Drug & supplement interaction

Cramp Bark + Larotrectinib

Larotrectinib brand name: Vitrakvi.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Cramp Bark and Larotrectinib in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Cramp Bark and Larotrectinib

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Larotrectinib and Cramp Bark in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Cramp Bark at all — not against Larotrectinib, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Cramp Bark safety at a glance

Cramp Bark overall Use caution Generally used in traditional medicine, but human safety data are limited.
Pregnancy Avoid Safety is not established, so it is best avoided during pregnancy.
Breastfeeding Avoid There is not enough safety information for breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Larotrectinib and Cramp Bark? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Larotrectinib’s Own FDA Label Lists

This is not an interaction — none of it involves Cramp Bark. These are the most notable effects listed in the ADVERSE REACTIONS section of Larotrectinib’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • Memory problems Worth acting on
  • Hallucinations Worth acting on
  • Confusion Worth acting on
  • A severe skin reaction Worth acting on
  • Chest pain Worth acting on
  • Low mood Worth acting on
  • Anemia Worth acting on
  • Shortness of breath Worth acting on
  • A low white blood cell count Worth acting on
  • Liver problems Worth acting on

Showing the 10 most notable of 38 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Larotrectinib. Read the label on DailyMed › Cramp Bark’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Cramp Bark side to compare — that is a limit of the record, not a statement that Cramp Bark has no side effects.

Everything else you take

See Every Supplement That Interacts With Larotrectinib

This page covers Cramp Bark only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Larotrectinib page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 100 moderate · 40 minor.

From our pharmacist’s overview on the Larotrectinib page

“Nearly everything on this page interacts with larotrectinib (Vitrakvi) in one of two directions, raising or lowering how much of the drug ends up in your blood. Larotrectinib treats cancers driven by an NTRK gene fusion, and it is cleared by a liver enzyme called CYP3A4, so herbs that speed that enzyme up can drain the drug's effect wh…”

Reviewed by 2 · Jul 18, 2026

Open the Larotrectinib interaction page

One more smart check

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

We hold 256 real supplement products containing Cramp Bark, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cramp Bark. Even though Cramp Bark itself has no known interaction with Larotrectinib, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cramp Bark and Larotrectinib 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 Cramp Bark
Top half

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

29 days ago today
Medication Larotrectinib
Steady interest

#2,487 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources.
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Cramp Bark and Larotrectinib records this page draws on were last updated June 22, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Cramp Bark

What is Cramp Bark?

  • Menstrual cramps
  • Muscle spasms
  • General cramping pain
  • Stomach or digestive cramps
  • Easing tension

Cramp Bark is the dried bark of Viburnum opulus, traditionally used to ease muscle and menstrual cramps. Modern, high-quality human studies are very limited, so its effectiveness is not well proven. If you want to try it, talk with your pharmacist or doctor first, and avoid it during pregnancy because safety is unclear.

Viburnum opulus · Adoxaceae · Dried bark · Tea (decoction), tincture, liquid extract, capsules

An interaction check asks whether these two react with each other — it does not ask whether Cramp Bark is a good idea for someone in your situation. Here is what our Cramp Bark record says about it on its own.

Cramp Bark: dosing

There is no well-established or standardized dose for Cramp Bark. Products vary widely in strength, especially between teas, tinctures, and capsules.The safest approach is to follow the directions on the product label and not exceed them. Because quality and concentration differ between brands, and because little is known about safe long-term use, it is a good idea to review the product with your pharmacist before starting.

From our Cramp Bark monograph — the full record covers uses, side effects and every documented interaction.

Read the full Cramp Bark monograph & all interactions
Medication

About Larotrectinib

What Is Larotrectinib Used For?

Brand name: Vitrakvi

Vitrakvi is used to treat adult and pediatric patients with solid tumors that have a neurotrophic receptor tyrosine kinase (NTRK) gene fusion — a specific genetic alteration that can drive tumor growth. It is used when the tumor is metastatic (has spread) or when surgery to remove it would likely cause serious harm, and when there are no satisfactory alternative treatments or the cancer has continued to grow after prior treatment.

Patients must be selected for Vitrakvi therapy based on an FDA-approved test that confirms the NTRK gene fusion in their tumor. This approval is under the FDA's accelerated approval pathway, based on how many patients responded to treatment and how long those responses lasted. Continued approval may depend on results from follow-up clinical trials.

See full Larotrectinib drug information
Keep checking

Other Drugs & Cramp Bark

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Cramp Bark list.

See the full Cramp Bark interactions page
See every supplement checked against Larotrectinib, ranked by severity
Sources

Sources & How We Checked

We checked Cramp Bark against Larotrectinib in the Natural Medicines interaction database and found no documented interaction on file. The medication overview comes from MedlinePlus, and supplement label details from the NIH Dietary Supplement Label Database.

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
Cramp Bark monograph › Uses, safety, and every drug interaction in one place Larotrectinib supplement interactions › Every supplement checked against Larotrectinib, ranked by severity Larotrectinib 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 Cramp Bark and Larotrectinib Together: Common Questions

Is it safe to take Cramp Bark with Larotrectinib?
We do not list a known interaction between Cramp Bark and Larotrectinib. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Does Larotrectinib interact with any supplements?
Yes. Larotrectinib has documented interactions with 143 supplements in our database — Cramp Bark is not one of them. The Larotrectinib interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Larotrectinib and Cramp Bark?

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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.