Drug & supplement interaction

Baikal Skullcap + Peginterferon alfa-2a

Peginterferon alfa-2a brand name: Pegasys IV.

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 Baikal Skullcap and Peginterferon alfa-2a 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

Baikal Skullcap and Peginterferon alfa-2a

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 Peginterferon alfa-2a and Baikal Skullcap 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.

Baikal Skullcap safety at a glance

Baikal Skullcap overall Use caution Often used in traditional medicine, but human safety data are limited and quality of products varies.
Pregnancy Avoid Not enough safety information; avoid use during pregnancy.
Breastfeeding Avoid Not enough safety information; avoid while breastfeeding.

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

Still wondering about combining Peginterferon alfa-2a and Baikal Skullcap? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
Keep it in perspective

Baikal Skullcap Does Interact With Other Medications

Baikal Skullcap has 594 moderate, 352 minor known drug interactions in our database — Peginterferon alfa-2a isn’t one of them. If you take anything else, check it against the full list below.

Moderate 594 Minor 352 No known interaction 1,884 (incl. Peginterferon alfa-2a)
Taking anything else?

Check Another of Your Medications Against Baikal Skullcap

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

What to actually watch for

No Interaction Found — But Data Suggests Baikal Skullcap and Peginterferon alfa-2a 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. One of them is worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    Baikal Skullcap

    “A specific combination product (Limbrel, Primus Pharmaceuticals) containing flavocoxid, a mixture of Baikal skullcap flavonoid extract and catechu extract, has been linked to several reports of acute liver damage. There have been at least five published reports of liver damage associated with this product. In all cases, the patients were females aged 54-68 years taking doses of 250-500 mg twice daily for 1-3 months.”

    Baikal Skullcap · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    6 sources cited
    1. 18009. Chalasani N, Vuppalanchi R, Navarro V, et al. Acute liver injury due to flavocoxid (Limbrel), a medical food for osteoarthritis: a case series. Ann Intern Med 2012;156:857-60. PubMed
    2. 96282. Papafragkakis C, Ona MA, Reddy M, Anand S. Acute hepatitis after ingestion of a preparation of Chinese skullcap and black catechu for joint pain. Case Reports Heptal 2016;2016:4356749. PubMed
    3. 18010. Reichenbach S, Juni P. Medical food and food supplements: not always as safe as generally assumed. Ann Intern Med 2012;156:894-5. PubMed
    4. 106042. US Food and Drug Administration (FDA). FDA Alerts Consumers About Potentially Life-Threatening Health Problems Linked to Limbrel. December 19, 2017. Available at: https://www.fda.gov/food/alerts-advisories-safety-information/fda-alerts-consumers-about-pot
    5. 33460. Linnebur, S. A., Rapacchietta, O. C., and Vejar, M. Hepatotoxicity associated with chinese skullcap contained in Move Free Advanced dietary supplement: two case reports and review of the literature. Pharmacotherapy 2010;30(7):750, 258e-750, 262e. PubMed
    6. 101737. Braude MR, Bassily R. Drug-induced liver injury secondary to Scutellaria baicalensis (Chinese skullcap). Intern Med J. 2019;49(4):544-546. PubMed

    Peginterferon alfa-2a

    Listed in the ADVERSE REACTIONS section of the FDA label for Peginterferon alfa-2a. Read the label on DailyMed ›

  • Fever Additional detail

    Baikal Skullcap

    “A specific combination product (Limbrel, Primus Pharmaceuticals) containing flavocoxid, a mixture of Baikal skullcap flavonoid extract and catechu extract, has been linked to several reports of hypersensitivity pneumonitis. Symptoms include fever, chills, headache, cough, chronic bronchitis, shortness of breath, weight loss, and fatigue.”

    Baikal Skullcap · Natural Medicines adverse-effect record, reported in acute bronchitis.

    1 source cited
    1. 106042. US Food and Drug Administration (FDA). FDA Alerts Consumers About Potentially Life-Threatening Health Problems Linked to Limbrel. December 19, 2017. Available at: https://www.fda.gov/food/alerts-advisories-safety-information/fda-alerts-consumers-about-pot

    Peginterferon alfa-2a

    Listed in the ADVERSE REACTIONS section of the FDA label for Peginterferon alfa-2a. Read the label on DailyMed ›

  • Itching Additional detail

    Baikal Skullcap

    “Orally, taking Baikal skullcap may cause erythema and pruritus. Intravenously, Baikal skullcap as part of a Tanreqing injection has been associated with reports of skin reactions in some pediatric patients.

