Drug & supplement interaction

Holy Basil + Methylene Blue

Methylene Blue brand names: Urolene Blue, Provayblue.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Holy Basil and Methylene Blue in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Holy Basil and Methylene Blue

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Methylene Blue and Holy Basil in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Holy Basil safety at a glance

Holy Basil overall Use caution Generally well tolerated short-term in adults, but high-quality long-term safety data are limited.
Pregnancy Possibly Unsafe When used in high doses during pregnancy or when trying to conceive. Animal research suggests that relatively high doses of holy basil extract (200 mg/kg) may r... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used in high doses during pregnancy or when trying to conceive. Animal research suggests that relatively high doses of holy basil extract (200 mg/kg) may r... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Pharmacist analysis

While holy basil is generally considered a safe supplement with many different medications, and there is no known interaction in this case, it is important to be aware of some of its potential interactions.

Blood Thinning Drugs

  • Holy Basil may have mild blood-thinning properties.
  • Combining Holy Basil with medications like Warfarin, aspirin, or other anticoagulants/antiplatelet drugs could increase the risk of bleeding.

Blood Pressure Medications

  • Holy Basil may have mild hypotensive (blood pressure-lowering) effects.
  • Combining Holy Basil with medications used to treat high blood pressure, such as ACE inhibitors or beta-blockers, could potentially enhance the blood pressure-lowering effects.

Diabetes Medications

  • Holy Basil may have a hypoglycemic (blood sugar-lowering) effect.
  • Combining Holy Basil with diabetes medications like insulin or oral hypoglycemic drugs could potentially enhance the blood sugar-lowering effects.

Sedatives

  • Holy Basil has calming properties and may enhance the effects of sedatives or anxiety medications.
  • Combining Holy Basil with medications like benzodiazepines or sleep aids could potentially increase drowsiness or sedation.

Always talk to your healthcare provider or pharmacist before starting any new herbal supplement, including Holy Basil. They can provide personalized advice based on your specific medical history, medications, and overall health condition to ensure your safety and well-being.

—

Still wondering about combining Methylene Blue and Holy Basil? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Methylene Blue

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methylene Blue is filed under 3 classifications — serotonergic drugs, serotonergic drugs, oral drugs. Holy Basil has documented interactions with 3 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antidiabetes drugs (moderate) and pentobarbital (nembutal) (moderate) — and none of Methylene Blue’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Holy Basil Does Interact With Other Medications

Holy Basil has 212 moderate known drug interactions in our database — Methylene Blue isn’t one of them. If you take anything else, check it against the full list below.

Moderate 212 No known interaction 2,618 (incl. Methylene Blue)
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.

What to actually watch for

No Interaction Found — But Data Suggests Holy Basil and Methylene Blue May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Diarrhea / Nausea Additional detail

    Holy Basil

    “Orally, two out of 24 participants taking capsules containing holy basil extract in one clinical study experienced nausea or loose stools.

    Topically, holy basil mouthwash has been reported to cause a bitter taste in clinical trials.”

    Holy Basil · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    2 sources cited
    1. 55037. Mondal, S., Varma, S., Bamola, V. D., Naik, S. N., Mirdha, B. R., Padhi, M. M., Mehta, N., and Mahapatra, S. C. Double-blinded randomized controlled trial for immunomodulatory effects of Tulsi (Ocimum sanctum Linn.) leaf extract on healthy volunteers. J PubMed
    2. 55038. Agarwal, P. and Nagesh, L. Comparative evaluation of efficacy of 0.2% Chlorhexidine, Listerine and Tulsi extract mouth rinses on salivary Streptococcus mutans count of high school children--RCT. Contemp.Clin Trials 2011;32(6):802-808. PubMed

    Methylene Blue

    Listed in the ADVERSE REACTIONS section of the FDA label for Methylene Blue. Read the label on DailyMed ›

Reported for Holy Basil but not commonly for Methylene Blue: a change in taste.

Effects for Methylene Blue come from the ADVERSE REACTIONS section of its FDA label; effects for Holy Basil come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Holy Basil in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used in high doses during pregnancy or when trying to conceive. Animal research suggests that relatively high doses of holy basil extract (200 mg/kg) may reduce implantation rate when used for one week, while long-term use of higher doses (2-4 grams/kg) may decrease the number of full-term pregnancies. There is insufficient reliable information available regarding the safety of holy basil during lactation; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Holy Basil or Methylene Blue

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 Methylene Blue, 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 Methylene Blue

This page covers Holy Basil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methylene Blue page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 5-htp (moderate), Acetyl-l-carnitine (moderate) and Ayahuasca (moderate).

