Drug & supplement interaction

Jambolan + Metformin, Sitagliptin

Metformin, Sitagliptin brand names: Janumet, Janumet XR.

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

Metformin, Sitagliptin falls into 2 drug categories that Jambolan can interact with; the most serious is rated moderate. Animal research shows that jambolan seed and bark extracts can lower blood glucose levels.

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

Jambolan and Metformin, Sitagliptin

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

Why Are There 2 Interactions?

Jambolan interacts with whole categories of medication. Metformin, Sitagliptin falls into 2 of those categories, so it can interact with Jambolan 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 Metformin, Sitagliptin

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

Animal research shows that jambolan seed and bark extracts can lower blood glucose levels. Theoretically, jambolan might have additive effects when used with antidiabetes drugs. This might increase the risk of hypoglycemia in some patients. Monitor blood glucose levels 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

Janumet combines two diabetes medicines, metformin and sitagliptin, that both work to bring your blood sugar down. Jambolan, especially in concentrated seed or bark supplements, may also nudge blood sugar lower. So the concern here isn't about how your body breaks the drug down. It's simply that two blood-sugar-lowering effects could stack on top of each other.

If they add up too much, you could drift into low blood sugar (hypoglycemia) with symptoms like shakiness, sweating, dizziness, or feeling foggy. Keep in mind this is based mostly on animal studies, so it's more theoretical than proven, and eating the fruit as food is unlikely to be a problem. Before starting a jambolan supplement, check in with your pharmacist or doctor and watch your numbers a little more closely at first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sharma SB, Nasir A, Prabhu KM, et al. Hypoglycaemic and hypolipidemic effect of ethanolic extract of seeds of Eugenia jambolana in alloxan-induced diabetic rabbits. J Ethnopharmacol 2003;85:201-6. PubMed
  2. Sridhar SB, Sheetal UD, Pai MR, Shastri MS. Preclinical evaluation of the antidiabetic effect of Eugenia jambolana seed powder in streptozotocin-diabetic rats. Braz J Med Biol Res 2005;38:463-8. PubMed
  3. Villasenor IM, Lamadrid MR. Comparative anti-hyperglycemic potentials of medicinal plants. J Ethnopharmacol 2006;104:129-31. PubMed
  4. Vora A, Varghese A, Kachwala Y, et al. Eugenia jambolana extract reduces the systemic exposure of Sitagliptin and improves conditions associated with diabetes: A pharmacokinetic and a pharmacodynamic herb-drug interaction study. J Tradit Complement Med. 2 PubMed
Minor

SITAGLIPTIN (Januvia)

2 of 2
Animal research shows that jambolan seed extract reduces the sitagliptin maximum plasma concentration and area under the curve by 39% and 22%, respectively. However, blood glucose levels were actually reduced to a greater extent in mice taking jambolan and sitagliptin in combination when compared with either product taken alone. Theoretically, jambolan seed extract might alter the clearance of sitagliptin, although this may not alter the clinical effects of sitagliptin.
Severity Minor 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 gist if you take Janumet (which combines metformin and sitagliptin) and you're curious about jambolan seed supplements. In animal studies, jambolan seed extract lowered blood levels of the sitagliptin part by roughly 20 to 40 percent. Normally, less drug in the blood would mean a weaker effect, but interestingly the mice taking both together still saw their blood sugar drop more, not less. So the picture is a bit muddy.

The big caveat: this is only lab and animal data, so we really don't know how it plays out in people. Eating the fruit as food is unlikely to matter. My honest advice is to loop in your pharmacist or doctor before adding a concentrated jambolan supplement, and keep an eye on your blood sugar readings if you do.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Vora A, Varghese A, Kachwala Y, et al. Eugenia jambolana extract reduces the systemic exposure of Sitagliptin and improves conditions associated with diabetes: A pharmacokinetic and a pharmacodynamic herb-drug interaction study. J Tradit Complement Med. 2 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

Jambolan Also Interacts With Other Medications

Jambolan has 185 moderate known drug interactions in our database — the Metformin, Sitagliptin one above is among them. If you take anything else, check it against the full list below.

Moderate 185 No known interaction 2,645 (incl. Metformin, Sitagliptin)
Taking anything else?

Check Another of Your Medications Against Jambolan

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

Everything else you take

See Every Supplement That Interacts With Metformin, Sitagliptin

This page covers Jambolan 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 Jambolan as Part of a Dietary Supplement Product? Check It for Interactions

We hold 91 real supplement products containing Jambolan, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Jambolan. Your product may carry other ingredients that interact with Metformin, Sitagliptin too, on top of Jambolan — 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 Jambolan 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 Jambolan
Top half

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

29 days ago today
Medication Metformin, Sitagliptin
Top half

#1,126 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 Jambolan

What is Jambolan?

  • Blood sugar support
  • Digestive upset and diarrhea
  • Sore throat and mouth health
  • Antimicrobial
  • General antioxidant support

Jambolan (Syzygium cumini), also called Java plum or black plum, is a tropical fruit tree traditionally used for blood sugar and digestive complaints. Human evidence for these uses is limited and not strong, so it should not replace proven treatments like diabetes medication. The fruit is safe as food, but talk to your pharmacist or doctor before using concentrated supplements.

Read the full Jambolan monograph & all interactions
Keep checking

Other Drugs & Jambolan

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

0Major
185Moderate
0Minor
2,644No known interaction
185 Moderate 2,644 No interaction
Moderate

185 interactions

Showing 60 of 185 moderate interactions — see all 185 on the Jambolan page.

No interaction 2,644 drugs checked — show the list

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

Showing the 60 most looked-up of 2,644 medications checked with no known interaction — see the full Jambolan list.

See the full Jambolan 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
Jambolan 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 Jambolan and Metformin, Sitagliptin Together: Common Questions

Can you take Jambolan 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.
Why are there 2 interactions listed for Jambolan and Metformin, Sitagliptin?
Metformin, Sitagliptin belongs to more than one drug category, and Jambolan 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 Jambolan 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

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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.