Drug & supplement interaction

Oscillococcinum + Oseltamivir Phosphate

Oseltamivir Phosphate brand name: Tamiflu.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Oscillococcinum and Oseltamivir Phosphate 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Oscillococcinum and Oseltamivir Phosphate

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 Oseltamivir Phosphate and Oscillococcinum 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 Oscillococcinum at all — not against Oseltamivir Phosphate, 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.

Oscillococcinum safety at a glance

Oscillococcinum overall Use caution Generally well tolerated, but evidence of benefit is lacking and it should not replace proven flu care.
Pregnancy Use caution Safety has not been well studied in pregnancy, so check with your doctor first.
Breastfeeding Use caution Little data exists during breastfeeding, so use only with medical guidance.

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

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

No Interaction Found — But Data Suggests Oscillococcinum and Oseltamivir Phosphate May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Headache reported in 3.9% of FDA reports for Oseltamivir Phosphate Additional detail

    Oscillococcinum

    “Orally, oscillococcinum has been associated with one report of headache in one clinical study.”

    Oscillococcinum · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 19063. Papp R, Schuback G, Beck E, et al. Oscillococcinum in patients with influenza-like syndromes: a placebo-controlled double-blind evaluation. British Homoeopathic Journal 1998;87:69-76.

    Oseltamivir Phosphate

    Listed in the ADVERSE REACTIONS section of the FDA label for Oseltamivir Phosphate, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Oscillococcinum but not commonly for Oseltamivir Phosphate: a severe allergic reaction.

Effects for Oseltamivir Phosphate come from the ADVERSE REACTIONS section of its FDA label; effects for Oscillococcinum come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 24,283 voluntary FDA FAERS reports for Oseltamivir Phosphate that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Oseltamivir Phosphate Is Prescribed For, and What Oscillococcinum Has Been Studied For

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

Oseltamivir Phosphate is prescribed for: Oseltamivir is used to treat acute, uncomplicated influenza A and B in patients 2 weeks of age and older who have had symptoms for no more than 48 hours. It is also used to prevent (prophylaxis) influenza A and B in patients 1 year of age and older. Keep in mind: oseltamivir is not a substitute for your annual flu vaccine. It does not work against bacterial infections or illnesses caused by anything other than influenza viruses.

Oscillococcinum has been studied for:

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

    Oscillococcinum for influenza

    While oral oscillococcinum does not appear to prevent influenza, small and potentially biased clinical studies suggest that it might reduce symptoms and the need for pain and fever medications in patients with influenza-like illness. It is unclear if these improvements are clinically meaningful.

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

From our Q&A

Questions About Oscillococcinum or Oseltamivir Phosphate

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

This page covers Oscillococcinum only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Oseltamivir Phosphate page lists 22 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), African Wild Potato (moderate), Banderol (moderate), Caffeic Acid (moderate) and Coffee Charcoal (moderate).

By severity: 1 major · 11 moderate · 10 minor.

From our pharmacist’s overview on the Oseltamivir Phosphate page

“Tamiflu (oseltamivir phosphate) only has about five days to do its job against the flu, so this list deserves a careful read, and the single major entry, activated charcoal, deserves it most. Charcoal can adsorb the drug and cut how much reaches your bloodstream, which is exactly what you cannot afford during a short antiviral course.”

Reviewed by 2 · Jul 18, 2026

Open the Oseltamivir Phosphate interaction page

How much people look this up

Where Oscillococcinum and Oseltamivir Phosphate 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 Oscillococcinum
Steady interest

#1,201 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Oseltamivir Phosphate
Steady interest

#1,924 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 Oscillococcinum reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Oscillococcinum and Oseltamivir Phosphate 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 Oscillococcinum

What is Oscillococcinum?

  • Flu-like symptoms
  • Common cold symptoms
  • Body aches and chills
  • Fatigue during illness
  • Fever associated with the flu

Oscillococcinum is a homeopathic product made from extremely diluted duck liver and heart, marketed to ease flu-like symptoms. High-quality research has not shown it works better than a placebo, but it is generally well tolerated. If you choose to try it, see it as a low-risk option rather than a proven treatment, and don't use it to replace a flu vaccine or needed medical care.

Anas barbariae hepatis et cordis extractum · Highly diluted extract of duck liver and heart (Muscovy duck) · Oral pellets/granules that dissolve under the tongue

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

Oscillococcinum: dosing

There is no scientifically established effective dose for Oscillococcinum, since it has not been shown to work. If you choose to use it, follow the directions on the product label exactly.The pellets are typically dissolved under the tongue rather than swallowed with water, and packages often suggest starting at the first sign of symptoms.

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

Read the full Oscillococcinum monograph & all interactions
Medication

About Oseltamivir

What Is Oseltamivir Used For?

Brand name: Tamiflu

Oseltamivir is used to treat acute, uncomplicated influenza A and B in patients 2 weeks of age and older who have had symptoms for no more than 48 hours. It is also used to prevent (prophylaxis) influenza A and B in patients 1 year of age and older.

Keep in mind: oseltamivir is not a substitute for your annual flu vaccine. It does not work against bacterial infections or illnesses caused by anything other than influenza viruses.

Most-Reported Side Effects for Oseltamivir Phosphate

From FAERS, the FDA’s public side-effect reporting system (24,283 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Vomiting 2,082 reports
Nausea 1,575 reports
Influenza 1,197 reports
Diarrhea 1,044 reports
Dyspnea 1,012 reports
See full Oseltamivir drug information
Keep checking

Other Drugs & Oscillococcinum

Browse every other medication we’ve checked against Oscillococcinum — 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

Oscillococcinum References

The 2 references that drive our Oscillococcinum 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. Papp R, Schuback G, Beck E, et al. Oscillococcinum in patients with influenza-like syndromes: a placebo-controlled double-blind evaluation. British Homoeopathic Journal 1998;87:69-76.
  2. Azmi Y, Rao M, Verma I, Agrawal A. Oscillococcinum leading to angioedema, a rare adverse event. BMJ Case Rep. 2015 Jun 2;2015. 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 Oscillococcinum and Oseltamivir Phosphate Together: Common Questions

Is it safe to take Oscillococcinum with Oseltamivir Phosphate?
We do not list a known interaction between Oscillococcinum and Oseltamivir Phosphate. 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.
Do Oscillococcinum and Oseltamivir Phosphate have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Oscillococcinum and Oseltamivir Phosphate 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 Oscillococcinum in each. That is a conversation for your prescriber, especially if Oseltamivir Phosphate is being adjusted to a target.
Does Oseltamivir Phosphate interact with any supplements?
Yes. Oseltamivir Phosphate has documented interactions with 22 supplements in our database — Oscillococcinum is not one of them. The Oseltamivir Phosphate 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 Oseltamivir Phosphate and Oscillococcinum?

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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.