Drug & supplement interaction

Genistein Combined Polysaccharide + Methadone

Methadone brand name: Dolophine.

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 Genistein Combined Polysaccharide and Methadone 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

Genistein Combined Polysaccharide and Methadone

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 Methadone and Genistein Combined Polysaccharide 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.

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.

Genistein Combined Polysaccharide safety at a glance

Genistein Combined... overall Use caution Human safety data is limited, so use only with medical guidance.
Pregnancy Avoid Because it acts like estrogen and lacks safety data, avoid during pregnancy.
Breastfeeding Avoid Not enough safety information, so it is best avoided while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Methadone and Genistein Combined Polysaccharide? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Methadone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Methadone is filed under 11 classifications — including narcotic drugs, cytochrome p450 2d6 (cyp2d6) inhibitors, serotonergic drugs. Genistein Combined Polysaccharide has documented interactions with 2 drug classes — the most serious being caffeine (moderate) and cytochrome p450 2c9 (cyp2c9) substrates (minor) — and none of Methadone’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Genistein Combined Polysaccharide Does Interact With Other Medications

Genistein Combined Polysaccharide has 29 moderate, 111 minor known drug interactions in our database — Methadone isn’t one of them. If you take anything else, check it against the full list below.

Moderate 29 Minor 111 No known interaction 2,690 (incl. Methadone)
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.

What to actually watch for

No Interaction Found — But Data Suggests Genistein Combined Polysaccharide and Methadone May Share a Side Effect

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.

  • Nausea Additional detail

    Genistein Combined Polysaccharide

    “In one case report, a patient with bladder cancer taking genistein combined polysaccharide 5 grams daily experienced mild nausea and diarrhea.”

    Genistein Combined Polysaccharide · Natural Medicines adverse-effect record, reported in bladder cancer.

    1 source cited
    1. 95165. Capodice JL, Cammack AS, McKiernan JM, Katz AE. Two case reports on the use of genistein combined polysaccharide (GCP) against bladder cancer recurrence. J Complement Integr Med 2011;8. PubMed

    Methadone

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

Reported for Genistein Combined Polysaccharide but not commonly for Methadone: diarrhea.

Effects for Methadone come from the ADVERSE REACTIONS section of its FDA label; effects for Genistein Combined Polysaccharide 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.

From our Q&A

Questions About Genistein Combined Polysaccharide or Methadone

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 Methadone, 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 Methadone

This page covers Genistein Combined Polysaccharide only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methadone page lists 223 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Grapefruit (major).

By severity: 10 major · 174 moderate · 39 minor.

From our pharmacist’s overview on the Methadone page

“If you take methadone, choose your supplements with genuine care. Of the 223 ingredients on this page, most either add to methadone's sedating effect or change how fast your body clears it, which can push its blood level up or down.”

Reviewed by 2 · Jul 18, 2026

Open the Methadone interaction page

How much people look this up

Where Genistein Combined Polysaccharide and Methadone 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 Methadone
Top 25%

#584 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 Genistein Combined Polysaccharide reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Genistein Combined Polysaccharide and Methadone 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 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.

Soybean-derived genistein combined with polysaccharides from basidiomycete mushrooms · Capsules, tablets

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

Genistein Combined Polysaccharide: dosing

There is no officially established or standardized dose for Genistein Combined Polysaccharide. Different products contain different amounts and formulations, so the right amount is not clear.If you choose to use GCP, follow the directions on the specific product label and do not exceed them.

From our Genistein Combined Polysaccharide monograph — the full record covers uses, side effects and every documented interaction.

Read the full Genistein Combined Polysaccharide monograph & all interactions
Medication

About Methadone

What Is Methadone Used For?

Brand name: Dolophine

Methadone treats severe and persistent pain that requires daily, around-the-clock, long-term opioid treatment and cannot be managed adequately with other options. It is available in several forms for this use, including oral solution, oral tablets, oral concentrate, and injectable forms (intravenous, intramuscular, and subcutaneous). Injectable methadone is not approved for outpatient pain treatment — it is reserved for hospitalized patients unable to take oral medication.

Methadone is also used for the detoxification and maintenance treatment of opioid addiction (dependence on heroin or other morphine-like drugs). Oral forms — including tablets, dispersible tablets (such as Methadose Dispersible and DISKETS), and oral concentrates (such as Methadone Hydrochloride Intensol™, Methadose, and others) — are approved for this use. By law, methadone for opioid addiction treatment must be dispensed only by certified opioid treatment programs. Injectable methadone is not approved for outpatient addiction treatment.

See full Methadone 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
111Minor
2,689No known interaction
29 Moderate 111 Minor 2,689 No interaction
Moderate

29 interactions

Minor

111 interactions

Showing 60 of 111 minor interactions — see all 111 on the Genistein Combined Polysaccharide page.

No interaction 2,689 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 2,689 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 Methadone, ranked by severity
Evidence & sources

Genistein Combined Polysaccharide References

The 2 references that drive our Genistein Combined Polysaccharide 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. Chen, Y., Xiao, C. Q., He, Y. J., Chen, B. L., Wang, G., Zhou, G., Zhang, W., Tan, Z. R., Cao, S., Wang, L. P., and Zhou, H. H. Genistein alters caffeine exposure in healthy female volunteers. Eur.J Clin.Pharmacol. 2011;67(4):347-353. PubMed
  2. Capodice JL, Cammack AS, McKiernan JM, Katz AE. Two case reports on the use of genistein combined polysaccharide (GCP) against bladder cancer recurrence. J Complement Integr Med 2011;8. PubMed

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 Genistein Combined Polysaccharide and Methadone Together: Common Questions

Is it safe to take Genistein Combined Polysaccharide with Methadone?
We do not list a known interaction between Genistein Combined Polysaccharide and Methadone. 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 Genistein Combined Polysaccharide and Methadone have any of the same side effects?
Yes — our sources link each of them separately to one 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.
How was the Genistein Combined Polysaccharide and Methadone combination checked?
Interactions in our licensed database are recorded against drug classes. Methadone is filed under 11 classifications, and Genistein Combined Polysaccharide has documented interactions with 2 drug classes — none of Methadone's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Genistein Combined Polysaccharide interact with any other medications?
Yes. Genistein Combined Polysaccharide has 140 documented drug interactions in our database — Methadone is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Methadone interact with any supplements?
Yes. Methadone has documented interactions with 223 supplements in our database — Genistein Combined Polysaccharide is not one of them. The Methadone 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

Genistein Combined Polysaccharide monograph Uses, safety profile, and every drug interaction in one place Methadone drug information The full plain-English guide to this medication Methadone supplement interactions Every supplement checked against Methadone, 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 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Methadone 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.