Drug & supplement interaction

Kratom + Belzutifan

Belzutifan brand name: Welireg.

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

Kratom has a minor interaction with Belzutifan. Theoretically, kratom might increase the levels of drugs metabolized by CYP2C19.

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

Kratom and Belzutifan

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

Minor

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

Why this applies to Belzutifan

Belzutifan falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Kratom interacts with.

Theoretically, kratom might increase the levels of drugs metabolized by CYP2C19.
In vitro research shows that kratom extract weakly inhibits CYP2C19 enzyme activity.
Severity Minor 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 short version for belzutifan (Welireg): your body partly clears this cancer medicine using a liver enzyme called CYP2C19. In test-tube studies, kratom seems to mildly slow that same enzyme down. In theory, that could let a little more belzutifan build up in your system, which might nudge up its side effects like tiredness, dizziness, headache, or low red blood cell counts (anemia) that can leave you feeling worn out and short of breath.

I want to be honest though, this concern comes only from lab research, not from real patient studies, and it's rated as a minor, weak interaction. Belzutifan is not a prodrug, so it doesn't get switched off here. Still, kratom carries its own serious risks, and you're managing a tough condition. Please loop in your oncologist or pharmacist before mixing the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Kong WM, Chik Z, Ramachandra M, et al. Evaluation of the effects of Mitragyna speciosa alkaloid extract on cytochrome P450 enzymes using a high throughput assay. Molecules. 2011;16(9):7344-7356. 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 983 moderate, 11 minor known drug interactions in our database — the Belzutifan one above is one of them. If you take anything else, check it against the full list below.

Moderate 983 Minor 11 No known interaction 1,836 (incl. Belzutifan)
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 Belzutifan

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 Belzutifan, 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 Belzutifan

This page covers Kratom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Belzutifan page lists 60 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), Artichoke (moderate), Bacopa (moderate) and Baikal Skullcap (moderate).

By severity: 1 major · 45 moderate · 14 minor.

From our pharmacist’s overview on the Belzutifan page

“A drug like belzutifan (Welireg), taken long term to keep kidney and other tumors in check, only works if a steady amount reaches the blood, so I would be genuinely careful before adding supplements here. Most of the interactions on file shift how the liver clears the drug, through the CYP2C19 enzyme or the glucuronidation pathway, nud…”

Reviewed by 2 · Jul 18, 2026

Open the Belzutifan 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 Belzutifan 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 Belzutifan 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 25%

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

29 days ago today
Medication Belzutifan
Top half

#1,273 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 Belzutifan

What Is Belzutifan Used For?

Brand name: Welireg

Welireg treats several serious conditions. In adults with von Hippel-Lindau (VHL) disease, it targets associated kidney cancer (renal cell carcinoma), brain or spinal tumors (CNS hemangioblastomas), and pancreatic neuroendocrine tumors that don't need immediate surgery. It is also used in adults with clear cell renal cell carcinoma (ccRCC) — either after surgery to lower the risk of the cancer coming back (used with pembrolizumab or pembrolizumab and berahyaluronidase alfa-pmph), or as a single agent for advanced ccRCC that has already been treated with two other types of cancer drugs.

Welireg also treats pheochromocytoma or paraganglioma (PPGL) — rare tumors of the adrenal gland or nearby nerve tissue — in adults and in children 12 years and older when the tumor cannot be removed by surgery or has spread.

See full Belzutifan 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
983Moderate
11Minor
1,835No known interaction
983 Moderate 11 Minor 1,835 No interaction
Moderate

983 interactions

Showing 60 of 983 moderate interactions — see all 983 on the Kratom page.

Minor

11 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 Belzutifan, 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 Belzutifan supplement interactions › Every supplement checked against Belzutifan, ranked by severity Belzutifan 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 Belzutifan Together: Common Questions

Can you take Kratom with Belzutifan?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Kratom and Belzutifan interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Belzutifan 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.