Drug & supplement interaction

Bupleurum + Losartan Potassium

Losartan Potassium brand name: Cozaar.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Bupleurum and Losartan Potassium 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

Bupleurum and Losartan Potassium

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 Losartan Potassium and Bupleurum 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.

Bupleurum safety at a glance

Bupleurum overall Use caution Generally used short-term in formulas, but it has been linked to rare lung and liver problems and quality varies.
Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Not enough safety information, 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 Losartan Potassium and Bupleurum? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Losartan Potassium

Interactions in our licensed database are recorded against drug classes, not just single drug names. Losartan Potassium is filed under 7 classifications — including angiotensin receptor blockers (arbs), cytochrome p450 2c9 (cyp2c9) substrates, antihypertensive drugs. Bupleurum has documented interactions with 3 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antidiabetes drugs (moderate) and immunosuppressants (moderate) — and none of Losartan Potassium’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

Bupleurum Does Interact With Other Medications

Bupleurum has 327 moderate known drug interactions in our database — Losartan Potassium isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Bupleurum

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

What to actually watch for

No Interaction Found — But Data Suggests Bupleurum and Losartan Potassium May Share Several of the Same Side Effects

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. 2 of them are worth acting on rather than waiting out — marked below.

  • Liver problems / A higher chance of infection Worth acting on Additional detail

    Bupleurum

    “Orally, combination products containing bupleurum have been reported to cause eosinophilic pneumonia, pulmonary edema, and multiple cases of pneumonitis. A specific combination product (sho-saiko-to), used in combination with interferon-alpha in patients with chronic active hepatitis, has also been associated with multiple cases of pneumonitis.”

    Bupleurum · Natural Medicines adverse-effect record, reported in hepatitis.

    6 sources cited
    1. 354. Kobashi Y, Nakajima M, Niki Y, Matsushima T. [A case of acute eosinophilic pneumonia due to Sho-saiko-to]. Nippon Kyobu Shikkan Gakkai Zasshi 1997;35:1372-7.
    2. 361. Miyazaki E, Ando M, Ih K, et al. [Pulmonary edema associated with the Chinese medicine shosaikoto]. Nihon Kokyuki Gakkai Zasshi 1998;36:776-80.
    3. 355. Wada Y, Kubo M. [Acute lymphoblastic leukemia complicated by type C hepatitis during treatment and further by acute interstitial pneumonia due to sho-saiko-to in 7-year-old]. Arerugi 1997;46:1148-55.
    4. 356. Sato A, Toyoshima M, Kondo A, et al. [Pneumonitis induced by the herbal medicine Sho-saiko-to in Japan]. Nippon Kyobu Shikkan Gakkai Zasshi 1997;35:391-5.
    5. 357. Daibo A, Yoshida Y, Kitazawa S, et al. [A case of pneumonitis and hepatic injury caused by a herbal drug (sho-saiko-to)]. Nippon Kyobu Shikkan Gakkai Zasshi 1992;30:1583-8.
    6. 37404. Sugiyama H, Nagai M, Kotajima F, and et al. [A case of interstitial pneumonia with chronic hepatitis C following interferon-alfa and sho-saiko-to therapy]. Arerugi 1995;44(7):711-714.

    Losartan Potassium

    Listed in the ADVERSE REACTIONS section of the FDA label for Losartan Potassium. Read the label on DailyMed ›

  • Numbness or tingling / Tiredness reported in 7.2% of FDA reports for Losartan Potassium Additional detail

    Bupleurum

    “Orally, a specific bupleurum-containing combination product (sho-saiko-to) has been reported to cause fatigue and paresthesia. It is unclear if these adverse effects are due to bupleurum, other ingredients, or the combination.”

    Bupleurum · Natural Medicines adverse-effect record, reported in fatigue.

    1 source cited
    1. 37391. Hirayama, C., Okumura, M., Tanikawa, K., and et al. A multicenter randomized controlled clinical trial of Shosaiko-to in chronic active hepatitis. Gastroenterol Jpn 1989;24(6):715-719. PubMed

    Losartan Potassium

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

  • Swelling Additional detail

    Bupleurum

    Recorded for Bupleurum in the same Natural Medicines adverse-effect record shown under Liver problems / A higher chance of infection above.

