Drug & supplement interaction

Nasturtium + Cephalexin

Cephalexin brand names: Keflex, Keftab, Cephalex, Lexin.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Nasturtium and Cephalexin 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

Nasturtium and Cephalexin

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 Cephalexin and Nasturtium 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 Nasturtium at all — not against Cephalexin, 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.

Nasturtium safety at a glance

Nasturtium overall Use caution Generally considered safe as a food, but concentrated extracts have limited safety data.
Pregnancy Avoid Not enough safety information; medicinal amounts are best avoided during pregnancy.
Breastfeeding Use caution Safety during breastfeeding is not well studied, so caution is advised.

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

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

What Nasturtium Itself Has Been Linked To

This is not an interaction — nothing below involves Cephalexin. It is the side-effect record for Nasturtium on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Nasturtium, this list is the first place to look.

  • A skin rash Additional detail

    “Orally, large amounts of nasturtium or benzyl mustard oil, a constituent of nasturtium, can cause gastrointestinal tract irritation (2,18). Large amounts of nasturtium can cause albuminuria due to glomerular and tubular damage (2).

    Topically, contact with the nasturtium plant and its benzyl mustard oil constituent can cause skin and mucosal irritation (2,18).”

    Nasturtium · Natural Medicines adverse-effect record, reported in albuminuria.

    3 sources cited
    1. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    2. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    3. 99386. Perez-Crespo M, Silvestre JF, Mataix J, Ballester I, Toledo F, Betlloch I. Contact dermatitis due to nasturtium. Contact Dermatitis. 2009;60(4):229-30. PubMed

    “Topically, contact with the nasturtium plant and its benzyl mustard oil constituent can cause skin and mucosal irritation (2,18). Benzyl mustard oil is a contact allergen if applied to the skin. There are multiple case reports of contact dermatitis attributed to nasturtium.”

    Nasturtium · Natural Medicines adverse-effect record, reported in dermatitis.

    3 sources cited
    1. 2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
    2. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    3. 99386. Perez-Crespo M, Silvestre JF, Mataix J, Ballester I, Toledo F, Betlloch I. Contact dermatitis due to nasturtium. Contact Dermatitis. 2009;60(4):229-30. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Nasturtium — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Cephalexin’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Cephalexin column appears here.

Overlapping uses

What Cephalexin Is Prescribed For, and What Nasturtium Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Cephalexin is a prescription medicine with approved uses on its FDA label. Nasturtium is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Cephalexin is prescribed for: Cephalexin treats bacterial infections caused by susceptible strains of bacteria. It is used for respiratory tract infections, ear infections (otitis media), skin and skin structure infections, bone infections, and genitourinary tract infections — including acute prostatitis. It works only against bacterial infections — not viruses like colds or flu. Your prescriber should use it only when a bacterial infection is confirmed or strongly suspected, to help prevent antibiotic resistance.

Nasturtium has been studied for:

  • Respiratory tract infections studied, not established Nasturtium has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Nasturtium for respiratory tract infections

    Preliminary clinical research in patients with a history of recurrent respiratory tract infections (RTIs) shows that taking a specific combination product (Angocin Anti-Infekt N, Repha GmbH) containing a total of 320-400 mg horseradish root and 800-1000 mg nasturtium daily for 12 weeks modestly decreases the rate of new RTIs when compared with placebo.

    1 source cited
    1. 96309. Fintelmann V, Albrecht U, Schmitz G, Schnitker J. Efficacy and safety of a combination herbal medicinal product containing Tropaeoli majoris herba and Armoraciae rusticanae radix for the prophylactic treatment of patients with respiratory tract diseases:

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Cephalexin on your own; if you are taking Nasturtium for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Nasturtium or Cephalexin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Nasturtium or Cephalexin, 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 Cephalexin

This page covers Nasturtium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cephalexin page lists 61 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate) and Aristolochia (moderate).