    Topically, several cases of allergic contact dermatitis have been reported after applying sunscreen containing Baikal skullcap extract.”

    Baikal Skullcap · Natural Medicines adverse-effect record, reported in dermatitis.

    5 sources cited
    1. 105867. Li WJ, Bao J, Zheng DC, et al. Treatments of Peyronie's disease with Scutellaria baicalensis and surgery according to the disease course: a single-center retrospective study of 261 patients. Ann Palliat Med. 2021 Mar;10(3):2979-2989. PubMed
    2. 96281. Lin H, Zhou J, Lin K, et al. Efficacy of Scutellaria baicalensis for the treatment of hand, foot, and mouth disease associated with encephalitis in patients infected with EV71: a multicenter, retrospective analysis. Biomed Res Int 2016;2016:5697571.
    3. 105869. Adam T, Bursztejn AC, Schmutz JL. Facial eczema from a sunscreen: Scutellaria baicalensis, a novel allergen beginning to attract attention. Contact Dermatitis. 2020 Apr;82(4):253-254.
    4. 105870. Luna-Bastante L, Gatica-Ortega ME, Pastor-Nieto MA, et al. Allergic contact dermatitis to Tinosorb S, Scutellaria baicalensis, and other emerging allergens in cosmetics. Contact Dermatitis. 2020 May;82(5):307-309.
    5. 110024. Badaoui A. Allergic contact dermatitis to resveratrol and Scutellaria baicalensis root extract in a cosmetic product. Contact Dermatitis 2022.

    Peginterferon alfa-2a

    Listed in the ADVERSE REACTIONS section of the FDA label for Peginterferon alfa-2a. Read the label on DailyMed ›

  • Stomach pain / Diarrhea / Vomiting / Nausea Additional detail

    Baikal Skullcap

    “Orally, use of Baikal skullcap has been associated with epigastric pain, abdominal pain, constipation, diarrhea, nausea, and vomiting.”

    Baikal Skullcap · Natural Medicines adverse-effect record, reported in constipation.

    2 sources cited
    1. 101738. Shin NR, Gu N, Choi HS, Kim H. Combined effects of Scutellaria baicalensis with metformin on glucose tolerance of patients with type 2 diabetes via gut microbiota modulation. Am J Physiol Endocrinol Metab. 2020;318(1):E52-E61.
    2. 105867. Li WJ, Bao J, Zheng DC, et al. Treatments of Peyronie's disease with Scutellaria baicalensis and surgery according to the disease course: a single-center retrospective study of 261 patients. Ann Palliat Med. 2021 Mar;10(3):2979-2989. PubMed

    Peginterferon alfa-2a

    Listed in the ADVERSE REACTIONS section of the FDA label for Peginterferon alfa-2a. Read the label on DailyMed ›

  • Tiredness / Headache Additional detail

    Baikal Skullcap

    Recorded for Baikal Skullcap in the same Natural Medicines adverse-effect record shown under Fever above.

    Peginterferon alfa-2a

    Listed in the ADVERSE REACTIONS section of the FDA label for Peginterferon alfa-2a. Read the label on DailyMed ›

Reported for Baikal Skullcap but not commonly for Peginterferon alfa-2a: shortness of breath, an allergic reaction, constipation and weight loss.

Effects for Peginterferon alfa-2a come from the ADVERSE REACTIONS section of its FDA label; effects for Baikal Skullcap come from the Natural Medicines adverse-effect record, quoted above. 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 Peginterferon alfa-2a Is Prescribed For, and What Baikal Skullcap Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Peginterferon alfa-2a is a prescription medicine with approved uses on its FDA label. Baikal Skullcap is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Peginterferon alfa-2a is prescribed for: Pegasys (peginterferon alfa-2a) is used to treat chronic hepatitis C (CHC) and chronic hepatitis B (CHB). For chronic hepatitis C in adults, Pegasys is typically used in combination with other hepatitis C antiviral drugs; it may be used alone only if other HCV drugs cannot be tolerated or are contraindicated. For children aged 5 and older with CHC, Pegasys is used in combination with ribavirin. For chronic hepatitis B, Pegasys treats adults who have HBeAg-positive or HBeAg-negative CHB with compensated liver disease and evidence of active viral replication and liver inflammation.

