Drug & supplement interaction

Boxwood + Gemcitabine

Gemcitabine brand name: Gemzar.

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

We found no known interaction between Boxwood and Gemcitabine 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Boxwood and Gemcitabine

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 Gemcitabine and Boxwood 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.

Boxwood safety at a glance

Boxwood overall Use caution The raw plant is toxic; only processed extracts are used and safety data are limited.
Pregnancy Likely Unsafe When the whole leaf is used orally; avoid using. There is insufficient reliable information available about the safety of boxwood leaf extract when used during... Read the full pregnancy detail
Breastfeeding Likely Unsafe When the whole leaf is used orally; avoid using. There is insufficient reliable information available about the safety of boxwood leaf extract when used during... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Gemcitabine and Boxwood? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Gemcitabine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Gemcitabine is filed under 2 classifications — antineoplastics, hepatotoxic drugs. Boxwood has documented interactions with 2 drug classes — the most serious being anticholinergic drugs (moderate) and cholinergic drugs (moderate) — and none of Gemcitabine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Boxwood Does Interact With Other Medications

Boxwood has 219 moderate known drug interactions in our database — Gemcitabine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 219 No known interaction 2,611 (incl. Gemcitabine)
Taking anything else?

Check Another of Your Medications Against Boxwood

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

What to actually watch for

No Interaction Found — But Data Suggests Boxwood and Gemcitabine May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • A skin rash Additional detail

    Boxwood

    “Orally, boxwood leaf extract seems to be well tolerated. However, ingestion of whole boxwood leaf can cause serious side effects including vomiting, diarrhea, severe colonic spasms, paralysis, and death secondary to asphyxiation (18).

    Topically, the fresh plant and wood can cause allergic contact dermatitis (18, 37073).

    When inhaled, the wood dust can cause rhinoconjunctivitis and bronchitis.”

    Boxwood · Natural Medicines adverse-effect record, reported in acute bronchitis.

    3 sources cited
    1. 5643. Durant J, Chantre P, Gonzalez G, et al. Efficacy and safety of Buxus sempervirens L. preparations (SPV30) in HIV-infected asymptomatic patients: a multicentre, randomized, double-blind, placebo-controlled trial. Phytomedicine 1998;5:1-10. DOI
    2. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    3. 99904. Carballada F, Prat M, Núñez R, et al. Allergy to boxwood. J Investig Allergol Clin Immunol. 2014;24(5):359-61.

    “Occupational exposure to boxwood dust might cause allergic symptoms. In a case report, a 52-year-old male experienced symptoms such as rhinoconjunctivitis and bronchitis following occupational exposure to boxwood wood dust. Cases of allergic contact dermatitis to fresh boxwood leaves and a boxwood recorder have also been reported (18,37073).”

    Boxwood · Natural Medicines adverse-effect record, reported in acute bronchitis.

    3 sources cited
    1. 99904. Carballada F, Prat M, Núñez R, et al. Allergy to boxwood. J Investig Allergol Clin Immunol. 2014;24(5):359-61.
    2. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    3. 37073. van Neer, F. J. and van Ginkel, C. J. Allergic contact dermatitis from a boxwood recorder. Contact Dermatitis 1997;36(6):305.

    Gemcitabine

    Listed in the ADVERSE REACTIONS section of the FDA label for Gemcitabine. Read the label on DailyMed ›

  • Vomiting Additional detail

    Boxwood

    “Orally, ingestion of whole boxwood leaf can cause serious side effects including vomiting, diarrhea, and severe colonic spasms (18). The extract, however, does not seem to have these effects.”

    Boxwood · Natural Medicines adverse-effect record, reported in diarrhea.

    2 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 5643. Durant J, Chantre P, Gonzalez G, et al. Efficacy and safety of Buxus sempervirens L. preparations (SPV30) in HIV-infected asymptomatic patients: a multicentre, randomized, double-blind, placebo-controlled trial. Phytomedicine 1998;5:1-10. DOI

    Gemcitabine

    Listed in the ADVERSE REACTIONS section of the FDA label for Gemcitabine. Read the label on DailyMed ›

Reported for Boxwood but not commonly for Gemcitabine: diarrhea.

Effects for Gemcitabine come from the ADVERSE REACTIONS section of its FDA label; effects for Boxwood come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 53,020 voluntary FDA FAERS reports for Gemcitabine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Boxwood in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When the whole leaf is used orally; avoid using. There is insufficient reliable information available about the safety of boxwood leaf extract when used during pregnancy and lactation; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Gemcitabine

This page covers Boxwood only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Gemcitabine page lists 39 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 3 major · 35 moderate · 1 minor.

