Medication interaction hub

What Supplements Interact with Methylnaltrexone?

Methylnaltrexone brand name: Relistor. Every interaction below applies to the brands too.

3 Interactions 3 Moderate
Curated & coded by · Clinical Pharmacist · Updated September 22, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Methylnaltrexone? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Methylnaltrexone against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

If you take methylnaltrexone (Relistor) for opioid-induced constipation, the supplement list to know is short: three ingredients, all rated moderate, none major. Yohimbe, fever bark, and iboga are all cleared by the same liver enzyme, CYP2D6, and methylnaltrexone can slow that enzyme, letting their active compounds build up in your blood. For most people this is a manageable list, as long as you know what those combinations do.

Notice the direction of the risk. None of these three will keep Relistor from relieving your constipation. Instead, the supplement hits harder, since higher blood levels mean stronger effects and stronger side effects. Yohimbe has the best evidence and is the one you will actually find on store shelves, sold for energy and sexual performance, so a yohimbe dose that felt fine before Relistor deserves a fresh look now.

— , Clinical Pharmacist · July 18, 2026

Moderate 3 No known interaction 1,449

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Top Ingredient Interactions

Methylnaltrexone: Top Interactions at a Glance

The most significant Methylnaltrexone supplement & herbal interactions, colored by severity. Tap any ingredient to open the full report for that pair.

Interacts with 3 ingredients Methylnaltrexone
Yohimbe Moderate Fever Bark Moderate Iboga Moderate

Showing the 3 highest-ranked of 3 interacting ingredients — plus 1,449 more checked with no known interaction. See the complete ranked list.

Start here

The Moderate Interactions to Know About

The most clinically significant Methylnaltrexone + supplement combinations in our database, best-documented first. Open any card for the full report.

Moderate Likelihood Probable Yohimbe + Methylnaltrexonei

CYP2D6 inhibitors may increase the levels and adverse effects of yohimbine, a constituent of yohimbe.

Read the full interaction Moderate Likelihood Possible Fever Bark + Methylnaltrexonei

Theoretically, CYP2D6 inhibitors might increase the levels and clinical effects of yohimbine, a constituent of fever bark.

Read the full interaction Moderate Likelihood Possible Iboga + Methylnaltrexonei

Theoretically, taking iboga with CYP2D6 inhibitors might increase the levels and clinical effects of ibogaine.

Read the full interaction
The complete list

Every Supplement Checked Against Methylnaltrexone

All 1,452 ingredients in our database, ranked by severity — 3 with a Methylnaltrexone interaction on file and 1,449 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Methylnaltrexone?

One-line answers, one card per combination — scroll through today’s 6 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Yohimbe with Methylnaltrexone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. CYP2D6 inhibitors may increase the levels and adverse effects of yohimbine, a constituent of yohimbe.

Full Yohimbe + Methylnaltrexone answer

Can you take Fever Bark with Methylnaltrexone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, CYP2D6 inhibitors might increase the levels and clinical effects of yohimbine, a constituent of fever bark.

Full Fever Bark + Methylnaltrexone answer

Can you take Iboga with Methylnaltrexone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking iboga with CYP2D6 inhibitors might increase the levels and clinical effects of ibogaine.

Full Iboga + Methylnaltrexone answer

Can you take Yohimbe with Methylnaltrexone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. CYP2D6 inhibitors may increase the levels and adverse effects of yohimbine, a constituent of yohimbe.

Full Yohimbe + Methylnaltrexone answer

Can you take Fever Bark with Methylnaltrexone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, CYP2D6 inhibitors might increase the levels and clinical effects of yohimbine, a constituent of fever bark.

Full Fever Bark + Methylnaltrexone answer

Can you take Iboga with Methylnaltrexone?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking iboga with CYP2D6 inhibitors might increase the levels and clinical effects of ibogaine.

Full Iboga + Methylnaltrexone answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction 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.
  • Possible. 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
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Methylnaltrexone is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Methylnaltrexone, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Methylnaltrexone sits in 1 interaction category. Open any one to see what the group means:

Cytochrome P450 2D6 (Cyp2D6) Inhibitors 3 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

3 of the supplement ingredients on this page reach Methylnaltrexone through this category.

About Methylnaltrexone

Methylnaltrexone (Relistor) is a targeted opioid antagonist used to treat opioid-induced constipation in adults with chronic non-cancer pain or advanced illness.

Generic name: Methylnaltrexone  ·  Brand name: Relistor.

See the full Methylnaltrexone drug information
Check a real product

Take a Supplement Product? Check the Whole Bottle Against Methylnaltrexone

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Methylnaltrexone.

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Grounded search over our product catalog — every verdict comes from our interaction database, never AI guesswork. How we use AI

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Photograph any Supplement Facts panel — we read the ingredients and check each one against your medications. Free, in seconds.

Open the label scanner

Prefer typing? The interaction checker looks up products by name too.

Products that contain Methylnaltrexone-interacting ingredients

Real supplements from the NIH label database that contain the top interacting ingredients on this page — each one is worth a full label check before combining with Methylnaltrexone.

Yohimbe by FINAFLEX contains Yohimbe Xcelerate Watermelon Berry by Beneve contains Yohimbe Ultra Pump Fuel v.5 Insanity Tropical Orange Mango by PMD contains Yohimbe Yohimbe 500 mg by Eurovital Nutraceuticals contains Yohimbe
Pharmacist Counseling Corner

Methylnaltrexone & Supplements: Common Questions

What supplements interact with Methylnaltrexone?
Our database currently documents 3 ingredients with a known Methylnaltrexone interaction (0 major, 3 moderate, 0 minor). The practical move: scan the major group first, then look up the exact supplements you take rather than reading all 3. The highest-ranked right now: Yohimbe, Fever Bark, Iboga.
Which Methylnaltrexone supplement interactions are the most serious?
None of the Methylnaltrexone supplement interactions on file are currently rated major. The most significant are the 3 moderate-rated ones — combinations that may need monitoring, a dose adjustment, or separated timing. Still worth a quick look through the ranked list for anything you take daily. Jump to the ranked list.
Can I take vitamins or supplements while on Methylnaltrexone?
Plenty of supplements coexist fine with Methylnaltrexone; a shorter list does not. Rather than memorizing it, check the specific ingredients on your labels — the ranked list above covers every one we've checked, and multi-ingredient products can be checked label-by-label with our scanner. Try the label scanner or the interaction checker.
Do brands like Relistor have the same supplement interactions as Methylnaltrexone?
Yes — Relistor all contain Methylnaltrexone, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
What about Methylnaltrexone and my other medications?
This page covers Methylnaltrexone against supplements and herbal ingredients. Checking Methylnaltrexone against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker, or read the full Methylnaltrexone drug information.

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

Where next

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of September 22, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.