Drug & supplement interaction

Cowslip + Rilonacept

Rilonacept brand name: Arcalyst.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Cowslip and Rilonacept 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

Cowslip and Rilonacept

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 Rilonacept and Cowslip 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 Cowslip at all — not against Rilonacept, 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.

Cowslip safety at a glance

Cowslip overall Use caution Generally used in traditional teas, but human safety data are limited and some people may have allergic reactions.
Pregnancy Avoid Not enough safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety while breastfeeding is unknown, so avoid use.

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

Still wondering about combining Rilonacept and Cowslip? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Rilonacept’s Own FDA Label Lists

This is not an interaction — none of it involves Cowslip. These are the most notable effects listed in the ADVERSE REACTIONS section of Rilonacept’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. 6 of them are worth acting on rather than waiting out — marked below.

  • Bleeding in the gut Worth acting on
  • Hives Worth acting on
  • A low white blood cell count Worth acting on
  • Bleeding or bruising Worth acting on
  • A higher chance of infection Worth acting on
  • An allergic reaction Worth acting on
  • Sore throat
  • Cough
  • Stomach upset
  • Itching

Showing the 10 most notable of 15 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 Rilonacept. Read the label on DailyMed › Cowslip’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Cowslip side to compare — that is a limit of the record, not a statement that Cowslip has no side effects.

One more smart check

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

We hold 21 real supplement products containing Cowslip, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cowslip. Even though Cowslip itself has no known interaction with Rilonacept, 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 Cowslip and Rilonacept 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 Cowslip
Steady interest

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

29 days ago today
Medication Rilonacept
Steady interest

#2,254 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 Cowslip reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Cowslip and Rilonacept 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 Cowslip

What is Cowslip?

  • Cough and chest congestion
  • Bronchitis and sinus problems
  • Trouble sleeping
  • Anxiety and restlessness
  • Headache

Cowslip is a traditional European herb whose flowers and roots have long been used as a tea or syrup, mainly for coughs and congestion. Solid human studies are very limited, so its benefits are not well proven. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Primula veris · Primulaceae · Flowers and roots · Tea, tincture, syrup, capsules, dried herb

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

Cowslip: dosing

There is no well-established standardized dose for cowslip. Traditional use has involved teas made from the flowers or preparations of the root, but reliable dosing information from research is lacking.If you choose to use a cowslip product, follow the directions on the product label and do not exceed the suggested amount.

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

Read the full Cowslip monograph & all interactions
Medication

About Rilonacept Injection

What Is Rilonacept Injection Used For?

Brand name: Arcalyst

Arcalyst (rilonacept) is approved to treat Cryopyrin-Associated Periodic Syndromes (CAPS) — including Familial Cold Autoinflammatory Syndrome (FCAS) and Muckle-Wells Syndrome (MWS) — in adults and children 12 and older. It is also used to maintain remission of Deficiency of Interleukin-1 Receptor Antagonist (DIRA) in adults and children weighing at least 10 kg (about 22 lbs).

Arcalyst is also approved to treat recurrent pericarditis (repeated episodes of inflammation around the heart) and to lower the risk of it coming back, in adults and children 12 and older.

Most-Reported Side Effects for Rilonacept

From FAERS, the FDA’s public side-effect reporting system (1,121 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Injection site erythema 132 reports
Chest pain 115 reports
Fatigue 89 reports
Injection site pain 87 reports
Pericarditis 84 reports
See full Rilonacept Injection drug information
Keep checking

Other Drugs & Cowslip

Browse every other medication we’ve checked against Cowslip — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Cowslip References

The 3 references that drive our Cowslip 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. Neubauer N, Marz RW. Placebo-controlled, randomized, double-blind, clincal trial with Sinupret sugar coated tablets on the basis of a therapy with antibiotics and decongestant nasal drops in acute sinusitis. Phytomedicine 1994;1:177-81.
  2. Marz RW, Ismail C, Popp MA. Action profile and efficacy of a herbal combination preparation for the treatment of sinusitis. Wien Med Wochenschr 1999;149:202-8.
  3. Peric A, Kovacevic SV, Gacesa D, Peric AV. Efficacy and safety of combined treatment of acute rhinosinusitis by herbal medicinal product Sinupret and mometasone furoate nasal spray. ENT Updates 2017;7(2):68-74. DOI

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 Cowslip and Rilonacept Together: Common Questions

Is it safe to take Cowslip with Rilonacept?
We do not list a known interaction between Cowslip and Rilonacept. 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.

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

Still Have a Question About Rilonacept and Cowslip?

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.