By severity: 2 major · 25 moderate · 11 minor.

From our pharmacist’s overview on the Methylene Blue page

“The pairing I would worry about first with methylene blue (Urolene Blue, Provayblue) is anything that raises serotonin, and lithium heads that group with a major rating. Methylene blue inhibits monoamine oxidase A, the enzyme that breaks serotonin down, so combining it with serotonin-boosting supplements can tip someone into serotonin…”

Reviewed by 2 · Jul 18, 2026

Open the Methylene Blue 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. Even though Holy Basil itself has no known interaction with Methylene Blue, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Holy Basil and Methylene Blue 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%

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

29 days ago today
Medication Methylene Blue
Top 5%

#53 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Holy Basil reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Holy Basil and Methylene Blue records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Ocimum tenuiflorum · Lamiaceae · Leaves, seeds, and essential oil · Tea, capsules, tablets, powder, liquid extract, essential oil

An interaction check asks whether these two react with each other — it does not ask whether Holy Basil is a good idea for someone in your situation. Here is what our Holy Basil record says about it on its own.

Holy Basil: dosing

There is no well-established standard dose of holy basil. Studies have used different forms and amounts, so it is hard to recommend a single reliable dose.If you choose to use it, follow the directions on the product label and do not exceed the recommended amount. They can help you decide whether it is appropriate and what amount may be reasonable.

From our Holy Basil monograph — the full record covers uses, side effects and every documented interaction.

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
212Moderate
0Minor
2,617No known interaction
212 Moderate 2,617 No interaction
Moderate

212 interactions

Showing 60 of 212 moderate interactions — see all 212 on the Holy Basil page.

No interaction 2,617 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 2,617 medications checked with no known interaction — see the full Holy Basil list.

See the full Holy Basil interactions page
See every supplement checked against Methylene Blue, ranked by severity
Evidence & sources

Holy Basil References

The 8 references that drive our Holy Basil monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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. Sakina MR, Dandiya PC, Hamdard ME, Hameed A. Preliminary psychopharmacological evaluation of Ocimum sanctum leaf extract. J Ethnopharmacol 1990;28:143-50. PubMed
  3. Singh S, Rehan HM, Majumdar DK. Effect of Ocimum sanctum fixed oil on blood pressure, blood clotting time and pentobarbitone-induced sleeping time. J Ethnopharmacol 2001;78:139-43. PubMed
  4. Mondal, S., Varma, S., Bamola, V. D., Naik, S. N., Mirdha, B. R., Padhi, M. M., Mehta, N., and Mahapatra, S. C. Double-blinded randomized controlled trial for immunomodulatory effects of Tulsi (Ocimum sanctum Linn.) leaf extract on healthy volunteers. J PubMed
  5. Agarwal, P. and Nagesh, L. Comparative evaluation of efficacy of 0.2% Chlorhexidine, Listerine and Tulsi extract mouth rinses on salivary Streptococcus mutans count of high school children--RCT. Contemp.Clin Trials 2011;32(6):802-808. PubMed
  6. Vohora, S. B., Garg, S. K., and Chaudhury, R. R. Antifertility screening of plants. 3. Effect of six indigenous plants on early pregnancy in albino rats. Indian J Med Res 1969;57(5):893-899.
  7. Khanna S, Gupta SR, Grover JK. Effect of long term feeding of tulsi (Ocimum sanctum Linn) on reproductive performance of adult albino rats. Indian J Exp Biol 1986;24(5):302-4.
  8. 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.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Holy Basil and Methylene Blue Together: Common Questions

Is it safe to take Holy Basil with Methylene Blue?
We do not list a known interaction between Holy Basil and Methylene Blue. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Holy Basil and Methylene Blue have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Holy Basil and Methylene Blue combination checked?
Interactions in our licensed database are recorded against drug classes. Methylene Blue is filed under 3 classifications, and Holy Basil has documented interactions with 3 drug classes — none of Methylene Blue's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Holy Basil interact with any other medications?
Yes. Holy Basil has 212 documented drug interactions in our database — Methylene Blue is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Methylene Blue interact with any supplements?
Yes. Methylene Blue has documented interactions with 38 supplements in our database — Holy Basil is not one of them. The Methylene Blue interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Holy Basil monograph Uses, safety profile, and every drug interaction in one place Methylene Blue supplement interactions Every supplement checked against Methylene Blue, 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 References The 8 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Methylene Blue 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.