Drug & supplement interaction

Madagascar Periwinkle + Pioglitazone

Pioglitazone brand name: Actos.

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

Madagascar Periwinkle has a moderate interaction with Pioglitazone. Animal research shows that Madagascar periwinkle lowers blood glucose levels in diabetic rats.

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

Madagascar Periwinkle and Pioglitazone

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Pioglitazone

Pioglitazone falls under ANTIDIABETES DRUGS — the group Madagascar Periwinkle interacts with.

Animal research shows that Madagascar periwinkle lowers blood glucose levels in diabetic rats. Theoretically, using Madagascar periwinkle in combination with antidiabetes drugs might increase the risk of hypoglycemia; monitor blood glucose closely.
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 simple version: pioglitazone (Actos) already works to lower your blood sugar by making your body more sensitive to insulin. In animal studies, Madagascar periwinkle also nudged blood sugar down on its own. So the worry is that stacking the two together could push your sugar lower than intended.

I want to be honest about the strength of this concern. It comes from lab and animal research, not human studies, so it's more of a theoretical caution than a proven problem. Still, if your blood sugar drifts too low, you might feel shaky, sweaty, dizzy, or confused. Please don't start the herb on your own (and remember the raw plant is toxic), but if you're curious, check in with your pharmacist or doctor and keep an eye on your readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Oguntibeju OO, Aboua Y, Goboza M. Vindoline-A natural product from catharanthus roseus reduces hyperlipidemia and renal pathophysiology in experimental type 2 diabetes. Biomedicines. 2019 Aug 13;7(3):59. 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

Madagascar Periwinkle Also Interacts With Other Medications

Madagascar Periwinkle has 86 moderate known drug interactions in our database — the Pioglitazone one above is one of them. If you take anything else, check it against the full list below.

Moderate 86 No known interaction 2,744 (incl. Pioglitazone)
Taking anything else?

Check Another of Your Medications Against Madagascar Periwinkle

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

Everything else you take

See Every Supplement That Interacts With Pioglitazone

This page covers Madagascar Periwinkle only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pioglitazone page lists 356 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 309 moderate · 41 minor.

From our pharmacist’s overview on the Pioglitazone page

“Most of what appears on this pioglitazone (Actos) list shares one trait: the ingredients lower blood sugar on their own, which sounds helpful until you remember pioglitazone already does that job for people with type 2 diabetes. Stacked together, they can push glucose too low, and I would read this list with genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Pioglitazone interaction page

One more smart check

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

We hold 8 real supplement products containing Madagascar Periwinkle, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Madagascar Periwinkle. Your product may carry other ingredients that interact with Pioglitazone too, on top of Madagascar Periwinkle — 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 Madagascar Periwinkle and Pioglitazone 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 Madagascar Periwinkle
Top half

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

29 days ago today
Medication Pioglitazone
Steady interest

#2,298 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 Madagascar Periwinkle

What is Madagascar Periwinkle?

  • Diabetes (folk use)
  • High blood pressure (traditional use)
  • Sore throat and mouth ailments
  • Wound healing (topical)
  • Source of cancer chemotherapy drugs

Madagascar periwinkle is a flowering plant famous as the natural source of important chemotherapy drugs (vincristine and vinblastine), but the raw plant itself is toxic and not safe to use as a home remedy. While it has a long history in traditional medicine, there is no reliable evidence that taking the whole herb is safe or effective, and it should not be self-administered.

Read the full Madagascar Periwinkle monograph & all interactions
Medication

About Pioglitazone

What Is Pioglitazone Used For?

Brand name: Actos

Pioglitazone tablets — sold as Actos and under the generic names Pioglitazone and Pioglitazone Hydrochloride — are used to improve blood sugar (glucose) control in adults with type 2 diabetes. They are taken along with diet and exercise, either alone or combined with other diabetes medicines such as a sulfonylurea, metformin, or insulin.

Pioglitazone is not for type 1 diabetes or diabetic ketoacidosis (a serious complication where the blood becomes too acidic). It only works when the body is still producing some of its own insulin.

See full Pioglitazone drug information
Keep checking

Other Drugs & Madagascar Periwinkle

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Madagascar Periwinkle page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Madagascar Periwinkle list.

See the full Madagascar Periwinkle interactions page
See every supplement checked against Pioglitazone, 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
Madagascar Periwinkle monograph › Uses, safety, and every drug interaction in one place Pioglitazone supplement interactions › Every supplement checked against Pioglitazone, ranked by severity Pioglitazone drug information › The full plain-English guide to this medication 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 Madagascar Periwinkle and Pioglitazone Together: Common Questions

Can you take Madagascar Periwinkle with Pioglitazone?
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 Madagascar Periwinkle and Pioglitazone 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 Pioglitazone and Madagascar Periwinkle?

Our pharmacists answer your medication & supplement questions — free.

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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.