Drug & supplement interaction

Elderflower + Isoniazid

Isoniazid brand names: Laniazid, INH, Nydrazid.

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 Elderflower 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

Elderflower 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 Elderflower 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.

Elderflower safety at a glance

Elderflower overall Use caution Properly prepared flowers are generally well tolerated, but raw plant parts can be toxic.
Pregnancy Avoid There is not enough reliable safety information, so it is best to avoid.
Breastfeeding Avoid Safety has not been studied, so avoid unless your doctor approves.

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

Still wondering about combining Isoniazid and Elderflower? 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. Elderflower has documented interactions with 1 drug class — the most serious being antidiabetes 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

Elderflower Does Interact With Other Medications

Elderflower has 86 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 86 No known interaction 2,744 (incl. Isoniazid)
Taking anything else?

Check Another of Your Medications Against Elderflower

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

What to actually watch for

What Elderflower Itself Has Been Linked To

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

  • Diarrhea Additional detail

    “Diarrhea and colic have been reported after drinking a tea made from elderflower, anise fruit, fennel fruit, and senna flowers. It is not clear if these effects were due to elderflower or the other ingredients.”

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

    1 source cited
    1. 49494. Picon, P. D., Picon, R. V., Costa, A. F., Sander, G. B., Amaral, K. M., Aboy, A. L., and Henriques, A. T. Randomized clinical trial of a phytotherapic compound containing Pimpinella anisum, Foeniculum vulgare, Sambucus nigra, and Cassia augustifolia for

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

Overlapping uses

What Isoniazid Is Prescribed For, and What Elderflower Has Been Studied For

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

Isoniazid is prescribed for: 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.

Elderflower has been studied for:

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

    Elderflower for diabetes

    Although there has been interest in using oral elderflower for diabetes, there is insufficient reliable information about the clinical effects of elderflower for this purpose.

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 Isoniazid on your own; if you are taking Elderflower for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Elderflower 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 Elderflower 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 Elderflower 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 Elderflower 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 Elderflower
Steady interest

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

29 days ago today
Medication Isoniazid
Steady interest

#2,422 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 Elderflower reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Elderflower and Isoniazid 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 Elderflower

What is Elderflower?

  • Colds and flu
  • Sinus congestion
  • Fever and sweating
  • Sore throat
  • Coughs

Elderflower comes from the elder plant (Sambucus nigra) and is traditionally used as a tea or extract for colds, sinus congestion, and fever. Good-quality human evidence is limited, so it should be seen as a soothing traditional remedy rather than a proven treatment. Raw or unripe parts of the plant can be toxic, so use only properly prepared products, and check with your pharmacist or doctor first.

Sambucus nigra · Adoxaceae · Dried flowers · Tea, liquid extract, tincture, capsules, syrups, lozenges

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

Elderflower: dosing

There is no official standardized dose for elderflower. The right amount depends on the product, its strength, and how it is prepared (tea, extract, or tincture).The safest approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Elderflower 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 & Elderflower

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Elderflower page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Elderflower list.

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

Elderflower References

The 2 references that drive our Elderflower 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. Gray AM, Abdel-Wahab YH, Flatt PR. The traditional plant treatment, Sambucus nigra (elder), exhibits insulin-like and insulin-releasing actions in vitro. J Nutr 2000;130:15-20. PubMed
  2. Picon, P. D., Picon, R. V., Costa, A. F., Sander, G. B., Amaral, K. M., Aboy, A. L., and Henriques, A. T. Randomized clinical trial of a phytotherapic compound containing Pimpinella anisum, Foeniculum vulgare, Sambucus nigra, and Cassia augustifolia for

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 Elderflower and Isoniazid Together: Common Questions

Is it safe to take Elderflower with Isoniazid?
We do not list a known interaction between Elderflower 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.
Are Elderflower and Isoniazid 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 Elderflower in each. That is a conversation for your prescriber, especially if Isoniazid is being adjusted to a target.
How was the Elderflower and Isoniazid combination checked?
Interactions in our licensed database are recorded against drug classes. Isoniazid is filed under 8 classifications, and Elderflower 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 Elderflower interact with any other medications?
Yes. Elderflower has 86 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 — Elderflower 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

Elderflower 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 Elderflower?

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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.