Drug & supplement interaction

Cowslip + Sorafenib

Sorafenib brand name: Nexavar.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated June 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Cowslip and Sorafenib 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 label for Sorafenib states a food rule worth keeping to.

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Interaction report

Cowslip and Sorafenib

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 Sorafenib 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 Sorafenib, 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 Sorafenib and Cowslip? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

What to actually watch for

What Sorafenib’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 Sorafenib’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. 4 of them are worth acting on rather than waiting out — marked below.

Raised blood pressure Worth acting on
Liver problems Worth acting on
Bleeding or bruising Worth acting on
A higher chance of infection Worth acting on
Weight loss
Reduced appetite mentioned in 7.0% of FDA reports for Sorafenib
Hair loss
Diarrhea mentioned in 14.3% of FDA reports for Sorafenib
Tiredness mentioned in 8.7% of FDA reports for Sorafenib
A skin rash mentioned in 7.1% of FDA reports for Sorafenib

Showing the 10 most notable of 11 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 Sorafenib. Read the label on DailyMed › Where a percentage is shown, it is the share of 20,576 voluntary FDA FAERS reports for Sorafenib that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. 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.

How to take them

Some Sorafenib Products Have a Food Rule — Cowslip Should Not Break It

At least one FDA label for a product containing Sorafenib says to take it on an empty stomach. Most supplements — Cowslip included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Sorafenib on its own and move Cowslip to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Sorafenib products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION The recommended dosage is 400 mg orally twice daily without food.

From the Dosage and Administration section of the FDA label we read for Sorafenib — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Sorafenib

This page covers Cowslip only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Sorafenib page lists 285 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Danshen (major), Grapefruit (major), Piracetam (major) and St. John's Wort (major).

By severity: 5 major · 241 moderate · 39 minor.

From our pharmacist’s overview on the Sorafenib page

“If you're on sorafenib (Nexavar) for cancer, be genuinely careful here, and learn the five major-rated entries first. Most of the 285 ingredients listed either have blood-thinning effects that stack onto sorafenib's bleeding risk (more than 200 do) or affect CYP3A4, the liver enzyme that clears the drug, pushing its level too high or t…”

Reviewed by 2 · Jul 18, 2026

Open the Sorafenib interaction page

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 Sorafenib, 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 Sorafenib 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

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

29 days ago today

Medication Sorafenib

Steady interest

#2,109 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 Sorafenib 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 Dr. Brian Staiger, PharmD, BCPS.

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 Sorafenib

What Is Sorafenib Used For?

Brand name: Nexavar

Sorafenib tablets are approved to treat three types of cancer. The first is unresectable hepatocellular carcinoma (HCC) — liver cancer that cannot be removed with surgery. The second is advanced renal cell carcinoma (RCC) — kidney cancer that has spread or progressed. Both the brand Nexavar and generic sorafenib tablets are approved for these two uses.

The third use is for locally recurrent or metastatic, progressive differentiated thyroid carcinoma (DTC) — thyroid cancer that has spread or worsened and no longer responds to radioactive iodine treatment. Nexavar and sorafenib tablets are both approved for this use as well.

See full Sorafenib 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

2,829 No interaction

No interaction 2,829 drugs checked — show the list

We also checked Cowslip 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 Cowslip list.

See the full Cowslip interactions page

See every supplement checked against Sorafenib, ranked by severity

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.

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.
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.
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 Sorafenib Together: Common Questions

Is it safe to take Cowslip with Sorafenib?

We do not list a known interaction between Cowslip and Sorafenib. 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.

Should I take Cowslip and Sorafenib at the same time of day?

At least one FDA label for a product containing Sorafenib says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Sorafenib on its own and move Cowslip to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.

Does Sorafenib interact with any supplements?

Yes. Sorafenib has documented interactions with 285 supplements in our database — Cowslip is not one of them. The Sorafenib 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

Cowslip monograph Uses, safety profile, and every drug interaction in one place Sorafenib drug information The full plain-English guide to this medication Sorafenib supplement interactions Every supplement checked against Sorafenib, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Sorafenib and Cowslip?

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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.