    Losartan Potassium

    Listed in the ADVERSE REACTIONS section of the FDA label for Losartan Potassium. Read the label on DailyMed ›

  • Nausea reported in 5.9% of FDA reports for Losartan Potassium Additional detail

    Bupleurum

    “Orally, a specific bupleurum-containing combination product (sho-saiko-to) has been reported to cause nausea, anorexia, and abdominal fullness. It is unclear if these adverse effects are due to bupleurum, other ingredients, or the combination.”

    Bupleurum · Natural Medicines adverse-effect record, reported in anorexia.

    1 source cited
    1. 37391. Hirayama, C., Okumura, M., Tanikawa, K., and et al. A multicenter randomized controlled clinical trial of Shosaiko-to in chronic active hepatitis. Gastroenterol Jpn 1989;24(6):715-719. PubMed

    Losartan Potassium

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

Reported for Bupleurum but not commonly for Losartan Potassium: reduced appetite.

Effects for Losartan Potassium come from the ADVERSE REACTIONS section of its FDA label; effects for Bupleurum come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 89,498 voluntary FDA FAERS reports for Losartan Potassium 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 Bupleurum or Losartan Potassium

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

This page covers Bupleurum only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Losartan Potassium page lists 253 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Grapefruit (major) and St. John's Wort (major).

By severity: 6 major · 205 moderate · 42 minor.

From our pharmacist’s overview on the Losartan Potassium page

“Losartan potassium (Cozaar) treats high blood pressure, and this is a list to respect, because six of its 253 supplement interactions carry a major rating. Most entries do one of two things.”

Reviewed by 2 · Jul 18, 2026

Open the Losartan Potassium interaction page

One more smart check

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

We hold 89 real supplement products containing Bupleurum, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bupleurum. Even though Bupleurum itself has no known interaction with Losartan Potassium, 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 Bupleurum and Losartan Potassium 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 Bupleurum
Top half

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

29 days ago today
Medication Losartan Potassium
Top 10

#6 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 Bupleurum reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Bupleurum and Losartan Potassium 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 Bupleurum

What is Bupleurum?

Bupleurum
  • Liver and digestive support
  • Cold, flu, and fever
  • Inflammation
  • Stress and mood
  • Immune support

Bupleurum (Chai Hu) is a root used in traditional Chinese medicine, usually as part of multi-herb formulas, for liver, digestive, and fever-related complaints. High-quality human evidence for its benefits is limited, and it has been linked to lung and liver problems in some reports, so use it cautiously and only under professional guidance.

Bupleurum chinense · Apiaceae · Root · Capsules, tablets, dried root, teas, tinctures, and traditional Chinese herbal formulas

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

Bupleurum: dosing

There is no well-established standard dose of Bupleurum. Do not exceed the recommended amount, and avoid long-term use without professional guidance.

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

Read the full Bupleurum monograph & all interactions
Medication

About Losartan

What Is Losartan Used For?

Brand name: Cozaar

Losartan tablets — available as branded Cozaar and several generic products — are used to treat high blood pressure (hypertension) in adults and children 6 years and older. Lowering blood pressure reduces the risk of strokes and heart attacks. Losartan tablets are also used to reduce the risk of stroke in people with high blood pressure who also have left ventricular hypertrophy (an enlarged left side of the heart). Note: evidence suggests this stroke-risk benefit may not apply to Black patients.

Losartan tablets are additionally approved to protect the kidneys in people with type 2 diabetes, high blood pressure, and signs of kidney damage (diabetic nephropathy). Arbli, the oral suspension form, shares these same approved uses.

Most-Reported Side Effects for Losartan Potassium

From FAERS, the FDA’s public side-effect reporting system (89,498 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 6,464 reports
Nausea 5,301 reports
Diarrhea 5,184 reports
Dyspnea 4,689 reports
Dizziness 4,429 reports
See full Losartan drug information
Keep checking

Other Drugs & Bupleurum

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

0Major
327Moderate
0Minor
2,502No known interaction
Moderate

327 interactions

Showing 60 of 327 moderate interactions — see all 327 on the Bupleurum page.