By severity: 3 major · 47 moderate · 11 minor.

From our pharmacist’s overview on the Cephalexin page

“Cephalexin (Keflex) is one of the most commonly prescribed oral antibiotics, usually for skin and urinary infections, and its supplement list warrants genuine care rather than a quick skim. Three of the 61 ingredients on file rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Cephalexin interaction page

One more smart check

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

We hold 3 real supplement products containing Nasturtium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Nasturtium. Even though Nasturtium itself has no known interaction with Cephalexin, 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 Nasturtium and Cephalexin 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 Nasturtium
Top half

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

29 days ago today
Medication Cephalexin
Top 5%

#107 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 Nasturtium reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Nasturtium and Cephalexin 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 Nasturtium

What is Nasturtium?

  • Urinary tract infections
  • Respiratory infections and congestion
  • Antimicrobial support
  • Wound and skin care (topical)
  • Mild cold and cough symptoms

Nasturtium is an edible garden plant traditionally used for urinary and respiratory infections, often combined with horseradish in herbal products. Some lab studies suggest it has antimicrobial activity, but high-quality human evidence is limited. Talk with your pharmacist or doctor before using it, especially if you are pregnant, breastfeeding, or have kidney or stomach problems.

Tropaeolum majus · Tropaeolaceae · Leaves, flowers, and seeds · Fresh leaves and flowers (food/salad), dried herb, tea, capsules, tinctures, and combination herbal products

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

Nasturtium: dosing

There is no well-established standardized dose for nasturtium. Amounts vary widely depending on whether you use fresh leaves, dried herb, tea, capsules, or a combination product.The best approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Nasturtium monograph & all interactions
Medication

About Cephalexin

What Is Cephalexin Used For?

Brand names: Keflex, Keftab, Cephalex, Lexin

Cephalexin treats bacterial infections caused by susceptible strains of bacteria. It is used for respiratory tract infections, ear infections (otitis media), skin and skin structure infections, bone infections, and genitourinary tract infections — including acute prostatitis.

It works only against bacterial infections — not viruses like colds or flu. Your prescriber should use it only when a bacterial infection is confirmed or strongly suspected, to help prevent antibiotic resistance.

Most-Reported Side Effects for Cephalexin

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Chronic kidney disease 2,157 reports
Renal failure 1,558 reports
Acute kidney injury 1,550 reports
Diarrhea 1,405 reports
Fatigue 1,303 reports
See full Cephalexin drug information
Keep checking

Other Drugs & Nasturtium

Browse every other medication we’ve checked against Nasturtium — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Nasturtium References

The 5 references that drive our Nasturtium 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. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Fintelmann V, Albrecht U, Schmitz G, Schnitker J. Efficacy and safety of a combination herbal medicinal product containing Tropaeoli majoris herba and Armoraciae rusticanae radix for the prophylactic treatment of patients with respiratory tract diseases:
  4. Albrecht U, Goos KH, Schneider B. A randomised, double-blind, placebo-controlled trial of a herbal medicinal product containing Tropaeoli majoris herba (Nasturtium) and Armoraciae rusticanae radix (Horseradish) for the prophylactic treatment of patients w
  5. Perez-Crespo M, Silvestre JF, Mataix J, Ballester I, Toledo F, Betlloch I. Contact dermatitis due to nasturtium. Contact Dermatitis. 2009;60(4):229-30. PubMed

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 Nasturtium and Cephalexin Together: Common Questions

Is it safe to take Nasturtium with Cephalexin?
We do not list a known interaction between Nasturtium and Cephalexin. 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.
Are Nasturtium and Cephalexin used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Nasturtium in each. That is a conversation for your prescriber, especially if Cephalexin is being adjusted to a target.
Does Cephalexin interact with any supplements?
Yes. Cephalexin has documented interactions with 61 supplements in our database — Nasturtium is not one of them. The Cephalexin 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 Cephalexin and Nasturtium?

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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.