Read the rest of what Peginterferon alfa-2a is prescribed for

In children aged 3 and older with HBeAg-positive CHB (without cirrhosis), Pegasys is also indicated when there is evidence of viral replication and liver enzyme elevation.

Baikal Skullcap has been studied for:

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

    Baikal Skullcap for hepatitis

    Although there has been interest in using oral Baikal skullcap for hepatitis, there is insufficient reliable information about the clinical effects of Baikal skullcap 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 Peginterferon alfa-2a on your own; if you are taking Baikal Skullcap for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

One more smart check

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

We hold 737 real supplement products containing Baikal Skullcap, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Baikal Skullcap. Even though Baikal Skullcap itself has no known interaction with Peginterferon alfa-2a, 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 Baikal Skullcap and Peginterferon alfa-2a 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 Baikal Skullcap
Top 25%

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

29 days ago today
Medication Peginterferon alfa-2a
Top 25%

#485 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 Baikal Skullcap reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Baikal Skullcap and Peginterferon alfa-2a 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 Baikal Skullcap

What is Baikal Skullcap?

Baikal Skullcap
  • Inflammation
  • Allergies
  • Anxiety and sleep
  • Immune support
  • Respiratory infections

Baikal skullcap is a traditional Chinese herb (Huang Qin) used for inflammation, allergies, and infections, with active compounds like baicalin and baicalein studied mostly in the lab. Human evidence remains limited, so it should not replace proven treatments. Talk to your pharmacist or doctor before using it, and avoid it in pregnancy and breastfeeding.

Scutellaria baicalensis · Lamiaceae · Root · Capsules, tablets, tinctures, dried root, teas, and standardized extracts

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

Baikal Skullcap: dosing

There is no well-established standard dose of Baikal skullcap. Products differ widely in their strength and in how much baicalin or baicalein they contain.The best approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Baikal Skullcap monograph & all interactions
Medication

About Peginterferon Alfa-2a Injection

What Is Peginterferon Alfa-2a Injection Used For?

Brand name: Pegasys IV

Pegasys (peginterferon alfa-2a) is used to treat chronic hepatitis C (CHC) and chronic hepatitis B (CHB). For chronic hepatitis C in adults, Pegasys is typically used in combination with other hepatitis C antiviral drugs; it may be used alone only if other HCV drugs cannot be tolerated or are contraindicated. For children aged 5 and older with CHC, Pegasys is used in combination with ribavirin.

For chronic hepatitis B, Pegasys treats adults who have HBeAg-positive or HBeAg-negative CHB with compensated liver disease and evidence of active viral replication and liver inflammation. In children aged 3 and older with HBeAg-positive CHB (without cirrhosis), Pegasys is also indicated when there is evidence of viral replication and liver enzyme elevation.

See full Peginterferon Alfa-2a Injection drug information
Keep checking

Other Drugs & Baikal Skullcap

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

0Major
594Moderate
352Minor
1,883No known interaction
594 Moderate 352 Minor 1,883 No interaction
Moderate

594 interactions

Showing 60 of 594 moderate interactions — see all 594 on the Baikal Skullcap page.

Minor

352 interactions

Showing 60 of 352 minor interactions — see all 352 on the Baikal Skullcap page.

No interaction 1,883 drugs checked — show the list

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

Showing the 60 most looked-up of 1,883 medications checked with no known interaction — see the full Baikal Skullcap list.