No interaction 2,502 drugs checked — show the list
Evidence & sources

Bupleurum References

The 17 references that drive our Bupleurum 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. Kobashi Y, Nakajima M, Niki Y, Matsushima T. [A case of acute eosinophilic pneumonia due to Sho-saiko-to]. Nippon Kyobu Shikkan Gakkai Zasshi 1997;35:1372-7.
  2. Wada Y, Kubo M. [Acute lymphoblastic leukemia complicated by type C hepatitis during treatment and further by acute interstitial pneumonia due to sho-saiko-to in 7-year-old]. Arerugi 1997;46:1148-55.
  3. Sato A, Toyoshima M, Kondo A, et al. [Pneumonitis induced by the herbal medicine Sho-saiko-to in Japan]. Nippon Kyobu Shikkan Gakkai Zasshi 1997;35:391-5.
  4. Daibo A, Yoshida Y, Kitazawa S, et al. [A case of pneumonitis and hepatic injury caused by a herbal drug (sho-saiko-to)]. Nippon Kyobu Shikkan Gakkai Zasshi 1992;30:1583-8.
  5. Sugiyama H, Nagai M, Kotajima F, et al. [A case of interstitial pneumonia with chronic hepatitis C following interferon-alfa and sho-saiko-to therapy]. Arerugi 1995;44:711-4.
  6. Ishizaki T, Sasaki F, Ameshima S, et al. Pneumonitis during interferon and/or herbal drug therapy in patients with chronic active hepatitis. Eur Respir J 1996;9:2691-6. PubMed
  7. Nakagawa A, Yamaguchi T, Takao T, Amano H. [Five cases of drug induced pneumonitis due to Sho-saiko-to or interferon-alpha or both]. Nippon Kyobu Shikkan Gakkai Zasshi 1995;33:1361-6.
  8. Miyazaki E, Ando M, Ih K, et al. [Pulmonary edema associated with the Chinese medicine shosaikoto]. Nihon Kokyuki Gakkai Zasshi 1998;36:776-80.
  9. Matsumoto T, Yamada H. Regulation of immune complexes binding of macrophages by pectic polysaccharide from Bupleurum falcatum L.: pharmacological evidence for the requirement of intracellular calcium/calmodulin on Fc receptor up-regulation by bupleuran 2
  10. Hattori T, Ito M, Suzuki Y. [Studies on antinephritic effects of plant components in rats (1). Effects of saikosaponins original-type anti-GBM nephritis in rats and its mechanisms]. Nippon Yakurigaku Zasshi 1991;97:13-21. PubMed
  11. Chang WC, Hsu FL. Inhibition of platelet activation and endothelial cell injury by flavan-3-ol and saikosaponin compounds. Prostaglandins Leukot Essent Fatty Acids 1991;44:51-6. PubMed
  12. Kato M, Pu MY, Isobe K, et al. Characterization of the immunoregulatory action of saikosaponin-d. Cell Immunol 1994;159:15-25. PubMed
  13. Ushio Y, Oda Y, Abe H. Effect of saikosaponin on the immune responses in mice. Int J Immunopharmacol 1991;13:501-8. PubMed
  14. Hirayama, C., Okumura, M., Tanikawa, K., and et al. A multicenter randomized controlled clinical trial of Shosaiko-to in chronic active hepatitis. Gastroenterol Jpn 1989;24(6):715-719. PubMed
  15. Hiai S, Yokoyama H, Nagasawa T, and et al. Stimulation of the pituitary-adrenocortical axis by saikosaponin of Bupleuri radix. Chemical and Pharmaceutical Bulletin (Tokyo) 1981;29(2):495-499. 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 Bupleurum and Losartan Potassium Together: Common Questions

Is it safe to take Bupleurum with Losartan Potassium?
We do not list a known interaction between Bupleurum and Losartan Potassium. 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 Bupleurum and Losartan Potassium have any of the same side effects?
Yes — our sources link each of them separately to 6 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 Bupleurum and Losartan Potassium combination checked?
Interactions in our licensed database are recorded against drug classes. Losartan Potassium is filed under 7 classifications, and Bupleurum has documented interactions with 3 drug classes — none of Losartan Potassium'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 Bupleurum interact with any other medications?
Yes. Bupleurum has 327 documented drug interactions in our database — Losartan Potassium 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 Losartan Potassium interact with any supplements?
Yes. Losartan Potassium has documented interactions with 253 supplements in our database — Bupleurum is not one of them. The Losartan Potassium 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 Losartan Potassium and Bupleurum?

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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.