Drug & supplement interaction

Hibiscus Sabdariffa + Fosamprenavir

Fosamprenavir brand names: Lexiva, Telzir.

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

Hibiscus Sabdariffa has a minor interaction with Fosamprenavir. Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP3A4 substrates.

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

Hibiscus Sabdariffa and Fosamprenavir

Here is the interaction we found between these two, with the evidence behind it.

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Fosamprenavir

Fosamprenavir 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 Fosamprenavir (Lexiva). Fosamprenavir is actually a prodrug, meaning your body converts it into its active form, amprenavir, which is then handled by an enzyme called CYP3A4. In lab dishes, hibiscus extract has been shown to slow that same enzyme down. If that happened in real life, it could let a little more of the drug build up, which might mean more side effects like nausea, diarrhea, rash, or headache.

The important thing: this is purely theoretical and has never actually been seen in people. A cup or two of hibiscus tea is very unlikely to cause trouble. Concentrated supplements are the bigger question mark, so check with your pharmacist or doctor before using them regularly.

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 Fosamprenavir one above is one of 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. Fosamprenavir)
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 Fosamprenavir

This page covers Hibiscus Sabdariffa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fosamprenavir page lists 143 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 Adrafinil (moderate).

By severity: 3 major · 100 moderate · 40 minor.

From our pharmacist’s overview on the Fosamprenavir page

“Fosamprenavir (Lexiva, Telzir) keeps HIV suppressed only if its blood level stays where it belongs, so the 143 supplement interactions on file deserve real attention, not a shrug. Three are rated major and those are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Fosamprenavir interaction page

How much people look this up

Where Hibiscus Sabdariffa and Fosamprenavir 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

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

29 days ago today
Medication Fosamprenavir
Steady interest

#1,746 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 Fosamprenavir

What Is Fosamprenavir Used For?

Brand names: Lexiva, Telzir

Fosamprenavir tablets (sold as Fosamprenavir Calcium and Lexiva) are used together with other antiretroviral medicines to treat HIV-1 infection in adults and in children as young as 4 weeks old. It is not used alone — it is always part of a combination regimen.

For adults who have already taken protease inhibitor medicines before, fosamprenavir is used alongside a low dose of ritonavir. Once-daily dosing with ritonavir is not recommended for adults who have previously used protease inhibitors, or for any pediatric patients.

See full Fosamprenavir 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 Fosamprenavir, 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 Fosamprenavir supplement interactions › Every supplement checked against Fosamprenavir, ranked by severity Fosamprenavir 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 Fosamprenavir Together: Common Questions

Can you take Hibiscus Sabdariffa with Fosamprenavir?
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.
How serious is the Hibiscus Sabdariffa and Fosamprenavir 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 Fosamprenavir 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.