrexone cost?
The medication itself is usually inexpensive—often in the $20–$50/month range for generic tablets, sometimes less with discount programs.
What varies more is the care layer around it (telehealth, coaching, subscriptions). For $99/month (no insurance required), Sunnyside Med offers personalized, doctor-prescribed medication, app support, and at-home delivery.
(Injectable Vivitrol is a completely different cost tier and can be significantly more expensive.)
Does insurance cover naltrexone?
Often, yes—but not uniformly. Most insurance plans cover generic oral naltrexone at least partially. Prior authorization can still come up depending on the plan. Coverage for injectable versions is more variable. Telehealth services may or may not be included depending on your insurance structure.
Last updated: April 2026. This page is reviewed monthly for accuracy.
