Drug & supplement interaction

Fructo-oligosaccharides (fos) + Isoniazid

Isoniazid brand names: Laniazid, INH, Nydrazid.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Fructo-oligosaccharides (fos) 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

Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos) at all — not against Isoniazid, 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.

Fructo-oligosaccharides (fos) safety at a glance

Fructo-oligosaccha... overall Use caution Generally well tolerated in food amounts but can cause gas and bloating, especially at higher doses.
Pregnancy Use caution Likely fine in normal food amounts, but supplement-level doses are not well studied, so check with your doctor.
Breastfeeding Use caution Limited safety data for supplement use, so use only with professional guidance.

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

Still wondering about combining Isoniazid and Fructo-oligosaccharides (fos)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Fructo-oligosaccharides (fos) Itself Has Been Linked To

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

  • Bloating or gas / Stomach pain Additional detail

    “Orally, FOS may cause flatulence, belching, abdominal pain, intestinal sounds, constipation, and bloating. These symptoms can occur commonly in some patients, but are generally mild at doses under 10 grams per day.”

    Fructo-oligosaccharides (fos) · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 745. Briet F, et al. Symptomatic response to varying levels of fructo-oligosaccharides consumed occasionally or regularly. Eur J Clin Nutr 1995;49:501-7.
    2. 750. Bouhnik Y, Vahedi K, Achour L, et al. Short-chain fructo-oligosaccharide administration dose-dependently increases fecal bifidobacteria in healthy humans. J Nutr 1999;129:113-6. PubMed
    3. 8509. Cummings JH, Macfarlane GT, Englyst HN. Prebiotic digestion and fermentation. Am J Clin Nutr 2001;73:415S-420S. PubMed
    4. 98651. Souza DDS, Tahan S, Weber TK, Araujo-Filho HB, de Morais MB. Randomized, double-blind, placebo-controlled parallel clinical trial assessing the effect of fructooligosaccharides in infants with constipation. Nutrients. 2018;10(11). pii: E1602. PubMed
    5. 107931. Andermann TM, Fouladi F, Tamburini FB, et al. A Fructo-Oligosaccharide Prebiotic Is Well Tolerated in Adults Undergoing Allogeneic Hematopoietic Stem Cell Transplantation: A Phase I Dose-Escalation Trial. Transplant Cell Ther 2021;27(11):932. PubMed
    6. 110710. Dou Y, Yu X, Luo Y, Chen B, Ma D, Zhu J. Effect of Fructooligosaccharides Supplementation on the Gut Microbiota in Human: A Systematic Review and Meta-Analysis. Nutrients 2022;14(16):3298. PubMed
  • Constipation Additional detail

    Recorded for Fructo-oligosaccharides (fos) in the same Natural Medicines adverse-effect record shown under Bloating or gas / Stomach pain above.

Everything above comes from the Natural Medicines adverse-effect record for Fructo-oligosaccharides (fos) — 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 Fructo-oligosaccharides (fos) 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. Fructo-oligosaccharides (fos) 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.

Fructo-oligosaccharides (fos) has been studied for:

  • Diabetes studied, not established Fructo-oligosaccharides (fos) has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Fructo-oligosaccharides (fos) for diabetes

    Oral FOS has only been evaluated in combination with probiotics; its effect when used alone is unclear.

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 Fructo-oligosaccharides (fos) for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos) 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

One more smart check

Taking Fructo-oligosaccharides (fos) as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,251 real supplement products containing Fructo-oligosaccharides (fos), each one broken down to its full ingredient list — and combination products often carry several ingredients besides Fructo-oligosaccharides (fos). Even though Fructo-oligosaccharides (fos) itself has no known interaction with Isoniazid, 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 Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos)
Top 25%

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

29 days ago today
Medication Isoniazid
Steady interest

#1,689 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 Fructo-oligosaccharides (fos) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos)

What is Fructo-oligosaccharides (fos)?

  • Digestive and gut health
  • Prebiotic to support good bacteria
  • Constipation relief
  • Calcium absorption support
  • Blood sugar and appetite support

Fructo-oligosaccharides (FOS) are a type of soluble fiber that acts as a prebiotic, meaning they feed the helpful bacteria in your gut. They are generally considered safe for most people in normal food amounts, but higher doses commonly cause gas and bloating. Evidence for many health claims is still limited, so talk with your pharmacist or doctor before using FOS supplements.

Carbohydrate fibers extracted from plants such as chicory root, or made by enzymatic processing of sugars · Powders, capsules, syrups, added to foods and infant formulas, and combined with probiotics in synbiotic products

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

Fructo-oligosaccharides (fos): dosing

There is no single official or standardized dose of FOS. Amounts used in studies and products vary widely, often given as a few grams of fiber per day.Because higher amounts increase the risk of gas and bloating, it is best to start low and increase gradually if needed.

From our Fructo-oligosaccharides (fos) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Fructo-oligosaccharides (fos) 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 & Fructo-oligosaccharides (fos)

Browse every other medication we’ve checked against Fructo-oligosaccharides (fos) — 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

Fructo-oligosaccharides (fos) References

The 6 references that drive our Fructo-oligosaccharides (fos) 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. Briet F, et al. Symptomatic response to varying levels of fructo-oligosaccharides consumed occasionally or regularly. Eur J Clin Nutr 1995;49:501-7.
  2. Bouhnik Y, Vahedi K, Achour L, et al. Short-chain fructo-oligosaccharide administration dose-dependently increases fecal bifidobacteria in healthy humans. J Nutr 1999;129:113-6. PubMed
  3. Cummings JH, Macfarlane GT, Englyst HN. Prebiotic digestion and fermentation. Am J Clin Nutr 2001;73:415S-420S. PubMed
  4. Souza DDS, Tahan S, Weber TK, Araujo-Filho HB, de Morais MB. Randomized, double-blind, placebo-controlled parallel clinical trial assessing the effect of fructooligosaccharides in infants with constipation. Nutrients. 2018;10(11). pii: E1602. PubMed
  5. Andermann TM, Fouladi F, Tamburini FB, et al. A Fructo-Oligosaccharide Prebiotic Is Well Tolerated in Adults Undergoing Allogeneic Hematopoietic Stem Cell Transplantation: A Phase I Dose-Escalation Trial. Transplant Cell Ther 2021;27(11):932. PubMed
  6. Dou Y, Yu X, Luo Y, Chen B, Ma D, Zhu J. Effect of Fructooligosaccharides Supplementation on the Gut Microbiota in Human: A Systematic Review and Meta-Analysis. Nutrients 2022;14(16):3298. 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 Fructo-oligosaccharides (fos) and Isoniazid Together: Common Questions

Is it safe to take Fructo-oligosaccharides (fos) with Isoniazid?
We do not list a known interaction between Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos) 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 Fructo-oligosaccharides (fos) in each. That is a conversation for your prescriber, especially if Isoniazid is being adjusted to a target.
Does Isoniazid interact with any supplements?
Yes. Isoniazid has documented interactions with 84 supplements in our database — Fructo-oligosaccharides (fos) 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

Still Have a Question About Isoniazid and Fructo-oligosaccharides (fos)?

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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.