Drug & supplement interaction

Genistein Combined Polysaccharide + Metaxalone

Metaxalone brand name: Skelaxin.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Genistein Combined Polysaccharide and Metaxalone 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 Metaxalone

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 Metaxalone 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 Metaxalone and Genistein Combined Polysaccharide? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Metaxalone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Metaxalone is filed under 2 classifications — skeletal muscle relaxants, oral 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 Metaxalone’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 — Metaxalone isn’t 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.

What to actually watch for

No Interaction Found — But Data Suggests Genistein Combined Polysaccharide and Metaxalone 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 reported in 5.9% of FDA reports for Metaxalone 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

    Metaxalone

    Listed in the ADVERSE REACTIONS section of the FDA label for Metaxalone, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

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

Effects for Metaxalone 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. Where a percentage is shown, it is the share of 3,328 voluntary FDA FAERS reports for Metaxalone that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. 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 Metaxalone

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 Metaxalone, 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 Metaxalone

This page covers Genistein Combined Polysaccharide only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metaxalone page lists 20 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Procaine (major), Coffee Charcoal (moderate), European Mandrake (moderate) and Glucomannan (moderate).

By severity: 2 major · 9 moderate · 9 minor.

From our pharmacist’s overview on the Metaxalone page

“Most of what interacts with metaxalone (Skelaxin), a muscle relaxant prescribed for painful muscle spasms, works by getting between the pill and your bloodstream. Fiber gums, mucilage herbs like slippery elm, and above all activated charcoal can bind or slow the drug in the gut, leaving you with less relief than your dose should deliver.”

Reviewed by 2 · Jul 18, 2026

Open the Metaxalone interaction page

How much people look this up

Where Genistein Combined Polysaccharide and Metaxalone 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

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

29 days ago today
Medication Metaxalone
Steady interest

#2,271 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 Metaxalone 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 Metaxalone

What Is Metaxalone Used For?

Brand name: Skelaxin

Metaxalone tablets are used to help relieve discomfort caused by acute (short-term), painful musculoskeletal conditions — things like muscle strains, sprains, and similar injuries. It is meant to be used together with rest, physical therapy, and other treatments, not as a stand-alone fix.

This use applies to adults and adolescents 13 years of age and older. Metaxalone tablets are available as the branded product Skelaxin and as a generic.

Most-Reported Side Effects for Metaxalone

From FAERS, the FDA’s public side-effect reporting system (3,328 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Completed suicide 261 reports
Nausea 198 reports
Fatigue 196 reports
Headache 172 reports
Toxicity to various agents 164 reports
See full Metaxalone 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
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
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 Metaxalone Together: Common Questions

Is it safe to take Genistein Combined Polysaccharide with Metaxalone?
We do not list a known interaction between Genistein Combined Polysaccharide and Metaxalone. 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 Metaxalone 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 Metaxalone combination checked?
Interactions in our licensed database are recorded against drug classes. Metaxalone is filed under 2 classifications, and Genistein Combined Polysaccharide has documented interactions with 2 drug classes — none of Metaxalone'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 — Metaxalone 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 Metaxalone interact with any supplements?
Yes. Metaxalone has documented interactions with 20 supplements in our database — Genistein Combined Polysaccharide is not one of them. The Metaxalone interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Metaxalone 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.