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Is Naltrexone a Controlled Substance?

What the federal rule and the DEA's list say about naltrexone's legal status, why it still needs a prescription, and what "not controlled" does not mean.

By Naltrexone Reviews Editorial TeamMedically reviewed byPietra Stanicki, MD, MSc on Updated 6 sourcesHow we check

Medically reviewed by

Pietra Stanicki, MD, MSc

General medicine · Argentina and Brazil

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Short answer

No. In the United States, naltrexone is not a federally controlled substance. The federal rule that defines Schedule II opiates names naltrexone as one of the drugs it excludes, and naltrexone does not appear on the DEA's list of controlled substances.1,2 It is still a prescription-only medicine.3,4

Key takeaways

  • Not controlled (federal): 21 CFR §1308.12(b)(1) excludes naltrexone, and its main breakdown product 6β-naltrexol, from Schedule II opiates.1,3
  • Vivitrol too: the monthly Vivitrol shot's active ingredient is naltrexone, and its label lists no DEA schedule.4
  • Still needs a prescription: both naltrexone tablets and Vivitrol are labeled "Rx only."3,4
  • Not habit-forming, per the labels: the labels say naltrexone does not lead to physical or psychological dependence.3,4
  • Not risk-free: after stopping naltrexone, people who used opioids before can overdose on lower doses than they used to.3,4
  • State law not checked: this page covers federal status only.

What "controlled substance" means

In the US, the Drug Enforcement Administration (DEA) publishes an alphabetical list of controlled substances. Each listed drug has a code number and a "CSA SCH" entry, which the list defines as its "CSA Schedule" (its schedule under the Controlled Substances Act). The current list uses five schedules, I through V.2 The legal text is in the Code of Federal Regulations (CFR). Schedule II, for example, is defined in 21 CFR §1308.12.1

What federal law says about naltrexone

Naltrexone is chemically related to oxymorphone, an opioid. The naltrexone label calls it "a synthetic congener of oxymorphone with no opioid agonist properties."3 Oxymorphone itself is a Schedule II drug.2 But the Schedule II rule, which covers opium, opiates, and drugs made from them, names naltrexone in its short list of exceptions:

"(1) Opium and opiate, and any salt, compound, derivative, or preparation of opium or opiate excluding apomorphine, thebaine-derived butorphanol, dextrorphan, nalbuphine, naldemedine, nalmefene, naloxegol, naloxone, 6β-naltrexol, naltrexone, and samidorphan, and their respective salts, but including the following"1

  • Naltrexone is named as an exclusion. So are its salts. The tablets contain naltrexone hydrochloride, which the label calls a "hydrochloride salt."1,3
  • Its main metabolite is excluded too. The label says "The major metabolite of naltrexone is 6-β-naltrexol."3 That compound (written 6β-naltrexol in the rule) is also on the exclusion list.1
  • Naloxone (Narcan) is also excluded.1 See Naltrexone vs naloxone for how the two drugs differ.

Naltrexone is not on the DEA's list

The DEA's current Controlled Substances – Alphabetical Order list does not include naltrexone, because it is not a controlled substance.2 Because it is not listed, it also has no entry in the list's "NARC" (narcotic) column.2

Two listed drugs to keep separate from naltrexone:

Two DEA-listed drugs that are sometimes confused with naltrexone (DEA list dated August 27, 2026).

  • Listed drug: Nalorphine (other name: Nalline)

    DEA schedule
    Schedule III2
    Is it naltrexone?
    No. A different drug.

  • Listed drug: Buprenorphine (other names include Subutex and Suboxone)

    DEA schedule
    Schedule III2
    Is it naltrexone?
    No. Buprenorphine is a different medicine.

Is Vivitrol a controlled substance?

No. Vivitrol is a monthly injection whose active ingredient is naltrexone.4 The federal exclusion covers naltrexone and its salts.1 The Vivitrol label lists no DEA schedule and is marked "Rx Only."4 Learn more in our Vivitrol guide.

What naltrexone does in the body

The labels describe naltrexone as a pure blocker of opioid receptors:

  • It "markedly attenuates or completely blocks, reversibly, the subjective effects of opioids."3
  • It "has few, if any, intrinsic actions besides its opioid blocking properties."3,4
  • "It does not lead to physical or psychological dependence. Tolerance to the opioid antagonist effect is not known to occur."3
  • "The administration of VIVITROL is not associated with the development of tolerance or dependence."4

How the drug blocks opioids is explained under how naltrexone works.

Not controlled, but still prescription-only

"Not controlled" does not mean "available without a prescription."

  • Naltrexone tablets are labeled "Rx only."3
  • Vivitrol "must be prepared and administered by a healthcare provider."4
  • The over-the-counter opioid overdose-reversal medicine you may have seen in pharmacies is naloxone nasal spray, not naltrexone. In 2023 the FDA approved Narcan 4 mg as "the first naloxone product approved for use without a prescription," and RiVive 3 mg a few months later.5,6

Ways to get a prescription are covered in Where to get naltrexone online.

