Drug & supplement interaction

Genistein Combined Polysaccharide + Rabeprazole

Rabeprazole brand name: Pariet.

Minor Interaction
The bottom line Minor

Genistein Combined Polysaccharide has a minor interaction with Rabeprazole. Some evidence suggests that genistein can alter the pharmacokinetics of CYP2C9 substrates and should be used cautiously with them.

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

Genistein Combined Polysaccharide and Rabeprazole

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

Minor

Cytochrome P450 2C9 (Cyp2C9) Substrates

Why this applies to Rabeprazole

Rabeprazole falls under Cytochrome P450 2C9 (Cyp2C9) Substrates — the group Genistein Combined Polysaccharide interacts with.

Some evidence suggests that genistein can alter the pharmacokinetics of CYP2C9 substrates and should be used cautiously with them. This has only been seen in animal studies however. (PUBMED https://pubmed.ncbi.nlm.nih.gov/29387488/)
Severity Minor Likelihood Possible Evidence C

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 short version on combining GCP (which contains genistein) with your rabeprazole. The concern on file is that genistein might nudge an enzyme called CYP2C9, one of the liver enzymes that helps process certain medications. If that enzyme slows down, a drug it handles could linger a bit longer in your body.

The good news: this is theoretical and has only turned up in animal research, never confirmed in people. Rabeprazole is also a bit different from most acid reducers because it relies less on liver enzymes and more on a non-enzymatic pathway, so any real effect is likely small. Even if levels crept up, you'd mostly just see more of its usual effects (like headache or upset stomach). I wouldn't lose sleep over it, but since GCP is often used in hormone-sensitive situations, please loop in your oncologist or pharmacist before starting.

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

Genistein Combined Polysaccharide Also Interacts With Other Medications

Genistein Combined Polysaccharide has 29 moderate, 110 minor known drug interactions in our database — the Rabeprazole one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Genistein Combined Polysaccharide

Covers the 2,830 medications we’ve checked against Genistein Combined Polysaccharide. Pick one to open its full report.

From our Q&A

Questions About Genistein Combined Polysaccharide or Rabeprazole

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Genistein Combined Polysaccharide or Rabeprazole, 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 Rabeprazole

This page covers Genistein Combined Polysaccharide only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Rabeprazole page lists 172 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 · 119 moderate · 50 minor.

From our pharmacist’s overview on the Rabeprazole page

“Rabeprazole (Pariet) quiets stomach acid for reflux and ulcers, but its supplement list deserves genuine care, with three serious entries to understand before anything else. Most items matter because they change how the liver breaks rabeprazole down, so its level can drift up or down.”

Reviewed by 2 · Jul 18, 2026

Open the Rabeprazole interaction page

How much people look this up

Where Genistein Combined Polysaccharide and Rabeprazole 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 Genistein Combined Polysaccharide
Steady interest

#1,154 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Rabeprazole
Steady interest

#1,950 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 Genistein Combined Polysaccharide

What is Genistein Combined Polysaccharide?

  • Prostate cancer support
  • Bladder cancer support
  • Breast cancer support
  • Hormone-related cancers
  • Immune support

Genistein Combined Polysaccharide (GCP) is a soy-and-mushroom supplement studied mostly for hormone-related cancers like prostate cancer, but solid human evidence is still limited. It should never replace standard cancer treatment, and you should talk with your oncologist and pharmacist before using it, especially if you have a hormone-sensitive condition.

Read the full Genistein Combined Polysaccharide monograph & all interactions
Medication

About Rabeprazole

What Is Rabeprazole Used For?

Brand name: Pariet

Rabeprazole delayed-release tablets treat a range of acid-related conditions in adults, including healing and maintenance of erosive or ulcerative GERD (gastroesophageal reflux disease), symptomatic GERD, duodenal ulcers, and pathological hypersecretory conditions such as Zollinger-Ellison syndrome. They are also used alongside antibiotics (amoxicillin and clarithromycin) to eradicate H. pylori bacteria and reduce the risk of duodenal ulcer coming back.

In adolescents 12 years and older, rabeprazole delayed-release tablets are approved for short-term treatment of symptomatic GERD. Both AcipHex and Rabeprazole Sodium delayed-release tablets share this indication set for adults and adolescents 12 and older.

See full Rabeprazole drug information
Keep checking

Other Drugs & Genistein Combined Polysaccharide

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

0Major
29Moderate
110Minor
2,690No known interaction
Moderate

29 interactions

Minor

110 interactions

Showing 60 of 110 minor interactions — see all 110 on the Genistein Combined Polysaccharide page.

No interaction 2,690 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Genistein Combined Polysaccharide and Rabeprazole Together: Common Questions

Can you take Genistein Combined Polysaccharide with Rabeprazole?
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 Genistein Combined Polysaccharide and Rabeprazole 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 Rabeprazole and Genistein Combined Polysaccharide?

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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.