Drug & supplement interaction

Baikal Skullcap + Glyburide, Metformin

Glyburide, Metformin brand name: Glucovance.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Glyburide, Metformin falls into 2 drug categories that Baikal Skullcap can interact with; the most serious is rated moderate. Theoretically, concomitant use of Baikal skullcap with antidiabetes drugs might enhance blood glucose lowering effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Baikal Skullcap and Glyburide, Metformin

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Baikal Skullcap interacts with whole categories of medication. Glyburide, Metformin falls into 2 of those categories, so it can interact with Baikal Skullcap in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIDIABETES DRUGS

1 of 2

Why this applies to Glyburide, Metformin

Glyburide, Metformin falls under ANTIDIABETES DRUGS — the group Baikal Skullcap interacts with.

Theoretically, concomitant use of Baikal skullcap with antidiabetes drugs might enhance blood glucose lowering effects.
Baicalein, a constituent of Baikal skullcap, has alpha-glucosidase inhibitory activity in vitro. Animal research also suggests that Baikal skullcap enhances the antidiabetic effects of metformin. However, in a small human study, taking Baikal skullcap extract did not enhance the antidiabetic effects of metformin, although it did modestly lower glucose levels during an oral glucose tolerance test (OGTT). Until more is known, use cautiously.
Severity Moderate Likelihood Possible Evidence B

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Glucovance combines two diabetes medicines: glyburide and metformin. Both work to lower your blood sugar. The thinking here is that Baikal skullcap may have a mild blood-sugar-lowering effect of its own, so pairing it with these medicines could push your glucose lower than expected. With glyburide especially, that can mean low blood sugar (hypoglycemia), which shows up as shakiness, sweating, dizziness, confusion, or a fast heartbeat.

Honestly, the evidence is on the weaker side. Lab and animal studies hint at this, but a small human study didn't show skullcap boosting metformin's effect, just a modest dip in glucose during a sugar test. So it's a maybe, not a sure thing. If you'd like to try it, check with your pharmacist or doctor first and keep an eye on your sugar readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Nishioka T, Kawabata J, Aoyama Y. Baicalein, an alpha-glucosidase inhibitor from Scutellaria baicalensis. J Nat Prod 1998;61:1413-5.
  2. Waisundara, V. Y., Hsu, A., Huang, D., and Tan, B. K. Scutellaria baicalensis enhances the anti-diabetic activity of metformin in streptozotocin-induced diabetic Wistar rats. Am J Chin Med 2008;36(3):517-540.
  3. 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.
Minor

ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP)

2 of 2

Glyburide, Metformin also falls under ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP).

Theoretically, Baikal skullcap might alter the levels and clinical effects of OATP substrates.
Some pharmacokinetic research shows that baicalin, a constituent of Baikal skullcap, can decrease plasma levels of rosuvastatin. The mechanism is thought to involve stimulation of the activity of the organic anion-transporting polypeptide 1B1 (OATP1B1), which transports rosuvastatin into the liver. This decreases plasma levels of the drug, but increases levels at the site of action in the liver. The degree to which rosuvastatin levels are affected depends on the OATP1B1 haplotype of the individual. Baikal skullcap might also affect other OATP1B1 substrates.
Severity Minor Likelihood Possible Evidence B

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here is the gist for your Glucovance, which combines glyburide and metformin. Baikal skullcap may nudge a liver transporter called OATP1B1 to work a little faster. The same compound (baicalin) was shown in research to slightly lower blood levels of rosuvastatin by moving it into the liver quicker. This is mostly theoretical for glyburide and metformin, the evidence is weak, and it is rated a minor interaction.

If it had any effect at all, it might modestly lower how much glyburide is circulating, which could make your blood sugar control a touch less reliable. In real life that is unlikely to be a big deal, but since blood sugar matters, I would mention this herb to your pharmacist or doctor and keep an eye on your glucose readings rather than stopping anything.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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
  2. 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
  3. 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
  4. Konig J, Seithel A, Gradhand U, Fromm MF. Pharmacogenomics of human OATP transporters. Naunyn-Schmiedeberg Arch Pharmacol 2006;372:432-43. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Baikal Skullcap Also Interacts With Other Medications

Baikal Skullcap has 593 moderate, 352 minor known drug interactions in our database — the Glyburide, Metformin one above is among them. If you take anything else, check it against the full list below.

Moderate 593 Minor 352 No known interaction 1,885 (incl. Glyburide, Metformin)
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.

Everything else you take

See Every Supplement That Interacts With Glyburide, Metformin

This page covers Baikal Skullcap only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Glyburide, Metformin page lists 332 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Beer (major), Grapefruit (major) and Siberian Cocklebur (major).

By severity: 7 major · 281 moderate · 44 minor.

From our pharmacist’s overview on the Glyburide, Metformin page

“Glucovance combines glyburide and metformin to lower blood sugar, and its list of 332 interacting supplements deserves real care, starting with the seven rated major. Most entries, 239 of them, lower blood sugar on their own, so stacking one on top of a drug built to do exactly that can drop your glucose into dangerous territory.”

Reviewed by 2 · Jul 18, 2026

Open the Glyburide, Metformin interaction page

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. Your product may carry other ingredients that interact with Glyburide, Metformin too, on top of Baikal Skullcap — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Baikal Skullcap and Glyburide, Metformin 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%

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

29 days ago today
Medication Glyburide, Metformin
Steady interest

#1,602 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.

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.

Read the full Baikal Skullcap monograph & all interactions
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
593Moderate
352Minor
1,884No known interaction
593 Moderate 352 Minor 1,884 No interaction
Moderate

593 interactions

Showing 60 of 593 moderate interactions — see all 593 on the Baikal Skullcap page.

Minor

352 interactions

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

No interaction 1,884 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 1,884 medications checked with no known interaction — see the full Baikal Skullcap list.

See the full Baikal Skullcap interactions page
See every supplement checked against Glyburide, Metformin, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Baikal Skullcap monograph › Uses, safety, and every drug interaction in one place Glyburide, Metformin supplement interactions › Every supplement checked against Glyburide, Metformin, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Baikal Skullcap and Glyburide, Metformin Together: Common Questions

Can you take Baikal Skullcap with Glyburide, Metformin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Baikal Skullcap and Glyburide, Metformin?
Glyburide, Metformin belongs to more than one drug category, and Baikal Skullcap interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Baikal Skullcap and Glyburide, Metformin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

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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.