What Is Low-Dose Naltrexone, and Can It Reduce Alcohol Consumption?

Medically reviewed by John Mendelson, M.D. on

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Many people ask us whether very low doses of naltrexone can be used to treat alcohol use disorder (AUD). And it’s a good question. Early research has shown low-dose naltrexone (LDN) to be a promising treatment for multiple chronic disorders. Studies also suggest it could be effective for other substance dependencies. Still, the answer isn’t cut-and-dried.

In this post, we’ll discuss what LDN is, and whether it’s as effective as a full dose of naltrexone for AUD.

Read more about the standard use of Naltrexone for Alcohol Use Disorder

That’s a good question. The verdict is still out on that. Because for some people yes, some people no. It all goes back to—as I always say—medicine is called a “practice” for a reason: “Let’s try this and see if it works.” And it’s not a good feeling to be on the receiving end of that, feeling like a guinea pig. But at the same time, that’s the best we have.

For some people—and it depends on how a person metabolizes naltrexone (some people are fast metabolizers)—they need a high dose in order to get proper blood levels in their system. Other people are slower metabolizers.

For some people, we have had to send low-dose prescriptions to compounding pharmacies for low-dose naltrexone, because that’s all they can tolerate, or that’s all they need. We always say the lowest effective dose is what we want. If 10 milligrams does it, there’s no reason to go higher, especially if it’s just going to increase your risk for side effects.

If low-dose naltrexone works for you, great. We encourage taking the lowest effective dose. Oftentimes people do need higher doses, and that is backed up with medical studies.

The receptor we’re trying to target in addictions regarding naltrexone is the kappa receptor.

Naltrexone is used for opiate addiction in that it’s targeting the mu receptor, which is an antagonist that blocks it completely. That’s why naltrexone blocks all opiates. But for alcohol—alcohol’s not an opiate, nor are we trying to hit that receptor—we’re trying to hit the other one, the kappa receptor.

A research study says that at 50 milligrams, which is a standard dose of naltrexone, the kappa receptor is about 60% full. For a lot of people, that works for them. At 100 milligrams of naltrexone, that kappa receptor is between 90% and 95%. Some people need that little extra difference.

And there are cases where we have gone higher—150 milligrams—and at that point, does the benefit really outweigh the risk? Because you’re really only getting that extra 5% or 10% of capture on that kappa receptor, but you’re also increasing your risk for side effects. Once you get above 100 milligrams, I recommend getting a liver function test often and your doctor will monitor that.

Dosage is something to consider. Some people can get the good effect at 12 milligrams—a quarter tablet of naltrexone—and they’re fine. Other people need 100 milligrams. So it all depends on how your body metabolizes it.

What is Low-Dose Naltrexone (LDN)?

Can low-dose naltrexone treat alcohol use disorder?


Image by Michal Jarmoluk from Pixabay

Naltrexone is an opiate antagonist used to treat a variety of conditions, including problem drinking. Doctors typically prescribe 50 mg tablets of naltrexone for AUD patients. But there are also tablets that contain only a few milligrams of naltrexone. That’s “low-dose naltrexone,” and it’s used to treat a different set of conditions.

Although not specifically approved by the FDA for these purposes, LDN can be used off-label to treat chronic pain from fibromyalgia, arthritis, and other inflammatory diseases. It may also benefit people with immune disorders and even cancer.

Although further research is needed to pinpoint exactly why patients experience relief, it’s believed that LDN works by increasing endorphins.

LDN is typically prescribed in starting doses of 0.5 mg to 1.5 mg, increasing to 4.5 mg or higher over the course of several weeks. Compare that to the typical starting dose of 25 mg for alcohol use disorder, ultimately increasing to 50 mg. That’s the dose we typically prescribe Ria Health members. It’s also what the Sinclair Method recommends to treat problem drinking.

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What’s the Difference Between LDN and Naltrexone for AUD?

Can low-dose naltrexone work to treat alcohol dependence, even though it’s more than 10 times less than a typical dose?

Since most studies on naltrexone and AUD evaluate 50 mg doses, there isn’t enough research to conclusively determine whether LDN can also treat AUD. The research that has been done has focused on low doses of naltrexone combined with other drugs or other substance dependencies, like this 2017 study on LDN and the antidepressant bupropion.

2011 study investigated the effects of very low-dose naltrexone on opioid detox patients who were also problem drinkers—as heavy drinking can make opioid withdrawal worse. Researchers found that those who took very lose doses of naltrexone showed fewer withdrawal symptoms. They were also more likely to continue treatment, and drank less in the days after leaving treatment.

Another study by researchers at the University of Maryland showed that LDN combined with the dopamine antagonist 1-THP may improve relapse behavior more than naltrexone alone—at least in cocaine-addicted rodents.

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Can Low-Dose Naltrexone Treat Alcohol Use Disorder?

The jury’s still out. There simply hasn’t been enough research to determine whether low-dose naltrexone can help with AUD. And since 50 mg doses have already been proven extremely effective, most doctors will recommend a full dose of naltrexone instead. Side effects are relatively rare, mild, and tend to go away after your body has adjusted to the medication. If you’re worried about potential side effects, ask your doctor about starting at a 25 mg dose and slowly increasing it.

Ria Health combines medication and counseling for effective and compassionate treatment. You don’t even need to leave your home. Start mending your relationship with alcohol today.

What to Avoid When Taking Low-Dose Naltrexone

On its own, naltrexone is one of the safest medication options available for treatment of alcohol use disorder. And low-dose naltrexone (LDN) has an even lower rate of side effects. The FDA has approved LDN for patients 18 years or older.

That said, like most medications, LDN doesn’t always mix well with other things, especially opioids, which are commonly found in analgesics such as hydrocodone, oxycodone, and codeine. But any prescription opioids (or illegal ones, such as heroin) should not be used while taking LDN. Also to be avoided: medications for diarrhea, and antihistamines for colds, such as promethazine (brand name: Phenergan).

Further, people with liver or kidney problems should not use LDN, as the medication is processed by the liver. As always, even though LDN is generally quite safe, patients should get advice from their doctor.

Written By:
Ria Health Team
Ria Health’s editorial team is a group of experienced copywriters, researchers, and healthcare professionals dedicated to removing stigma and improving public knowledge around alcohol use disorder. Articles written by the “Ria Team” are collaborative works completed by several members of our writing team, fact-checked and edited to a high standard of empathy and accuracy.
Reviewed By:
Evan O'Donnell
Evan O’Donnell is an NYC-based content strategist with four years’ experience writing and editing in the recovery space. He has conducted research in sound, cognition, and community building, has a background in independent music marketing, and continues to work as a composer. Evan is a deep believer in fact-based, empathic communication—within business, arts, academia, or any space where words drive action or change lives.
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