Drug & supplement interaction

Asarabacca + Cephalexin

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

Major Interaction
Medically reviewed by · Updated February 2024
The bottom line Major

Asarabacca has a major interaction with Cephalexin. Asarabacca, a herbaceous plant, is often contaminated with aristolochic acid, a compound known for its nephrotoxic effects.

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

Asarabacca and Cephalexin

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

Major

Nephrotoxic Drugs

Why this applies to Cephalexin

Cephalexin falls under Nephrotoxic Drugs — the group Asarabacca interacts with.

Asarabacca, a herbaceous plant, is often contaminated with aristolochic acid, a compound known for its nephrotoxic effects. Aristolochic acid can damage the kidneys and is deemed unsafe by the FDA, leading to the classification of products containing it as adulterated. When considering medications that may also pose a risk of kidney damage, caution is advised when combining them with asarabacca due to potential additive nephrotoxicity. It is advisable to consult healthcare professionals before using asarabacca alongside nephrotoxic drugs to minimize the risk of adverse effects on kidney function.
Severity Major Likelihood Possible Evidence C

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 concern with mixing asarabacca and cephalexin (Keflex). This isn't about one changing how the other is broken down. Instead, it's about doubling up on kidney stress. Asarabacca often carries aristolochic acid, a substance known to harm the kidneys. Cephalexin is mostly cleared out through your kidneys and, in rare cases, can irritate them too. Put them together and you may add risk on top of risk.

To be honest, I wouldn't recommend asarabacca at all because of its aristolochic acid problem. Watch for warning signs like less urine, swollen ankles, or unusual tiredness, and please check with your pharmacist or doctor before combining these.

Contact Dr. Brian directly if you have additional questions on this interaction

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

Asarabacca Also Interacts With Other Medications

Asarabacca has 354 major, known drug interactions in our database — the Cephalexin one above is one of them. If you take anything else, check it against the full list below.

Major 354 No known interaction 2,476 (incl. Cephalexin)
Taking anything else?

Check Another of Your Medications Against Asarabacca

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

From our Q&A

Questions About Asarabacca 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 Asarabacca 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 Asarabacca 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), Siberian Cocklebur (major), African Wild Potato (moderate), Aristolochia (moderate) and Bacillus Coagulans (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 Asarabacca as Part of a Dietary Supplement Product? Check It for Interactions

We hold 2 real supplement products containing Asarabacca, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Asarabacca. Your product may carry other ingredients that interact with Cephalexin too, on top of Asarabacca — 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 Asarabacca 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 Asarabacca
Top half

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

29 days ago today
Medication Cephalexin
Top 5%

#64 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 Asarabacca

What is Asarabacca?

Asarabacca
  • Sinus and nasal congestion
  • Coughs and bronchial complaints
  • Inducing sweating
  • Inducing vomiting (emetic)
  • Digestive upset

Asarabacca is a European woodland plant traditionally used to clear the nose, cause sweating, or trigger vomiting, but it is rarely used today. It belongs to a plant family that often contains aristolochic acid, a substance the FDA considers unsafe because it can cause serious kidney damage and cancer, so we do not recommend using it.

Read the full Asarabacca 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.

See full Cephalexin drug information
Keep checking

Other Drugs & Asarabacca

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

354Major
0Moderate
0Minor
2,475No known interaction
354 Major 2,475 No interaction
Major

354 interactions

Showing 60 of 354 major interactions — see all 354 on the Asarabacca page.

No interaction 2,475 drugs checked — show the list

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

Showing the 60 most looked-up of 2,475 medications checked with no known interaction — see the full Asarabacca list.

See the full Asarabacca interactions page
See every supplement checked against Cephalexin, 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
Asarabacca monograph › Uses, safety, and every drug interaction in one place Cephalexin supplement interactions › Every supplement checked against Cephalexin, ranked by severity Cephalexin 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 Asarabacca and Cephalexin Together: Common Questions

Can you take Asarabacca with Cephalexin?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Asarabacca and Cephalexin interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Cephalexin and Asarabacca?

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.