Drug & supplement interaction

Kratom + Naltrexone Hydrochloride

Naltrexone Hydrochloride brand name: Revia.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Kratom has a moderate interaction with Naltrexone Hydrochloride. Taking kratom in combination with naltrexone might precipitate withdrawal.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Kratom and Naltrexone Hydrochloride

Here is the interaction we found between these two, with the evidence behind it.

Moderate

NALTREXONE (Vivitrol)

Taking kratom in combination with naltrexone might precipitate withdrawal.
Animal research shows that, while naltrexone does not antagonize the primary kratom alkaloid mitragynine, it does inhibit the behavioral effects of the metabolite 7-hyroxymitragynine by antagonizing its binding at the mu-opioid receptor. In humans, taking naltrexone has precipitated withdrawal from kratom. In one case, a patient chronically consuming kratom developed agitation, hallucinations, and delirium within about 2 hours of beginning oral naltrexone therapy. In another case, a 38-year-old male who was admitted to a residential rehabilitation treatment program for polysubstance abuse experienced opioid withdrawal after administration of intramuscular naltrexone. Although the patient reported discontinuing kratom, continued use was confirmed through positive urine mitragynine tests. Manufacturer guidance states that patients should be opioid-free for a minimum of 7-10 days prior to initiating treatment with naltrexone; this case report suggests that kratom use should be given similar consideration.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the key thing to understand: naltrexone works by blocking your opioid receptors. Kratom's alkaloids, especially a metabolite called 7-hydroxymitragynine, act on those very same receptors, almost like a natural opioid. So if you've been using kratom regularly and then take naltrexone, the naltrexone can suddenly kick those kratom compounds off your receptors and trigger a rough withdrawal reaction.

In real reports, people have developed agitation, hallucinations, confusion, sweating, nausea, and severe restlessness within a couple of hours of starting naltrexone. The evidence here is anecdotal (a few case reports), but the mechanism makes sense. Because of this, being kratom-free for a stretch of time before starting naltrexone matters. Please don't adjust anything on your own. Talk with your doctor or pharmacist first so they can time this safely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Jensen AN, Truong QN, Jameson M, Nadal CN. Kratom-induced transaminitis with subsequent precipitated opioid withdrawal following naltrexone. Ment Health Clin 2021;11(3):220-224. PubMed
  2. Obeng S, Leon F, Patel A, et al. Interactive Effects of µ-Opioid and Adrenergic-a (2) Receptor Agonists in Rats: Pharmacological Investigation of the Primary Kratom Alkaloid Mitragynine and Its Metabolite 7-Hydroxymitragynine. J Pharmacol Exp Ther 2022;38
  3. Jarka C, Gregoire K. Precipitated withdrawal with kratom use following naltrexone administration. Ment Health Clin 2023;13(3):155-158. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Kratom Also Interacts With Other Medications

Kratom has 982 moderate, 12 minor known drug interactions in our database — the Naltrexone Hydrochloride one above is one of them. If you take anything else, check it against the full list below.

Moderate 982 Minor 12 No known interaction 1,836 (incl. Naltrexone Hydrochloride)
Taking anything else?

Check Another of Your Medications Against Kratom

Covers the 2,830 medications we’ve checked against Kratom. Pick one to open its full report.

From our Q&A

Questions About Kratom or Naltrexone Hydrochloride

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Kratom or Naltrexone Hydrochloride, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Naltrexone Hydrochloride

This page covers Kratom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Naltrexone Hydrochloride page lists 56 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Ashwagandha (moderate).

Open the Naltrexone Hydrochloride interaction page

One more smart check

Taking Kratom as Part of a Dietary Supplement Product? Check It for Interactions

We hold 8 real supplement products containing Kratom, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Kratom. Your product may carry other ingredients that interact with Naltrexone Hydrochloride too, on top of Kratom — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Kratom and Naltrexone Hydrochloride Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Kratom
Top half

#366 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Naltrexone Hydrochloride
Steady interest

#2,570 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Kratom

What is Kratom?

Kratom
  • Pain relief
  • Opioid withdrawal symptoms
  • Anxiety and stress
  • Low energy or fatigue
  • Mood enhancement

Kratom is a Southeast Asian plant whose leaves act on the brain's opioid receptors and can produce both stimulant-like and opioid-like effects. It is not approved or proven safe by health regulators, carries real risks of dependence and serious harm, and its legal status varies widely. Talk to a pharmacist or doctor before considering it.

Read the full Kratom monograph & all interactions
Medication

About Naltrexone

What Is Naltrexone Used For?

Brand name: Revia

Naltrexone Hydrochloride tablets are used to treat alcohol dependence and to block the effects of opioids in people with opioid dependence. The extended-release injectable suspension — sold as Vivitrol and also available as a generic injectable — is used to treat alcohol dependence and to prevent relapse to opioid dependence after a person has completed opioid detoxification.

All formulations are meant to be part of a broader treatment plan that includes counseling and other support — naltrexone works best when it is not used alone.

See full Naltrexone drug information
Keep checking

Other Drugs & Kratom

Browse every other medication we’ve checked against Kratom — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
982Moderate
12Minor
1,835No known interaction
982 Moderate 12 Minor 1,835 No interaction
Moderate

982 interactions

Showing 60 of 982 moderate interactions — see all 982 on the Kratom page.

Minor

12 interactions

No interaction 1,835 drugs checked — show the list

We also checked Kratom against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,835 medications checked with no known interaction — see the full Kratom list.

See the full Kratom interactions page
See every supplement checked against Naltrexone Hydrochloride, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Kratom monograph › Uses, safety, and every drug interaction in one place Naltrexone Hydrochloride supplement interactions › Every supplement checked against Naltrexone Hydrochloride, ranked by severity Naltrexone drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Kratom and Naltrexone Hydrochloride Together: Common Questions

Can you take Kratom with Naltrexone Hydrochloride?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Kratom and Naltrexone Hydrochloride interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Naltrexone Hydrochloride and Kratom?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.