Short answer: The naltrexone label dose is 50 mg once daily for most people treated for alcohol dependence. For opioid dependence it starts at 25 mg, then 50 mg a day if no withdrawal signs occur. People must be opioid-free first, at least 7 to 10 days after short-acting opioids. Supervised schedules such as 100 mg every other day or 150 mg every third day are also listed.
This is what the FDA label says. Follow your prescriber. Your prescriber may use a different dose or pace than the label's standard schedule.
What Naltrexone is approved for: Naltrexone tablets are approved to treat alcohol dependence and to block the effects of opioids taken from outside the body (Indications and Usage). The label says they have not been shown to provide any benefit except as part of an appropriate plan of management for the addictions.
Source
Naltrexone Hydrochloride Tablets, USP 50 mg, prescribing information. SpecGx LLC (Par Health). DailyMed, version published September 9, 2026. DailyMed setid 06ff2d5a-e62b-4fa4-bbdb-01938535bc65
Naltrexone is a 50 mg tablet taken by mouth, with a score line across the middle (How Supplied).
Before the first dose, people must be opioid-free, including tramadol. A naloxone challenge test may be used if there is any question of hidden opioid dependence (Dosage and Administration).
The label says naltrexone is of proven value only as part of a broader treatment plan, and that it works only when taken (Dosage and Administration, Patient Compliance).
The table below is the label's schedule, from the Dosage and Administration section. Numbers are copied exactly; the section is in brackets.
| Use | Starting dose | Usual dose | Notes from the label |
|---|---|---|---|
| Alcohol dependence | 50 mg once daily | 50 mg once daily for most patients | Efficacy trials used 50 mg once daily for up to 12 weeks; other regimens or durations were not evaluated |
| Opioid dependence | 25 mg | 50 mg a day if no withdrawal signs occur | 50 mg once a day produces adequate blockade of injected opioids |
| Supervised alternative schedules | Not applicable | 50 mg every weekday with 100 mg on Saturday, 100 mg every other day, or 150 mg every third day | The degree of blockade may be reduced by these longer intervals, and single doses above 50 mg may carry a higher risk of liver injury |
| Route | Step | What follows |
|---|---|---|
| Intravenous | Inject 0.2 mg naloxone and observe for 30 seconds | If no withdrawal, inject 0.6 mg naloxone and observe for 20 more minutes |
| Subcutaneous | Give 0.8 mg naloxone | Observe for 20 minutes |
| Positive test (withdrawal signs) | Do not start naltrexone | Repeat the challenge in 24 hours |
Opioid-dependent people, including those treated for alcohol dependence, should be opioid-free (including tramadol) before starting. An opioid-free interval of at least 7 to 10 days is recommended after short-acting opioids.
People switching from buprenorphine, buprenorphine/naloxone or methadone may be vulnerable to precipitated withdrawal for as long as 2 weeks; there are no systematically collected data on this switch.
When starting and renewing treatment, the label says to discuss access to an opioid overdose reversal agent such as naloxone, because of overdose risk after treatment stops or after a missed dose.
The challenge is not done in someone showing withdrawal signs or whose urine contains opioids. If the result is in doubt, naltrexone is held and the challenge repeated in 24 hours.
There may be a higher risk of liver cell injury with single doses above 50 mg, and higher doses and longer intervals should balance possible risks against probable benefits.
The naltrexone tablet label gives no missed-dose rule. It notes only that the risk of opioid overdose applies after treatment is stopped or after a dose is missed, and says to discuss access to an overdose reversal agent.
More on this: missed a dose of Naltrexone.
Switching from buprenorphine or methadone: some people had severe precipitated withdrawal when switched from opioid agonist therapy to naltrexone, and they may be vulnerable for as long as 2 weeks. Healthcare providers should be prepared to manage withdrawal with non-opioid medicines.
In Dose Track you set up Naltrexone as a protocol with the dose and schedule your prescriber gave you. A protocol can hold dose steps, each with its own dose and length in days or weeks, so a step-up plan like the one on the label can be entered once and the app moves to the next step on its own. Reminders follow the schedule, and every dose is logged with the date and time, so you can see which step you are on and when your last dose was. The app follows what you enter; it does not choose or change a dose.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.