Drug & supplement interaction

Star Anise + 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 Star Anise 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

Star Anise 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 Star Anise 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Star Anise at all — not against Methylene Blue, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Star Anise safety at a glance

Star Anise overall Use caution The culinary spice is generally safe in food amounts, but concentrated supplements and look-alike toxic species raise concern.
Pregnancy Likely Safe When used orally in amounts commonly found in foods. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in amounts commonly found in foods. 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.

Still wondering about combining Methylene Blue and Star Anise? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Star Anise 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. One of them is worth acting on rather than waiting out — marked below.

  • Seizures Worth acting on Additional detail

    Star Anise

    “Orally, star anise is generally well tolerated when consumed in the amounts commonly found in food. However, star anise tea is associated with serious neurological adverse effects which may or may not be related to contamination with Japanese star anise (Illicium apisatum).

    Serious Adverse Effects (Rare):

    Orally: Tea made from star anise has been associated with increased deep tendon reflexes, irritability, jitterine…”

    Star Anise · Natural Medicines adverse-effect record, reported in epilepsy.

    “Orally, star anise tea has been reported to cause acute onset of irritability, jitteriness, hyperexcitability, clonus or myoclonus, increased deep tendon reflexes, rapid eye movements, nystagmus, and seizures. The teas consumed in these reports may or may not have been contaminated with Japanese star anise (Illicum apisatum).”

    Star Anise · Natural Medicines adverse-effect record, reported in epilepsy.

    5 sources cited
    1. 10407. Anon. FDA issue advisory on star anise "teas." FDA News P03-67; September 10, 2003.
    2. 11384. Ize-Ludlow D, Ragone S, Bernstein JN, et al. Chemical composition of Chinese star anise (Illicium verum) and neurotoxicity in infants. JAMA 2004;291:562-3. PubMed
    3. 13058. Ize-Ludlow D, Ragone S, Bruck IS, et al. Neurotoxicities in infants seen with the consumption of star anise tea. Pediatrics 2004;114:e653-6. PubMed
    4. 100159. Casanova Cuenca M, Calzado Agrasot MÁ, Mir Pegueroles C, Esteban Cantó V. New cases of star anise poisoning: Are we providing enough information? Neurologia. 2019;34(3):211-213. DOI
    5. 108932. Donner J, Ruest S. Neonate with seizures after consuming star anise tea. R I Med J. 2021 Oct 1;104(8):8-10.

    Methylene Blue

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

  • Diarrhea Additional detail

    Star Anise

    “Orally, star anise tea has been reported to cause vomiting, diarrhea, and abdominal distension. The teas consumed in these reports may or may not have been contaminated with Japanese star anise (Illicum apisatum).”

    Star Anise · Natural Medicines adverse-effect record, reported in diarrhea.

    4 sources cited
    1. 10407. Anon. FDA issue advisory on star anise "teas." FDA News P03-67; September 10, 2003.
    2. 13058. Ize-Ludlow D, Ragone S, Bruck IS, et al. Neurotoxicities in infants seen with the consumption of star anise tea. Pediatrics 2004;114:e653-6. PubMed
    3. 100159. Casanova Cuenca M, Calzado Agrasot MÁ, Mir Pegueroles C, Esteban Cantó V. New cases of star anise poisoning: Are we providing enough information? Neurologia. 2019;34(3):211-213. DOI
    4. 108932. Donner J, Ruest S. Neonate with seizures after consuming star anise tea. R I Med J. 2021 Oct 1;104(8):8-10.

    Methylene Blue

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

Reported for Star Anise but not commonly for Methylene Blue: bloating or gas, mood changes or irritability, anxiety or restlessness and a skin rash.

Effects for Methylene Blue come from the ADVERSE REACTIONS section of its FDA label; effects for Star Anise 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

Star Anise in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally in amounts commonly found in foods.

Pregnancy And Lactation Possibly Unsafe

When star anise is used orally as a tea. In 2003, the US Food and Drug Administration (FDA) issued an advisory to the public not to consume teas brewed from star anise, as they have been associated with adverse neurological and gastrointestinal effects.

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

Everything else you take

See Every Supplement That Interacts With Methylene Blue

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

We hold 126 real supplement products containing Star Anise, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Star Anise. Even though Star Anise 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 Star Anise 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 Star Anise
Top half

#627 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 Star Anise reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Star Anise 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 Star Anise

What is Star Anise?

  • Digestive upset and gas
  • Cough and respiratory complaints
  • Antimicrobial
  • Flavoring food and drinks
  • Source of shikimic acid for medicine manufacturing

Star anise (Illicium verum) is a star-shaped spice widely used in cooking and traditional medicine, mostly for digestive and respiratory complaints. Human evidence for health benefits is limited, and its main proven importance is as an industrial source of shikimic acid used to make antiviral medicine. Use the culinary Chinese star anise cautiously, avoid the toxic Japanese star anise look-alike, and check with your pharmacist before using supplements.

Illicium verum · Schisandraceae · Dried ripe fruit (the star-shaped seed pods) and essential oil · Whole or ground spice, tea, capsules, extracts, and essential oil

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

Star Anise: dosing

There is no well-established standard medicinal dose for star anise. It is most commonly used as a culinary spice or as a mild tea made from the whole star.If you use a supplement, capsule, or extract, follow the directions on the product label and do not exceed them.

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

Read the full Star Anise monograph & all interactions
Keep checking

Other Drugs & Star Anise

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Star Anise list.

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

Star Anise References

The 10 references that drive our Star Anise 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. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  2. Anon. FDA issue advisory on star anise "teas." FDA News P03-67; September 10, 2003.
  3. Ize-Ludlow D, Ragone S, Bernstein JN, et al. Chemical composition of Chinese star anise (Illicium verum) and neurotoxicity in infants. JAMA 2004;291:562-3. PubMed
  4. Ize-Ludlow D, Ragone S, Bruck IS, et al. Neurotoxicities in infants seen with the consumption of star anise tea. Pediatrics 2004;114:e653-6. PubMed
  5. Franks A. Contact allergy to anethole in toothpaste associated with loss of taste. Contact Dermatitis 1998;38:354-5. PubMed
  6. Rudzki E, Grzywa Z. Sensitizing and irritating properties of star anise oil. Contact Dermatitis 1976;2:305-8. PubMed
  7. Garzo, Fernandez C., Gomez, Pintado P., Barrasa, Blanco A., Martinez, Arrieta R., Ramirez, Fernandez R., and Ramon, Rosa F. [Cases of neurological symptoms associated with star anise consumption used as a carminative]. An.Esp.Pediatr. 2002;57(4):290-294.
  8. Minodier, P., Pommier, P., Moulene, E., Retornaz, K., Prost, N., and Deharo, L. [Star anise poisoning in infants]. Arch Pediatr. 2003;10(7):619-621.
  9. Casanova Cuenca M, Calzado Agrasot MÁ, Mir Pegueroles C, Esteban Cantó V. New cases of star anise poisoning: Are we providing enough information? Neurologia. 2019;34(3):211-213. DOI
  10. Donner J, Ruest S. Neonate with seizures after consuming star anise tea. R I Med J. 2021 Oct 1;104(8):8-10.

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 Star Anise and Methylene Blue Together: Common Questions

Is it safe to take Star Anise with Methylene Blue?
We do not list a known interaction between Star Anise 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 Star Anise 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.
Does Methylene Blue interact with any supplements?
Yes. Methylene Blue has documented interactions with 38 supplements in our database — Star Anise 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

Star Anise 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 10 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Methylene Blue and Star Anise?

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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.