Drug & supplement interaction

Madagascar Periwinkle + Liraglutide

Liraglutide brand name: Victoza.

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

Madagascar Periwinkle has a moderate interaction with Liraglutide. 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 Liraglutide

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Liraglutide

Liraglutide 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: Liraglutide (Victoza) already works to bring your blood sugar down. In animal studies, Madagascar periwinkle also lowered blood sugar in diabetic rats. So the worry is that stacking the two could push your numbers too low, raising the risk of hypoglycemia. That can feel like shakiness, sweating, dizziness, a racing heart, confusion, or in serious cases passing out.

I want to be honest about the strength of this, though. It's based only on lab and animal research, not human studies, so it stays theoretical for now. On top of that, the raw periwinkle plant is genuinely toxic and shouldn't be used as a home remedy at all. If you're considering it, please loop in your doctor or pharmacist first and keep an eye on your blood sugar.

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 Liraglutide 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. Liraglutide)
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 Liraglutide

This page covers Madagascar Periwinkle only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Liraglutide page lists 239 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Siberian Cocklebur (major), Acai (moderate), African Wild Potato (moderate), Agaricus Mushroom (moderate) and Agmatine (moderate).

By severity: 1 major · 208 moderate · 30 minor.

From our pharmacist’s overview on the Liraglutide page

“If you take liraglutide (Victoza), the ingredient to know first is Siberian cocklebur, the only major-rated interaction of the 239 on this page. Its seeds have caused severe hypoglycemia in people, dangerously low blood sugar, and liraglutide already pushes glucose down.”

Reviewed by 2 · Jul 18, 2026

Open the Liraglutide 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 Liraglutide 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 Liraglutide 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

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

29 days ago today
Medication Liraglutide
Steady interest

#1,885 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 Liraglutide Injection

What Is Liraglutide Injection Used For?

Brand name: Victoza

Saxenda is used alongside a reduced-calorie diet and increased physical activity for chronic weight management. It is approved for adults with a BMI of 30 or higher, or a BMI of 27 or higher if they also have at least one weight-related condition such as high blood pressure, type 2 diabetes, or dyslipidemia (abnormal cholesterol or fat levels). It is also approved for adolescents aged 12 and older who weigh more than 60 kg and meet certain BMI thresholds for obesity.

Saxenda should not be used together with other liraglutide-containing products or any other GLP-1 receptor agonist. Its safety and effectiveness in combination with other prescription or over-the-counter weight-loss products have not been established.

See full Liraglutide Injection 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 Liraglutide, 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 Liraglutide supplement interactions › Every supplement checked against Liraglutide, ranked by severity Liraglutide Injection 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 Liraglutide Together: Common Questions

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

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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.