Drug & supplement interaction

Marshmallow + Levoleucovorin

Levoleucovorin brand name: Khapzory.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Marshmallow and Levoleucovorin 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

Marshmallow and Levoleucovorin

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 Levoleucovorin and Marshmallow 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.

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.

Marshmallow safety at a glance

Marshmallow overall Use caution Generally well tolerated for short-term use, but human safety data are limited.
Pregnancy Avoid Not enough reliable safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Not enough reliable safety information, so it is best avoided while breastfeeding.

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

Still wondering about combining Levoleucovorin and Marshmallow? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Keep it in perspective

Marshmallow Does Interact With Other Medications

Marshmallow has 1 moderate, 2,039 minor known drug interactions in our database — Levoleucovorin isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Marshmallow

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

What to actually watch for

What Levoleucovorin’s Own FDA Label Lists

This is not an interaction — none of it involves Marshmallow. These are the most notable effects listed in the ADVERSE REACTIONS section of Levoleucovorin’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. 5 of them are worth acting on rather than waiting out — marked below.

  • A low white blood cell count Worth acting on mentioned in 6.8% of FDA reports for Levoleucovorin
  • Confusion Worth acting on
  • A low platelet count Worth acting on
  • Shortness of breath Worth acting on
  • An allergic reaction Worth acting on
  • Mouth irritation or sores
  • Hair loss
  • Reduced appetite mentioned in 5.0% of FDA reports for Levoleucovorin
  • Stomach upset
  • Itching

Showing the 10 most notable of 16 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 Levoleucovorin. Read the label on DailyMed › Where a percentage is shown, it is the share of 3,706 voluntary FDA FAERS reports for Levoleucovorin that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Marshmallow’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Marshmallow side to compare — that is a limit of the record, not a statement that Marshmallow has no side effects.

One more smart check

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

We hold 1,622 real supplement products containing Marshmallow, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Marshmallow. Even though Marshmallow itself has no known interaction with Levoleucovorin, 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 Marshmallow and Levoleucovorin 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 Marshmallow
Top 10%

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

29 days ago today
Medication Levoleucovorin
Steady interest

#2,347 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. See every Marshmallow reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Marshmallow and Levoleucovorin 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 Marshmallow

What is Marshmallow?

Marshmallow
  • Cough and sore throat
  • Dry mouth and throat irritation
  • Digestive upset and heartburn
  • Skin irritation
  • Soothing inflamed tissue

Marshmallow root is a traditional herb rich in soothing, gel-like fibers called mucilage, which is why it has long been used for coughs, sore throats, and stomach irritation. Evidence for these uses is mostly traditional and preliminary, but it is generally considered gentle and well-tolerated for short-term use. As with any supplement, check with your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or taking other medicines.

Althaea officinalis · Malvaceae · Root and leaves · Tea, capsules, tinctures, syrups, lozenges, dried root, topical creams

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

Marshmallow: dosing

There is no official, standardized dose for marshmallow. The right amount depends on the form (tea, capsule, syrup, lozenge, or tincture) and the specific product.The safest approach is to follow the directions on the product label and not exceed the recommended amount. For teas, the dried root is often steeped in water; for other forms, the manufacturer's instructions should guide you.When taking marshmallow as a capsule or tincture, it is often recommended to drink plenty of water.

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

Read the full Marshmallow monograph & all interactions
Medication

About Levoleucovorin Injection

What Is Levoleucovorin Injection Used For?

Brand name: Khapzory

Levoleucovorin injection (brands: Fusilev, Khapzory) is used intravenously in three main situations. First, it is given as a "rescue" treatment after high-dose methotrexate chemotherapy in osteosarcoma (bone cancer) — helping to limit the toxic effects methotrexate can have on healthy cells. Second, it is used when methotrexate is not clearing the body fast enough, or when there has been an accidental overdose of methotrexate or similar drugs called folic acid antagonists.

Third, levoleucovorin injection is used alongside the chemotherapy drug 5-fluorouracil (5-FU) for the palliative treatment of advanced metastatic colorectal cancer — meaning it helps make 5-FU work better, though the goal is disease control rather than cure. It is not approved for pernicious anemia or megaloblastic anemias related to vitamin B12 deficiency.

Most-Reported Side Effects for Levoleucovorin

From FAERS, the FDA’s public side-effect reporting system (3,706 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Nausea 288 reports
Neutropenia 251 reports
Diarrhea 246 reports
Decreased appetite 187 reports
Vomiting 171 reports
See full Levoleucovorin Injection drug information
Keep checking

Other Drugs & Marshmallow

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

0Major
1Moderate
2,039Minor
789No known interaction
Moderate

1 interaction

Minor

2,039 interactions

Showing 60 of 2,039 minor interactions — see all 2,039 on the Marshmallow page.

No interaction 789 drugs checked — show the list

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

Showing the 60 most looked-up of 789 medications checked with no known interaction — see the full Marshmallow list.

Evidence & sources

Marshmallow References

The 5 references that drive our Marshmallow monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Monographs on the medicinal uses of plant drugs. Exeter, UK: European Scientific Co-op Phytother, 1997.
  2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  3. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  4. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  5. Hage-Sleiman R, Mroueh M, Daher CF. Pharmacological evaluation of aqueous extract of Althaea officinalis flower grown in Lebanon. Pharm Biol 2011;49(3):327-33.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Marshmallow and Levoleucovorin Together: Common Questions

Is it safe to take Marshmallow with Levoleucovorin?
We do not list a known interaction between Marshmallow and Levoleucovorin. 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 Marshmallow interact with any other medications?
Yes. Marshmallow has 2,040 documented drug interactions in our database — Levoleucovorin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

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

Still Have a Question About Levoleucovorin and Marshmallow?

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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.