Open the Gemcitabine interaction page

One more smart check

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

We hold 7 real supplement products containing Boxwood, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Boxwood. Even though Boxwood itself has no known interaction with Gemcitabine, 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 Boxwood and Gemcitabine 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 Boxwood
Steady interest

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

29 days ago today
Medication Gemcitabine
Steady interest

#2,588 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 Boxwood reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Boxwood and Gemcitabine records this page draws on were last updated July 10, 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 Boxwood

What is Boxwood?

Boxwood
  • HIV/immune support
  • Malaria
  • Arthritis
  • Diabetes
  • Skin conditions
  • Fever

Boxwood is an evergreen shrub whose leaves have been used in folk medicine, most notably in some early studies looking at HIV. The whole plant is toxic, so only processed extracts are used, and solid evidence for any health benefit is very limited. Because of real safety concerns, talk with a pharmacist or doctor before trying boxwood.

Buxus sempervirens · Buxaceae · Leaves (processed into extracts) · Capsules, liquid extracts, tinctures

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

Boxwood: dosing

There is no well-established or standardized dose of boxwood for any condition. The strength and quality of commercial extracts can vary a lot from product to product.If you choose to use a boxwood product, follow the directions on the label and do not exceed them. Never use leaves or material from garden boxwood, since the raw plant is toxic.

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

Read the full Boxwood monograph & all interactions
Medication

About Gemcitabine Injection

What Is Gemcitabine Injection Used For?

Brand name: Gemzar

Gemcitabine Injection (available as Avgemsi, Gemcitabine, and Infugem) is used to treat several types of cancer. It is given in combination with carboplatin for advanced ovarian cancer that has returned at least 6 months after platinum-based treatment, and in combination with paclitaxel as a first-line treatment for metastatic breast cancer after prior chemotherapy with an anthracycline (a specific class of chemo drug).

It is also given in combination with cisplatin for non-small cell lung cancer (NSCLC) that cannot be removed surgically or has spread. For pancreatic cancer that is locally advanced or has spread, it is used as a single agent — including in patients who have already been treated with fluorouracil.

Most-Reported Side Effects for Gemcitabine

From FAERS, the FDA’s public side-effect reporting system (53,020 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Disease progression 4,850 reports
Thrombocytopenia 3,706 reports
Neutropenia 3,295 reports
Anemia 3,084 reports
Malignant neoplasm progression 2,912 reports
See full Gemcitabine Injection drug information
Keep checking

Other Drugs & Boxwood

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

0Major
219Moderate
0Minor
2,610No known interaction
219 Moderate 2,610 No interaction
Moderate

219 interactions

Showing 60 of 219 moderate interactions — see all 219 on the Boxwood page.

No interaction 2,610 drugs checked — show the list

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

Showing the 60 most looked-up of 2,610 medications checked with no known interaction — see the full Boxwood list.

See the full Boxwood interactions page
See every supplement checked against Gemcitabine, ranked by severity
Evidence & sources

Boxwood References

The 6 references that drive our Boxwood 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. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Durant J, Chantre P, Gonzalez G, et al. Efficacy and safety of Buxus sempervirens L. preparations (SPV30) in HIV-infected asymptomatic patients: a multicentre, randomized, double-blind, placebo-controlled trial. Phytomedicine 1998;5:1-10. DOI
  4. Orhan, I., Sener, B., Choudhary, M. I., and Khalid, A. Acetylcholinesterase and butyrylcholinesterase inhibitory activity of some Turkish medicinal plants. J Ethnopharmacol 2004;91(1):57-60. PubMed
  5. van Neer, F. J. and van Ginkel, C. J. Allergic contact dermatitis from a boxwood recorder. Contact Dermatitis 1997;36(6):305.
  6. Carballada F, Prat M, Núñez R, et al. Allergy to boxwood. J Investig Allergol Clin Immunol. 2014;24(5):359-61.

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 Boxwood and Gemcitabine Together: Common Questions

Is it safe to take Boxwood with Gemcitabine?
We do not list a known interaction between Boxwood and Gemcitabine. 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.
Do Boxwood and Gemcitabine have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Boxwood and Gemcitabine combination checked?
Interactions in our licensed database are recorded against drug classes. Gemcitabine is filed under 2 classifications, and Boxwood has documented interactions with 2 drug classes — none of Gemcitabine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Boxwood interact with any other medications?
Yes. Boxwood has 219 documented drug interactions in our database — Gemcitabine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Gemcitabine interact with any supplements?
Yes. Gemcitabine has documented interactions with 39 supplements in our database — Boxwood is not one of them. The Gemcitabine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Boxwood monograph Uses, safety profile, and every drug interaction in one place Gemcitabine Injection drug information The full plain-English guide to this medication Gemcitabine supplement interactions Every supplement checked against Gemcitabine, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 6 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Gemcitabine and Boxwood?

Our pharmacists answer your medication & supplement questions — free.

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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.