Drug & supplement interaction

Couch Grass + Guselkumab

Guselkumab brand name: Tremfya.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Couch Grass and Guselkumab 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.

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Interaction report

Couch Grass and Guselkumab

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 Guselkumab and Couch Grass 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Couch Grass at all — not against Guselkumab, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Couch Grass safety at a glance

Couch Grass overall Use caution Generally considered well tolerated, but human safety data are limited.
Pregnancy Avoid Not enough safety information, so it is best avoided 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 Guselkumab and Couch Grass? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Guselkumab’s Own FDA Label Lists

This is not an interaction — none of it involves Couch Grass. These are the most notable effects listed in the ADVERSE REACTIONS section of Guselkumab’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 7 of them are worth acting on rather than waiting out — marked below.

  • A severe allergic reaction Worth acting on
  • Hives Worth acting on
  • A low white blood cell count Worth acting on
  • Liver problems Worth acting on
  • Bleeding or bruising Worth acting on
  • A higher chance of infection Worth acting on
  • An allergic reaction Worth acting on
  • Migraine
  • Sore throat
  • Numbness or tingling

Showing the 10 most notable of 19 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Guselkumab. Read the label on DailyMed › Where a percentage is shown, it is the share of 35,559 voluntary FDA FAERS reports for Guselkumab that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Couch Grass’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Couch Grass side to compare — that is a limit of the record, not a statement that Couch Grass has no side effects.

Everything else you take

See Every Supplement That Interacts With Guselkumab

This page covers Couch Grass only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guselkumab page lists 53 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Active Hexose Correlated Compound (ahcc) (moderate), Alfalfa (moderate), American Ginseng (moderate), Andrographis (moderate) and Ashwagandha (moderate).

By severity: 52 moderate · 1 minor.

From our pharmacist’s overview on the Guselkumab page

“Guselkumab (Tremfya) quiets an overactive branch of the immune system to control psoriasis and psoriatic arthritis, and all 53 supplements on this list interact the same way, by potentially revving that system back up. None is rated major, 52 are moderate and one is minor, so for most people this reads as a watch list rather than a sto…”

Reviewed by 2 · Jul 18, 2026

Open the Guselkumab interaction page

One more smart check

Taking Couch Grass as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,482 real supplement products containing Couch Grass, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Couch Grass. Even though Couch Grass itself has no known interaction with Guselkumab, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Couch Grass and Guselkumab 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 Couch Grass
Top 25%

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

29 days ago today
Medication Guselkumab
Steady interest

#2,524 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.
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Couch Grass and Guselkumab records this page draws on were last updated June 22, 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 Couch Grass

What is Couch Grass?

  • Urinary tract complaints
  • Mild bladder irritation
  • Increasing urine flow (diuretic)
  • Kidney 'gravel' or stones (traditional)
  • Soothing inflamed urinary passages
  • Sore throat or cough (traditional)

Couch grass is a common lawn weed whose rhizome has long been used in traditional European herbal medicine, mainly for urinary and bladder complaints. High-quality human studies are lacking, so its benefits are largely unproven. It is generally considered well tolerated, but you should talk to a pharmacist or doctor before using it, especially if you have kidney or heart problems.

Elymus repens · Poaceae · Dried rhizome (underground stem) and roots · Tea (infusion or decoction), liquid extract, tincture, capsules

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

Couch Grass: dosing

There is no well-established standardized dose of couch grass, because it has not been studied carefully in modern trials. Traditional preparations include teas made from the dried rhizome and liquid extracts or tinctures.The safest approach is to follow the directions on the product label and not exceed the recommended amount. If you take couch grass, drinking plenty of water is often advised, particularly when it is used for urinary complaints.

From our Couch Grass monograph — the full record covers uses, side effects and every documented interaction.

Read the full Couch Grass monograph & all interactions
Medication

About Guselkumab Injection

What Is Guselkumab Injection Used For?

Brand name: Tremfya

Tremfya (guselkumab) injection treats four conditions. For plaque psoriasis and psoriatic arthritis, Tremfya is approved for adults and children 6 years and older who weigh at least 40 kg (about 88 lbs) and who need systemic therapy or phototherapy. For ulcerative colitis and Crohn's disease, Tremfya is approved for adults with moderately to severely active disease.

For ulcerative colitis and Crohn's disease, Tremfya may be given by intravenous (IV) infusion during the initial treatment phase, then switched to subcutaneous (under-the-skin) injections for ongoing maintenance. For plaque psoriasis and psoriatic arthritis, Tremfya is given as subcutaneous injections only.

Most-Reported Side Effects for Guselkumab

From FAERS, the FDA’s public side-effect reporting system (35,559 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Needle issue 2,305 reports
Psoriasis 2,239 reports
Device issue 1,980 reports
Device malfunction 1,655 reports
Device deployment issue 1,495 reports
See full Guselkumab Injection drug information
Keep checking

Other Drugs & Couch Grass

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Couch Grass list.

See the full Couch Grass interactions page
See every supplement checked against Guselkumab, ranked by severity
Sources

Sources & How We Checked

We checked Couch Grass against Guselkumab in the Natural Medicines interaction database and found no documented interaction on file. The medication overview comes from MedlinePlus, and supplement label details from the NIH Dietary Supplement Label Database.

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
Couch Grass monograph › Uses, safety, and every drug interaction in one place Guselkumab supplement interactions › Every supplement checked against Guselkumab, ranked by severity Guselkumab Injection 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 Couch Grass and Guselkumab Together: Common Questions

Is it safe to take Couch Grass with Guselkumab?
We do not list a known interaction between Couch Grass and Guselkumab. 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.
Does Guselkumab interact with any supplements?
Yes. Guselkumab has documented interactions with 53 supplements in our database — Couch Grass is not one of them. The Guselkumab 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 Guselkumab and Couch Grass?

Our pharmacists answer your medication & supplement questions — free.

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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.