Drug & supplement interaction

Maritime Pine + Metformin, Sitagliptin

Metformin, Sitagliptin brand names: Janumet, Janumet XR.

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

Maritime Pine has a moderate interaction with Metformin, Sitagliptin. Theoretically, maritime pine bark extract might increase the risk of hypoglycemia when used with antidiabetes drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceB
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Maritime Pine and Metformin, Sitagliptin

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

Moderate

ANTIDIABETES DRUGS

Why this applies to Metformin, Sitagliptin

Metformin, Sitagliptin falls under ANTIDIABETES DRUGS — the group Maritime Pine interacts with.

Theoretically, maritime pine bark extract might increase the risk of hypoglycemia when used with antidiabetes drugs.
One clinical study shows that maritime pine bark extract decreases blood sugar in patients with diabetes being treated with antidiabetes agents. Monitor blood glucose levels closely. Dose adjustments might be necessary.
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

Janumet combines two diabetes medicines, metformin and sitagliptin, that already work to bring your blood sugar down. Maritime pine bark (Pycnogenol) may have a mild blood-sugar-lowering effect of its own. So the worry here isn't that one blocks the other, it's that the two together could push your numbers lower than intended.

If your sugar drops too far, you might feel shaky, sweaty, dizzy, irritable, or get a headache. The good news: this is rated moderate and rests on limited evidence, so for many people it's manageable. If you'd like to try the supplement, check your glucose more often at first and let your pharmacist or doctor know, since your Janumet dose may need a small tweak. Please don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu X, Wei J, Tan F, et al. Antidiabetic effect of Pycnogenol French maritime pine bark extract in patients with diabetes type II. Life Sci 2004;75:2505-13. 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

Maritime Pine Also Interacts With Other Medications

Maritime Pine has 326 moderate known drug interactions in our database — the Metformin, Sitagliptin one above is one of them. If you take anything else, check it against the full list below.

Moderate 326 No known interaction 2,504 (incl. Metformin, Sitagliptin)
Taking anything else?

Check Another of Your Medications Against Maritime Pine

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

Everything else you take

See Every Supplement That Interacts With Metformin, Sitagliptin

This page covers Maritime Pine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metformin, Sitagliptin page lists 257 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), African Wild Potato (moderate) and Agaricus Mushroom (moderate).

By severity: 2 major · 217 moderate · 38 minor.

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

“Many people prescribed metformin with sitagliptin (Janumet, Janumet XR) for type 2 diabetes also try herbs sold as blood sugar support, fenugreek among the most popular, and that habit is exactly where the risk on this page concentrates. Of 257 documented supplement interactions, 239 can push glucose in the same direction the medicatio…”

Reviewed by 2 · Jul 18, 2026

Open the Metformin, Sitagliptin interaction page

One more smart check

Taking Maritime Pine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 452 real supplement products containing Maritime Pine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Maritime Pine. Your product may carry other ingredients that interact with Metformin, Sitagliptin too, on top of Maritime Pine — 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 Maritime Pine and Metformin, Sitagliptin 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 Maritime Pine
Top 25%

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

29 days ago today
Medication Metformin, Sitagliptin
Top half

#887 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 Maritime Pine

What is Maritime Pine?

Maritime Pine
  • Circulation and vein health
  • Antioxidant support
  • Skin health and aging
  • High blood pressure
  • Joint comfort

Maritime pine bark extract (often sold as Pycnogenol) is a plant-based antioxidant most studied for circulation, vein, and skin health. Some research is promising, but many studies are small or industry-funded, so benefits are not firmly proven. It is generally well tolerated, but talk to your pharmacist or doctor before starting it.

Read the full Maritime Pine monograph & all interactions
Keep checking

Other Drugs & Maritime Pine

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

0Major
326Moderate
0Minor
2,503No known interaction
326 Moderate 2,503 No interaction
Moderate

326 interactions

Showing 60 of 326 moderate interactions — see all 326 on the Maritime Pine page.

No interaction 2,503 drugs checked — show the list

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

Showing the 60 most looked-up of 2,503 medications checked with no known interaction — see the full Maritime Pine list.

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

Can you take Maritime Pine with Metformin, Sitagliptin?
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 Maritime Pine and Metformin, Sitagliptin 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 Metformin, Sitagliptin and Maritime Pine?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.