Drug & supplement interaction

Astragalus + Oseltamivir Phosphate

Oseltamivir Phosphate brand name: Tamiflu.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Astragalus 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

Astragalus 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 Astragalus 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.

Astragalus safety at a glance

Astragalus overall Use caution Generally well tolerated short-term in healthy adults, but quality human safety data is limited.
Pregnancy Avoid Not enough reliable safety data, so it is best avoided during pregnancy.
Breastfeeding Avoid Not enough reliable safety data, so it is best avoided while breastfeeding.

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

Still wondering about combining Oseltamivir Phosphate and Astragalus? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Oseltamivir Phosphate

Interactions in our licensed database are recorded against drug classes, not just single drug names. Oseltamivir Phosphate is filed under 3 classifications — including organic anion transporter 1 (oat1) substrates, oral drugs. Astragalus has documented interactions with 4 drug classes — the most serious being antidiabetes drugs (moderate), cyclophosphamide (moderate) and immunosuppressants (moderate) — and none of Oseltamivir Phosphate’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

Astragalus Does Interact With Other Medications

Astragalus has 208 moderate known drug interactions in our database — Oseltamivir Phosphate isn’t one of them. If you take anything else, check it against the full list below.

Moderate 208 No known interaction 2,622 (incl. Oseltamivir Phosphate)
Taking anything else?

Check Another of Your Medications Against Astragalus

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

What to actually watch for

No Interaction Found — But Data Suggests Astragalus 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.

  • Nausea reported in 6.5% of FDA reports for Oseltamivir Phosphate Additional detail

    Astragalus

    “Orally, astragalus has reportedly been associated with enterocolitis and nausea in one clinical trial. However, these effects may not have been caused by astragalus.”

    Astragalus · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 17355. Matkovic Z, Zivkovic V, Korica M, et al. Efficacy and safety of Astragalus membranaceus in the treatment of patients with seasonal allergic rhinitis. Phytother Res 2010;24:175-81.

    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 Astragalus but not commonly for Oseltamivir Phosphate: muscle pain, heart failure, a fast or pounding heartbeat and sore throat.

Effects for Oseltamivir Phosphate come from the ADVERSE REACTIONS section of its FDA label; effects for Astragalus 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.

From our Q&A

Questions About Astragalus 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 Astragalus 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 Astragalus 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

One more smart check

Taking Astragalus as Part of a Dietary Supplement Product? Check It for Interactions

We hold 3,437 real supplement products containing Astragalus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Astragalus. Even though Astragalus itself has no known interaction with Oseltamivir Phosphate, 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 Astragalus 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 Astragalus
Top 5%

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

29 days ago today
Medication Oseltamivir Phosphate
Steady interest

#2,059 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 Astragalus reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Astragalus 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 Astragalus

What is Astragalus?

Astragalus
  • Immune support
  • Colds and flu
  • Upper respiratory infections
  • Fatigue and stress (adaptogen)
  • Heart health
  • General wellness in traditional medicine

Astragalus is a root used for centuries in traditional Chinese medicine, mainly to support the immune system and help the body cope with stress. While early studies are interesting, strong human evidence for most uses is still lacking. It is generally well tolerated by healthy adults for short-term use, but should be avoided during pregnancy and breastfeeding due to limited safety data.

Astragalus membranaceus · Fabaceae · Root · Capsules, tablets, dried root, tea, liquid extract (tincture), powder, and injectable forms used in some countries

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

Astragalus: dosing

There is no official, standardized dose of astragalus. The right amount can depend on the form (capsule, tea, extract), the part of the plant used, and how the product is prepared.Because doses vary widely between products and studies, the best advice is to follow the directions on the product label and not exceed them. A pharmacist can help you review a specific product and decide whether it is appropriate for you.If you start astragalus and notice any unwanted effects, stop and check with a healthcare professional. Avoid using it long-term without medical supervision, since long-term safety is not well established.

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

Read the full Astragalus 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 & Astragalus

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

0Major
208Moderate
0Minor
2,621No known interaction
208 Moderate 2,621 No interaction
Moderate

208 interactions

Showing 60 of 208 moderate interactions — see all 208 on the Astragalus page.

No interaction 2,621 drugs checked — show the list

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

Showing the 60 most looked-up of 2,621 medications checked with no known interaction — see the full Astragalus list.

