Drug & supplement interaction

Bulbine Natalensis + Glipizide, Metformin

Glipizide, Metformin brand name: Metaglip.

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

Bulbine Natalensis has a moderate interaction with Glipizide, Metformin. Theoretically, Bulbine natalensis stem might reduce the levels and clinical effects of CYP2C9 substrates.

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

Bulbine Natalensis and Glipizide, Metformin

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

Why this applies to Glipizide, Metformin

Glipizide, Metformin falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Bulbine Natalensis interacts with.

Theoretically, Bulbine natalensis stem might reduce the levels and clinical effects of CYP2C9 substrates.
In vitro research shows that Bulbine natalensis stem extract induces CYP2C9 mRNA expression and enzyme activity. Theoretically, this may increase the metabolism of CYP2C9 substrates; however, this has not been studied in humans.
Severity Moderate Likelihood Possible Evidence D

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's the situation with Metaglip, which combines glipizide and metformin. The glipizide part is the piece that matters here, since it's cleared by a liver enzyme called CYP2C9. Lab studies hint that Bulbine natalensis may rev up that enzyme, which could mean your body breaks glipizide down a little faster than usual.

If that happened, glipizide might not work as well, and your blood sugar could creep higher than you'd like. I want to be honest though: this is only seen in test-tube research, not in real people, so it's more theoretical than proven. Given the liver and kidney safety concerns with this supplement too, please check with your pharmacist or doctor before pairing them, and keep an eye on your blood sugar readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Husain I, Dale OR, Manda V, et al. Bulbine natalensis (currently Bulbine latifolia) and select bulbine knipholones modulate the activity of AhR, CYP1A2, CYP2B6, and P-gp. Planta Med 2022;88(12):975-984. 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

Bulbine Natalensis Also Interacts With Other Medications

Bulbine Natalensis has 918 moderate known drug interactions in our database — the Glipizide, Metformin one above is one of them. If you take anything else, check it against the full list below.

Moderate 918 No known interaction 1,912 (incl. Glipizide, Metformin)
Taking anything else?

Check Another of Your Medications Against Bulbine Natalensis

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

Everything else you take

See Every Supplement That Interacts With Glipizide, Metformin

This page covers Bulbine Natalensis only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Glipizide, Metformin page lists 307 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Siberian Cocklebur (major), Acai (moderate), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 2 major · 257 moderate · 48 minor.

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

“Glipizide and metformin (Metaglip) already work hard to pull blood sugar down, which is exactly why this list of 307 ingredients deserves genuine vigilance rather than a shrug. Most of them, 239, can lower glucose on their own, and stacked on this pill the combined effect can tip into true hypoglycemia.”

Reviewed by 2 · Jul 18, 2026

Open the Glipizide, Metformin interaction page

One more smart check

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

We hold 51 real supplement products containing Bulbine Natalensis, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bulbine Natalensis. Your product may carry other ingredients that interact with Glipizide, Metformin too, on top of Bulbine Natalensis — 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 Bulbine Natalensis and Glipizide, 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 Bulbine Natalensis
Steady interest

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

29 days ago today
Medication Glipizide, Metformin
Top half

#891 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 Bulbine Natalensis

What is Bulbine Natalensis?

  • Boosting testosterone
  • Improving libido
  • Muscle building and athletic performance
  • General male vitality

Bulbine natalensis is a South African plant marketed mainly as a testosterone-boosting and libido supplement, but the human evidence is essentially absent and most claims come from animal studies. Animal research has also raised concerns about possible liver and kidney harm at higher doses, so caution is warranted. Talk to your pharmacist or doctor before trying it.

Read the full Bulbine Natalensis monograph & all interactions
Keep checking

Other Drugs & Bulbine Natalensis

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

0Major
918Moderate
0Minor
1,911No known interaction
918 Moderate 1,911 No interaction
Moderate

918 interactions

Showing 60 of 918 moderate interactions — see all 918 on the Bulbine Natalensis page.

No interaction 1,911 drugs checked — show the list

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

Showing the 60 most looked-up of 1,911 medications checked with no known interaction — see the full Bulbine Natalensis list.

See the full Bulbine Natalensis interactions page
See every supplement checked against Glipizide, 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
Bulbine Natalensis monograph › Uses, safety, and every drug interaction in one place Glipizide, Metformin supplement interactions › Every supplement checked against Glipizide, 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 Bulbine Natalensis and Glipizide, Metformin Together: Common Questions

Can you take Bulbine Natalensis with Glipizide, 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.
How serious is the Bulbine Natalensis and Glipizide, 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

Still Have a Question About Glipizide, Metformin and Bulbine Natalensis?

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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.