Not controlled doesn't mean risk-free

Both labels carry serious warnings, though not a boxed warning3,4:

  • Withdrawal if opioids are still in your body. Naltrexone can cause sudden opioid withdrawal in people who are physically dependent on opioids. For patients previously dependent on short-acting opioids, the naltrexone tablet label recommends at least 7–10 opioid-free days before starting treatment. Patients transitioning from methadone or buprenorphine may remain vulnerable to precipitated withdrawal for up to two weeks.3
  • Overdose risk after stopping. The label warns that "patients who have been treated with naltrexone hydrochloride may respond to lower doses of opioids than previously used."3 For Vivitrol, the risk is highlighted near the end of the month after a shot, or after a missed dose.4
  • Trying to "push through" the block is dangerous. The blockade "is surmountable," and taking large amounts of opioids to overcome it "may lead to life-threatening opioid intoxication or fatal overdose."3
  • Keep a reversal drug on hand. The labels tell prescribers to talk with patients and caregivers about opioid overdose reversal agents such as naloxone and nalmefene.3,4
  • Liver. "Cases of hepatitis and clinically significant liver dysfunction" have been seen with naltrexone.3 See Naltrexone and liver tests (ALT/AST).

If you take naltrexone, the label suggests carrying identification that says so, in case of an emergency.3

What about state law?

This page covers federal status only. We have not checked each state's controlled-substance schedule.

Frequently asked questions

Is naltrexone a controlled substance?

No, not under federal law. 21 CFR §1308.12(b)(1) excludes naltrexone and its salts from Schedule II opiates, and naltrexone is not on the DEA's alphabetical list of controlled substances (dated August 27, 2026). State rules were not checked for this page.1,2

What schedule is naltrexone?

None. Naltrexone has no federal schedule because it is not on the DEA's controlled-substances list.2

Is Vivitrol a controlled substance?

No. Vivitrol's active ingredient is naltrexone, which federal law excludes from Schedule II. The Vivitrol label lists no DEA schedule. It is a prescription drug that a healthcare provider must prepare and give.1,4

Is naltrexone a narcotic or an opioid?

Naltrexone is an opioid antagonist, which means it blocks opioid receptors. The label describes it as chemically related to oxymorphone but "with no opioid agonist properties." It is not on the DEA's controlled-substances list, so it has no "narcotic" flag there.2,3

What class of drug is naltrexone?

Naltrexone is an opioid antagonist. The Vivitrol label says it has the "highest affinity for the mu opioid receptor."3,4

Is naltrexone addictive?

The tablet label says naltrexone "does not lead to physical or psychological dependence," and the Vivitrol label says it "is not associated with the development of tolerance or dependence." That does not make it risk-free; see the warnings above.3,4

Can you get naltrexone over the counter?

No. Naltrexone tablets and Vivitrol are prescription-only. The opioid medicines sold without a prescription include naloxone nasal sprays (Narcan 4 mg and RiVive 3 mg), a different drug.3-6

Is naltrexone the same as Suboxone?

No. The DEA lists Suboxone as a name for buprenorphine, a Schedule III drug. Naltrexone is not on the list at all. See naltrexone vs Suboxone.2

Will naltrexone make me test positive for opiates?

The labels say it might, depending on the test. Vivitrol "may be cross-reactive with certain immunoassay methods for the detection of drugs of abuse (specifically opioids) in urine." Oral naltrexone "may or may not interfere with enzymatic methods for the detection of opioids depending on the specificity of the test." More in How long does naltrexone stay in your system?3,4

Related guides

References

6 sources, numbered in the order they are first cited (AMA style). Each is labelled by type so you can weigh it; commercial and media sources are never the only support for a clinical claim.

  1. 1.Schedule II, 21 CFR §1308.12 (2026). eCFR version as of October 1, 2026. Accessed October 17, 2026. https://www.ecfr.gov/current/title-21/chapter-II/part-1308/section-1308.12Government source
  2. 2.Controlled substances – alphabetical order. US Drug Enforcement Administration, Diversion Control Division. August 27, 2026. Accessed October 17, 2026. https://www.deadiversion.usdoj.gov/schedules/orangebook/c_cs_alpha.pdfGovernment source
  3. 3.Naltrexone hydrochloride tablets USP, 50 mg. Prescribing information. SpecGx LLC; revised May 2026. DailyMed SPL version 15. Accessed October 17, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=06ff2d5a-e62b-4fa4-bbdb-01938535bc65FDA drug label
  4. 4.Vivitrol (naltrexone for extended-release injectable suspension). Prescribing information. Alkermes, Inc.; revised May 2026. DailyMed SPL version 39. Accessed October 17, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cd11c435-b0f0-4bb9-ae78-60f101f3703fFDA drug label
  5. 5.FDA approves first over-the-counter naloxone nasal spray. News release. US Food and Drug Administration. March 29, 2023. Accessed October 17, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-over-counter-naloxone-nasal-sprayGovernment source
  6. 6.FDA approves second over-the-counter naloxone nasal spray product. News release. US Food and Drug Administration. July 28, 2023. Accessed October 17, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-second-over-counter-naloxone-nasal-spray-productGovernment source

Medical disclaimer

This page is for general information only and is not medical or legal advice. It does not replace advice from your own clinician, pharmacist, or a lawyer. Don't start, stop, or change a medicine without talking to your prescriber. If you think someone is having an opioid overdose, call 911.

Full medical disclaimer.