Drug & supplement interaction

Hibiscus Sabdariffa + Thiotepa

Thiotepa brand names: Thioplex, Tepadina.

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

Thiotepa falls into 2 drug categories that Hibiscus Sabdariffa can interact with; the most serious is rated minor. Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP3A4 substrates.

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

Hibiscus Sabdariffa and Thiotepa

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

Why Are There 2 Interactions?

Hibiscus Sabdariffa interacts with whole categories of medication. Thiotepa falls into 2 of those categories, so it can interact with Hibiscus Sabdariffa in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Minor).

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 2

Why this applies to Thiotepa

Thiotepa falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Hibiscus Sabdariffa interacts with.

Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP3A4 substrates.
In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP3A4. This interaction has not been reported in humans.
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 with hibiscus and your thiotepa. The liver uses an enzyme called CYP3A4 to help process thiotepa, and lab (test tube) studies suggest hibiscus extract may slow that enzyme down a bit. In theory, that could let a little more active drug hang around, which might mean slightly stronger effects or side effects like low blood counts, nausea, or mouth sores. The honest part: this has only been seen in the lab, never confirmed in real people, so it's flagged as a minor, theoretical concern.

Thiotepa is serious chemotherapy that your oncology team monitors closely, so don't change anything on your own. An occasional cup of hibiscus tea is unlikely to matter much, but concentrated hibiscus supplements are worth running by your cancer doctor or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Johnson SS, Oyelola FT, Ari T, Juho H. In vitro inhibitory activities of the extract of Hibiscus sabdariffa L. (family Malvaceae) on selected cytochrome P450 isoforms. Afr J Tradit Complement Altern Med. 2013 Apr 12;10(3):533-40.
Minor

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES

2 of 2

Thiotepa also falls under CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES.

Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2B6 substrates.
In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2B6. This interaction has not been reported in humans.
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 thing about thiotepa: it's actually a prodrug. Your body relies on an enzyme called CYP2B6 to convert it into TEPA, the form that does most of the cancer-fighting work. Hibiscus is interesting here because, at least in lab dish studies, its extract appears to slow that same enzyme down. If it did the same thing in people, you might end up with less of the active form being made.

I want to be clear though, this is very much a theory on paper. It has never actually been seen in real patients, and it's rated as a minor concern. Still, thiotepa is serious chemotherapy, so I wouldn't add a concentrated hibiscus supplement without first checking with your oncology team. Occasional hibiscus tea is far less of a worry than capsules.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Johnson SS, Oyelola FT, Ari T, Juho H. In vitro inhibitory activities of the extract of Hibiscus sabdariffa L. (family Malvaceae) on selected cytochrome P450 isoforms. Afr J Tradit Complement Altern Med. 2013 Apr 12;10(3):533-40.

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

Hibiscus Sabdariffa Also Interacts With Other Medications

Hibiscus Sabdariffa has 2 major, 266 moderate, 818 minor known drug interactions in our database — the Thiotepa one above is among them. If you take anything else, check it against the full list below.

Major 2 Moderate 266 Minor 818 No known interaction 1,744 (incl. Thiotepa)
Taking anything else?

Check Another of Your Medications Against Hibiscus Sabdariffa

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

Everything else you take

See Every Supplement That Interacts With Thiotepa

This page covers Hibiscus Sabdariffa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Thiotepa page lists 146 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Acerola (moderate).

By severity: 3 major · 102 moderate · 41 minor.

From our pharmacist’s overview on the Thiotepa page

“Thiotepa (Thioplex, Tepadina) is chemotherapy, given for several cancers and to prepare patients for stem cell transplant, so its 146 supplement interactions make up a list to respect rather than skim. Three carry a major rating: grapefruit, St.”

Reviewed by 2 · Jul 18, 2026

Open the Thiotepa interaction page

How much people look this up

Where Hibiscus Sabdariffa and Thiotepa 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 Hibiscus Sabdariffa
Top half

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

29 days ago today
Medication Thiotepa
Steady interest

#2,095 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 Hibiscus Sabdariffa

What is Hibiscus Sabdariffa?

Hibiscus Sabdariffa
  • High blood pressure
  • Heart and cholesterol health
  • Digestive upset
  • Antioxidant support
  • Fever and general wellness

Hibiscus sabdariffa is a tart, cranberry-flavored plant most often consumed as a tea, and its best-studied use is for mildly lowering blood pressure. Evidence for other uses is limited, and while hibiscus tea is generally well tolerated in food amounts, concentrated supplements should be used cautiously and avoided in pregnancy. Talk to your pharmacist or doctor before using it for a medical condition.

Read the full Hibiscus Sabdariffa monograph & all interactions
Medication

About Thiotepa Injection

What Is Thiotepa Injection Used For?

Brand names: Thioplex, Tepadina

Tepadina (thiotepa) injection is used for several purposes. It treats adenocarcinoma (a type of cancer) of the breast or ovary. It is also used to control malignant effusions — abnormal fluid buildup in body cavities caused by cancer spreading to those areas. For bladder cancer, Tepadina treats superficial papillary carcinoma of the urinary bladder.

Tepadina is also used in pediatric patients with class 3 beta-thalassemia (a severe inherited blood disorder). In those patients, it is given as part of a preparative regimen — a conditioning treatment to reduce the risk of graft rejection before an allogeneic stem cell transplant (a transplant using donor stem cells), alongside the chemotherapy drugs busulfan and cyclophosphamide.

See full Thiotepa Injection drug information
Keep checking

Other Drugs & Hibiscus Sabdariffa

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

2Major
266Moderate
818Minor
1,743No known interaction
2 Major 266 Moderate 818 Minor 1,743 No interaction
Major

2 interactions

Moderate

266 interactions

Showing 60 of 266 moderate interactions — see all 266 on the Hibiscus Sabdariffa page.

Minor

818 interactions

Showing 60 of 818 minor interactions — see all 818 on the Hibiscus Sabdariffa page.

No interaction 1,743 drugs checked — show the list

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

Showing the 60 most looked-up of 1,743 medications checked with no known interaction — see the full Hibiscus Sabdariffa list.

See the full Hibiscus Sabdariffa interactions page
See every supplement checked against Thiotepa, 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
Hibiscus Sabdariffa monograph › Uses, safety, and every drug interaction in one place Thiotepa supplement interactions › Every supplement checked against Thiotepa, ranked by severity Thiotepa Injection drug information › The full plain-English guide to this medication 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 Hibiscus Sabdariffa and Thiotepa Together: Common Questions

Can you take Hibiscus Sabdariffa with Thiotepa?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Hibiscus Sabdariffa and Thiotepa?
Thiotepa belongs to more than one drug category, and Hibiscus Sabdariffa 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 Hibiscus Sabdariffa and Thiotepa interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Thiotepa and Hibiscus Sabdariffa?

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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.