See the full Astragalus interactions page
See every supplement checked against Oseltamivir Phosphate, ranked by severity
Evidence & sources

Astragalus References

The 13 references that drive our Astragalus 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. Upton R, ed. Astragalus Root: Analytical, quality control, and therapeutic monograph. Santa Cruz, CA: American Herbal Pharmacopoeia. 1999:1-25.
  2. Khoo KS, Ang PT. Extract of astragalus membranaceus and ligustrum lucidum does not prevent cyclophosphamide-induced myelosuppression. Singapore Med J 1995;36:387-90.
  3. Chu DT, Wong WL, Mavligit GM. Immunotherapy with Chinese medicinal herbs. II. Reversal of cyclophosphamide-induced immune suppression by administration of fractionated Astragalus membranaceus in vivo. J Clin Lab Immunol 1988;25:125-9.
  4. Sun Y, Hersh EM, Lee SL, et al. Preliminary observations on the effects of the Chinese medicinal herbs Astragalus membranaceus and Ligustrum lucidum on lymphocyte blastogenic responses. J Biol Response Mod 1983;2:227-37..
  5. Ma J, Peng A, Lin S. Mechanisms of the therapeutic effect of astragalus membranaceus on sodium and water retention in experimental heart failure. Chin Med J (Engl) 1998;111:17-23.
  6. Matkovic Z, Zivkovic V, Korica M, et al. Efficacy and safety of Astragalus membranaceus in the treatment of patients with seasonal allergic rhinitis. Phytother Res 2010;24:175-81.
  7. Zhang, J. G., Yang, N., He, H., Wei, G. H., Gao, D. S., Wang, X. L., Wang, X. Z., and Song, G. Y. [Effect of Astragalus injection on plasma levels of apoptosis-related factors in aged patients with chronic heart failure.]. Chin J Integr.Med 2005;11(3):18 PubMed
  8. Chen, H. W., Lin, I. H., Chen, Y. J., Chang, K. H., Wu, M. H., Su, W. H., Huang, G. C., and Lai, Y. L. A novel infusible botanically-derived drug, PG2, for cancer-related fatigue: a phase II double-blind, randomized placebo-controlled study. Clin Invest PubMed
  9. Tian H, Lu J, He H, et al.The effect of Astragalus as an adjuvant treatment in type 2 diabetes mellitus: A (preliminary) meta-analysis. J Ethnopharmacol. 2016;191:206-215. doi: 10.1016/j.jep.2016.05.062. PubMed
  10. Hong KF, Liu PY, Zhang W, Gui DK, Xu YH. The Efficacy and Safety of Astragalus as an Adjuvant Treatment for Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis. J Integr Complement Med 2023. PubMed
  11. Chan KW, Kwong ASK, Tsui PN, et al. Add-on astragalus in type 2 diabetes and chronic kidney disease: A multi-center, assessor-blind, randomized controlled trial. Phytomedicine 2024;130:155457. PubMed
  12. Han X, Yu T, Chen X, Du Z, Yu M, Xiong J. Effect of Astragalus membranaceus on left ventricular remodeling in HFrEF: a systematic review and meta-analysis. Front Pharmacol 2024;15:1345797. PubMed
  13. Jing P, Hongzheng H, Zhenqi WU, Meijuan Z, Zuojing LI, Gang C. Long-term efficacy and safety of Huangqi ()-based Traditional Chinese Medicine in diabetic peripheral neuropathy: a Meta-analysis of randomized controlled trials. J Tradit Chin Med 2024;44(2):

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 Astragalus and Oseltamivir Phosphate Together: Common Questions

Is it safe to take Astragalus with Oseltamivir Phosphate?
We do not list a known interaction between Astragalus 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 Astragalus 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.
How was the Astragalus and Oseltamivir Phosphate combination checked?
Interactions in our licensed database are recorded against drug classes. Oseltamivir Phosphate is filed under 3 classifications, and Astragalus has documented interactions with 4 drug classes — none of Oseltamivir Phosphate'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 Astragalus interact with any other medications?
Yes. Astragalus has 208 documented drug interactions in our database — Oseltamivir Phosphate 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 Oseltamivir Phosphate interact with any supplements?
Yes. Oseltamivir Phosphate has documented interactions with 22 supplements in our database — Astragalus 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

Where next

Keep Exploring

Astragalus monograph Uses, safety profile, and every drug interaction in one place Oseltamivir drug information The full plain-English guide to this medication Oseltamivir Phosphate supplement interactions Every supplement checked against Oseltamivir Phosphate, 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 13 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Oseltamivir Phosphate and Astragalus?

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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.