Drug & supplement interaction

Holy Basil + Metformin, Sitagliptin

Metformin, Sitagliptin brand names: Janumet, Janumet XR.

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

Holy Basil has a moderate interaction with Metformin, Sitagliptin. Theoretically, holy basil might increase the risk of hypoglycemia when taken with antidiabetes drugs.

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

Holy Basil 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 Holy Basil interacts with.

Theoretically, holy basil might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Small clinical studies show that taking holy basil can decrease fasting blood glucose and other measures of glycemic control in patients with type 2 diabetes.
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

Here's the simple version. Janumet combines two diabetes medicines (metformin and sitagliptin), and both work to bring your blood sugar down. Holy basil appears to have a mild blood sugar lowering effect of its own. So when you stack them together, the worry is that your numbers could drop a little lower than expected.

This isn't a dangerous chemical clash, and the evidence is fairly modest (a few small studies in people with type 2 diabetes). Still, if your sugar runs too low, you might feel shaky, sweaty, dizzy, hungry, or foggy. The most practical move is to check your glucose a bit more often when starting holy basil, and let your pharmacist or doctor know before you add it so they can keep an eye on your readings.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Agrawal P, Rai V, Singh RB. Randomized placebo-controlled, single blind trial of holy basil leaves in patients with noninsulin-dependent diabetes mellitus. Int J Clin Pharmacol Ther 1996;34:406-9.
  2. Somasundaram G, Manimekalai K, Salwe KJ, Pandiamunian J. Evaluation of the antidiabetic effect of Ocimum sanctum in type 2 diabetes patients. Int J Life Sci Pharma Res 2012;2(3):75-81.

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

Holy Basil Also Interacts With Other Medications

Holy Basil has 211 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 211 No known interaction 2,619 (incl. Metformin, Sitagliptin)
Taking anything else?

Check Another of Your Medications Against Holy Basil

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

From our Q&A

Questions About Holy Basil or Metformin, Sitagliptin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Holy Basil or Metformin, Sitagliptin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Metformin, Sitagliptin

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

We hold 1,867 real supplement products containing Holy Basil, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Holy Basil. Your product may carry other ingredients that interact with Metformin, Sitagliptin too, on top of Holy Basil — 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 Holy Basil 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 Holy Basil
Top 25%

#153 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 Holy Basil

What is Holy Basil?

Holy Basil
  • Stress and anxiety
  • Blood sugar support
  • Respiratory complaints
  • General immune and wellness support
  • Inflammation

Holy basil (tulsi) is a traditional Ayurvedic herb most often used today for stress and general wellness, but the human evidence is mostly small and preliminary. It is generally well tolerated by most adults, but it should be avoided in pregnancy and used cautiously by anyone with health conditions or taking medications. Talk to your pharmacist or doctor before starting it.

Read the full Holy Basil monograph & all interactions
Keep checking

Other Drugs & Holy Basil

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

0Major
211Moderate
0Minor
2,618No known interaction
211 Moderate 2,618 No interaction
Moderate

211 interactions

Showing 60 of 211 moderate interactions — see all 211 on the Holy Basil page.

No interaction 2,618 drugs checked — show the list

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

Showing the 60 most looked-up of 2,618 medications checked with no known interaction — see the full Holy Basil list.

See the full Holy Basil 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
Holy Basil 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 Holy Basil and Metformin, Sitagliptin Together: Common Questions

Can you take Holy Basil 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 Holy Basil 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 Holy Basil?

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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.