Drug & supplement interaction

Fool's Parsley + Macitentan

Macitentan brand name: Opsumit.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Fool's Parsley and Macitentan 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

Fool's Parsley and Macitentan

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 Macitentan and Fool's Parsley 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 Fool's Parsley at all — not against Macitentan, 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.

Fool's Parsley safety at a glance

Fool's Parsley overall Avoid The raw plant is toxic and easily confused with edible parsley, so it should not be consumed.
Pregnancy Likely Unsafe When used orally due to potential for poisoning. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally due to potential for poisoning. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Macitentan and Fool's Parsley? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Macitentan’s Own FDA Label Lists

This is not an interaction — none of it involves Fool's Parsley. These are the most notable effects listed in the ADVERSE REACTIONS section of Macitentan’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.

  • Heart failure Worth acting on
  • Anemia Worth acting on
  • A severe allergic reaction Worth acting on
  • A higher chance of infection Worth acting on mentioned in 6.6% of FDA reports for Macitentan
  • Liver problems Worth acting on
  • An allergic reaction Worth acting on
  • Flushing
  • A stuffy or runny nose
  • Sore throat
  • Low blood pressure

Showing the 10 most notable of 14 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 Macitentan. Read the label on DailyMed › Where a percentage is shown, it is the share of 68,860 voluntary FDA FAERS reports for Macitentan that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Fool's Parsley’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Fool's Parsley side to compare — that is a limit of the record, not a statement that Fool's Parsley has no side effects.

Special populations

Fool's Parsley in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally due to potential for poisoning.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Macitentan

This page covers Fool's Parsley only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Macitentan page lists 253 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Beer (major) and Grapefruit (major).

By severity: 9 major · 205 moderate · 39 minor.

From our pharmacist’s overview on the Macitentan page

“If you take macitentan (Opsumit) for pulmonary arterial hypertension, study this page rather than skim it. It lists 253 supplement and herbal ingredients, nine rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Macitentan interaction page

How much people look this up

Where Fool's Parsley and Macitentan 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 Fool's Parsley
Steady interest

#1,171 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Macitentan
Top 25%

#507 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 Fool's Parsley reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Fool's Parsley and Macitentan 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 Fool's Parsley

What is Fool's Parsley?

  • Digestive complaints (traditional/homeopathic)
  • Diarrhea in children (homeopathic tradition)
  • Nausea and vomiting (homeopathic tradition)
  • Restlessness (homeopathic tradition)

Fool's Parsley is a poisonous weed that closely resembles edible parsley and has no proven medicinal benefit. The raw plant is toxic and should never be eaten; the only modern use is in highly diluted homeopathic products, which lack reliable evidence of effectiveness. If you are looking for a culinary herb, do not gather wild plants that resemble parsley.

Aethusa cynapium · Apiaceae · Whole plant (aerial parts), occasionally used in homeopathic preparations · Homeopathic dilutions; rarely as crude plant material (not recommended)

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

Fool's Parsley: dosing

There is no established safe medicinal dose of Fool's Parsley. The crude plant is poisonous and should not be taken at any amount.For homeopathic products, dosing follows the directions on the specific product label, but these are not standardized medical doses and are not supported by strong evidence.

From our Fool's Parsley monograph — the full record covers uses, side effects and every documented interaction.

Read the full Fool's Parsley monograph & all interactions
Medication

About Macitentan

What Is Macitentan Used For?

Brand name: Opsumit

Macitentan tablets — sold under the brand name Opsumit — are used to treat pulmonary arterial hypertension (PAH, WHO Group I), a type of high blood pressure in the arteries of the lungs. The goal is to slow the disease from getting worse and to lower the chance of being hospitalized because of PAH.

In the key clinical study, macitentan was used in adults with mainly moderate-to-severe PAH symptoms. Patients had PAH caused by unknown or inherited causes, connective tissue disorders, or congenital heart disease with repaired shunts.

Most-Reported Side Effects for Macitentan

From FAERS, the FDA’s public side-effect reporting system (68,860 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dyspnea 11,958 reports
Headache 8,323 reports
Diarrhea 6,584 reports
Nausea 5,972 reports
Fatigue 5,041 reports
See full Macitentan drug information
Keep checking

Other Drugs & Fool's Parsley

Browse every other medication we’ve checked against Fool's Parsley — 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 Fool's Parsley 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 Fool's Parsley list.

See the full Fool's Parsley interactions page
See every supplement checked against Macitentan, ranked by severity
Evidence & sources

Fool's Parsley References

The 1 references that drive our Fool's Parsley 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. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Fool's Parsley and Macitentan Together: Common Questions

Is it safe to take Fool's Parsley with Macitentan?
We do not list a known interaction between Fool's Parsley and Macitentan. 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 Macitentan interact with any supplements?
Yes. Macitentan has documented interactions with 253 supplements in our database — Fool's Parsley is not one of them. The Macitentan 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

Fool's Parsley monograph Uses, safety profile, and every drug interaction in one place Macitentan drug information The full plain-English guide to this medication Macitentan supplement interactions Every supplement checked against Macitentan, 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Macitentan and Fool's Parsley?

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.