Drug & supplement interaction

Genistein Combined Polysaccharide + Tapentadol

Tapentadol brand names: Nucynta, Nucynta ER.

Minor Interaction
Medically reviewed by · Updated June 2023
The bottom line Minor

Genistein Combined Polysaccharide has a minor interaction with Tapentadol. 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 Tapentadol

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

Minor

Cytochrome P450 2C9 (Cyp2C9) Substrates

Why this applies to Tapentadol

Tapentadol 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 honest version: the concern with GCP and CYP2C9 medications comes only from animal studies, and tapentadol (Nucynta) isn't a drug that leans heavily on that pathway anyway. Tapentadol is cleared mostly by a process called glucuronidation, with only minor involvement from liver enzymes like CYP2C9, and it works as-is rather than needing to be switched on, so it isn't a prodrug.

In theory, if genistein slowed that minor pathway slightly, you might see a touch more of tapentadol's usual effects, things like drowsiness, dizziness, nausea, or constipation. But honestly, the real-world risk here looks very small. Food amounts of soy are not a worry. If you're using a concentrated GCP supplement alongside an opioid, just give your pharmacist or doctor a heads-up so they can keep an eye on you.

Contact Dr. Brian directly if you have additional questions on this interaction

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 Tapentadol one above is one of them. If you take anything else, check it against the full list below.

Moderate 29 Minor 110 No known interaction 2,691 (incl. Tapentadol)
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 Tapentadol

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 Tapentadol, 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 Tapentadol

This page covers Genistein Combined Polysaccharide only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tapentadol page lists 113 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 Adrafinil (moderate).

By severity: 2 major · 84 moderate · 27 minor.

From our pharmacist’s overview on the Tapentadol page

“Tapentadol (Nucynta, Nucynta ER) is an opioid painkiller that also boosts serotonin signaling on its own, and that is exactly where its supplement list bites hardest. The two major-rated entries among the 113 on file deserve a hard look first: lithium, which alongside a serotonergic drug like tapentadol can raise the risk of serotonin…”

Reviewed by 2 · Jul 18, 2026

Open the Tapentadol interaction page

How much people look this up

Where Genistein Combined Polysaccharide and Tapentadol 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
Top half

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

29 days ago today
Medication Tapentadol
Steady interest

#2,080 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 Tapentadol

What Is Tapentadol Used For?

Brand names: Nucynta, Nucynta ER

Tapentadol tablets (including Nucynta and Tapentadol Hydrochloride tablets) are used for severe acute pain in adults when other treatments are not adequate. Nucynta tablets are also approved for acute pain in children aged 6 and older who weigh at least 40 kg.

Nucynta ER and tapentadol extended-release tablets are used for severe, ongoing pain that requires around-the-clock opioid treatment and cannot be managed with other options, including severe neuropathic pain (nerve pain) caused by diabetic peripheral neuropathy in adults. Extended-release formulations are not intended for as-needed use.

See full Tapentadol 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
29 Moderate 110 Minor 2,690 No 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

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

Showing the 60 most looked-up of 2,690 medications checked with no known interaction — see the full Genistein Combined Polysaccharide list.

See the full Genistein Combined Polysaccharide interactions page
See every supplement checked against Tapentadol, 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
Genistein Combined Polysaccharide monograph › Uses, safety, and every drug interaction in one place Tapentadol supplement interactions › Every supplement checked against Tapentadol, ranked by severity Tapentadol 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 Genistein Combined Polysaccharide and Tapentadol Together: Common Questions

Can you take Genistein Combined Polysaccharide with Tapentadol?
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 Tapentadol 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 Tapentadol 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.