See the full Baikal Skullcap interactions page
See every supplement checked against Peginterferon alfa-2a, ranked by severity
Evidence & sources

Baikal Skullcap References

The 34 references that drive our Baikal Skullcap 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. Huang KC. The pharmacology of Chinese herbs. 2nd ed. New York, NY: CRC Press LLC. 1999;385-6, 400-1.
  2. Hui KM, Wang XH, Xue H. Interaction of flavones from the roots of Scutellaria baicalensis with the benzodiazepine site. Planta Med 2000;66:91-3.
  3. Liao JF, Wang HH, Chen MC, et al. Benzodiazepine binding site-interactive flavones from Scutellaria baicalensis root. Planta Med 1998;64:571-2.
  4. Nishioka T, Kawabata J, Aoyama Y. Baicalein, an alpha-glucosidase inhibitor from Scutellaria baicalensis. J Nat Prod 1998;61:1413-5.
  5. Zhang CZ, Wang SX, Zhang Y, et al. In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms. J Ethnopharmacol 2005;98:295-300. PubMed
  6. Fan L, Zhang W, Guo D, et al. The effect of herbal medicine baicalin on pharmacokinetics of rosuvastatin, substrate of organic anion-transporting polypeptide 1B1. Clin Pharmacol Ther 2007;83:471-6. PubMed
  7. Chen C, Mireles RJ, Campbell SD, et al. Differential interaction of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors with ABCB1, ABCC2, and OATP1B1. Drug Metab Dispos 2005;33:537-46. PubMed
  8. Pasanen MK, Fredrikson H, Neuvonen PJ, Niemi M. Different effects of SLCO1B1 polymorphism on the pharmacokinetics of atorvastatin and rosuvastatin. Clin Pharmacol Ther 2007;82:726-33. PubMed
  9. Konig J, Seithel A, Gradhand U, Fromm MF. Pharmacogenomics of human OATP transporters. Naunyn-Schmiedeberg Arch Pharmacol 2006;372:432-43. PubMed
  10. Chalasani N, Vuppalanchi R, Navarro V, et al. Acute liver injury due to flavocoxid (Limbrel), a medical food for osteoarthritis: a case series. Ann Intern Med 2012;156:857-60. PubMed
  11. Reichenbach S, Juni P. Medical food and food supplements: not always as safe as generally assumed. Ann Intern Med 2012;156:894-5. PubMed
  12. Huang, W. M., Yan, J., and Xu, J. [Clinical and experimental study on inhibitory effect of sanhuang mixture on platelet aggregation]. Zhongguo Zhong.Xi.Yi.Jie.He.Za Zhi. 1995;15(8):465-467.
  13. Kim, B. R., Kim, D. H., Park, R., Kwon, K. B., Ryu, D. G., Kim, Y. C., Kim, N. Y., Jeong, S., Kang, B. K., and Kim, K. S. Effect of an extract of the root of Scutellaria baicalensis and its flavonoids on aflatoxin B1 oxidizing cytochrome P450 enzymes. Pl PubMed
  14. Lee, Y., Yeo, H., Liu, S. H., Jiang, Z., Savizky, R. M., Austin, D. J., and Cheng, Y. C. Increased anti-P-glycoprotein activity of baicalein by alkylation on the A ring. J Med Chem 10-21-2004;47(22):5555-5566. PubMed
  15. Huang, Y., Tsang, S. Y., Yao, X., and Chen, Z. Y. Biological properties of baicalein in cardiovascular system. Curr Drug Targets.Cardiovasc.Haematol.Disord 2005;5(2):177-184. 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 Baikal Skullcap and Peginterferon alfa-2a Together: Common Questions

Is it safe to take Baikal Skullcap with Peginterferon alfa-2a?
We do not list a known interaction between Baikal Skullcap and Peginterferon alfa-2a. 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 Baikal Skullcap and Peginterferon alfa-2a have any of the same side effects?
Yes — our sources link each of them separately to 9 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 Baikal Skullcap and Peginterferon alfa-2a 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 Baikal Skullcap in each. That is a conversation for your prescriber, especially if Peginterferon alfa-2a is being adjusted to a target.
Does Baikal Skullcap interact with any other medications?
Yes. Baikal Skullcap has 946 documented drug interactions in our database — Peginterferon alfa-2a is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Baikal Skullcap monograph Uses, safety profile, and every drug interaction in one place Peginterferon Alfa-2a Injection drug information The full plain-English guide to this medication Peginterferon alfa-2a supplement interactions Every supplement checked against Peginterferon alfa-2a, 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 34 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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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.