Drug & supplement interaction

Canadian Fleabane + Isoniazid

Isoniazid brand names: Laniazid, INH, Nydrazid.

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 Canadian Fleabane and Isoniazid 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

Canadian Fleabane and Isoniazid

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 Isoniazid and Canadian Fleabane 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.

Canadian Fleabane safety at a glance

Canadian Fleabane overall Use caution Used traditionally, but human safety data are limited so use cautiously.
Pregnancy Avoid Not enough safety information, so avoid use during pregnancy.
Breastfeeding Avoid Not enough safety information, so avoid use while breastfeeding.

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

Still wondering about combining Isoniazid and Canadian Fleabane? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Isoniazid

Interactions in our licensed database are recorded against drug classes, not just single drug names. Isoniazid is filed under 8 classifications — including cytochrome p450 2c19 (cyp2c19) inhibitors, cytochrome p450 2c9 (cyp2c9) inhibitors, cytochrome p450 1a2 (cyp1a2) inhibitors. Canadian Fleabane has documented interactions with 1 drug class — the most serious being anticoagulant/antiplatelet drugs (moderate) — and none of Isoniazid’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

Canadian Fleabane Does Interact With Other Medications

Canadian Fleabane has 122 moderate known drug interactions in our database — Isoniazid isn’t one of them. If you take anything else, check it against the full list below.

Moderate 122 No known interaction 2,708 (incl. Isoniazid)
Taking anything else?

Check Another of Your Medications Against Canadian Fleabane

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

What to actually watch for

What Isoniazid’s Own FDA Label Lists

This is not an interaction — none of it involves Canadian Fleabane. These are the most notable effects listed in the ADVERSE REACTIONS section of Isoniazid’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
  • Unsteadiness Worth acting on
  • A severe skin reaction Worth acting on mentioned in 4.6% of FDA reports for Isoniazid
  • Hallucinations Worth acting on
  • Pancreatitis Worth acting on
  • Yellowing of the skin or eyes Worth acting on
  • High blood sugar Worth acting on
  • Seizures Worth acting on
  • Liver problems Worth acting on mentioned in 5.4% of FDA reports for Isoniazid
  • A low platelet count Worth acting on

Showing the 10 most notable of 21 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 Isoniazid. Read the label on DailyMed › Where a percentage is shown, it is the share of 16,103 voluntary FDA FAERS reports for Isoniazid that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Canadian Fleabane’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Canadian Fleabane side to compare — that is a limit of the record, not a statement that Canadian Fleabane has no side effects.

From our Q&A

Questions About Canadian Fleabane or Isoniazid

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

This page covers Canadian Fleabane only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Isoniazid page lists 84 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Adrafinil (moderate).

By severity: 4 major · 67 moderate · 13 minor.

From our pharmacist’s overview on the Isoniazid page

“The liver does most of the worrying here. Isoniazid, a backbone of tuberculosis treatment, is already hard on the liver by itself, and 38 of the supplements on this list can add strain, from Siberian cocklebur, a major-rated entry, to everyday herbs like ashwagandha and black cohosh.”

Reviewed by 2 · Jul 18, 2026

Open the Isoniazid interaction page

How much people look this up

Where Canadian Fleabane and Isoniazid 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 Canadian Fleabane
Top half

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

29 days ago today
Medication Isoniazid
Steady interest

#1,802 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 Canadian Fleabane reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Canadian Fleabane and Isoniazid 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 Canadian Fleabane

What is Canadian Fleabane?

  • Diarrhea
  • Minor bleeding
  • Urinary complaints
  • Digestive upset
  • Sore throat and inflammation

Canadian Fleabane is a common North American weed used in traditional medicine for diarrhea, minor bleeding, and urinary issues, but high-quality human studies are lacking. Because its safety has not been well studied, it is best to talk with your pharmacist or doctor before using it, and to avoid it during pregnancy and breastfeeding.

Erigeron canadensis · Asteraceae · Aerial parts (leaves, stems, flowers) and the essential oil · Tea, tincture, dried herb, liquid extract, essential oil

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

Canadian Fleabane: dosing

There is no established, science-based standard dose for Canadian Fleabane. Traditional preparations such as teas and tinctures vary widely in strength, and product labels differ from brand to brand.If you choose to use a commercial product, follow the directions on the label and do not exceed them. The essential oil is very concentrated and is not meant to be taken by mouth without professional guidance.

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

Read the full Canadian Fleabane monograph & all interactions
Medication

About Isoniazid

What Is Isoniazid Used For?

Brand names: Laniazid, INH, Nydrazid

Isoniazid is used to treat all forms of tuberculosis (TB) caused by susceptible bacteria. Because TB bacteria can quickly become resistant to a single drug, isoniazid must always be combined with other anti-TB medications when treating active TB — it is never used alone for active disease.

Isoniazid is also used as preventive therapy (sometimes called latent TB treatment) for people who have a positive TB skin test but do not yet have active disease. This includes people with HIV infection, close contacts of someone with active TB, recent TB skin test converters, and people with certain medical conditions — such as silicosis, diabetes mellitus, end-stage renal disease, leukemia, or Hodgkin's disease — that raise their TB risk.

Most-Reported Side Effects for Isoniazid

From FAERS, the FDA’s public side-effect reporting system (16,103 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fever 1,102 reports
Nausea 903 reports
Drug-induced liver injury 862 reports
Drug reaction with eosinophilia and systemic symptoms 744 reports
Vomiting 637 reports
See full Isoniazid drug information
Keep checking

Other Drugs & Canadian Fleabane

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

0Major
122Moderate
0Minor
2,707No known interaction
122 Moderate 2,707 No interaction
Moderate

122 interactions

Showing 60 of 122 moderate interactions — see all 122 on the Canadian Fleabane page.

No interaction 2,707 drugs checked — show the list

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

Showing the 60 most looked-up of 2,707 medications checked with no known interaction — see the full Canadian Fleabane list.

See the full Canadian Fleabane interactions page
See every supplement checked against Isoniazid, ranked by severity
Evidence & sources

Canadian Fleabane References

The 2 references that drive our Canadian Fleabane 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. Saluk-Juszczak J, Olas B, Pawlaczyk I, Gancarz R, Wachowicz B. Effects of the extract from Conyza canadensis on human blood platelet aggregation. Gen Physiol Biophys 2007;26(2):150-2.
  2. Olas B, Saluk-Juszczak J, Pawlaczyk I, et al. Antioxidant and antiaggregatory effects of an extract from Conyza canadensis on blood platelets in vitro. Platelets 2006;17(6):354-60.

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 Canadian Fleabane and Isoniazid Together: Common Questions

Is it safe to take Canadian Fleabane with Isoniazid?
We do not list a known interaction between Canadian Fleabane and Isoniazid. 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.
How was the Canadian Fleabane and Isoniazid combination checked?
Interactions in our licensed database are recorded against drug classes. Isoniazid is filed under 8 classifications, and Canadian Fleabane has documented interactions with 1 drug class — none of Isoniazid'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 Canadian Fleabane interact with any other medications?
Yes. Canadian Fleabane has 122 documented drug interactions in our database — Isoniazid 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 Isoniazid interact with any supplements?
Yes. Isoniazid has documented interactions with 84 supplements in our database — Canadian Fleabane is not one of them. The Isoniazid 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

Canadian Fleabane monograph Uses, safety profile, and every drug interaction in one place Isoniazid drug information The full plain-English guide to this medication Isoniazid supplement interactions Every supplement checked against Isoniazid, 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 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Isoniazid and Canadian Fleabane?

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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.