Herb & supplement monograph

Parsley Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Parsley interacts with medications. The heart of this page is the interaction list — every drug Parsley is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Parsley is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

Check Parsley against your medication

Add one medication

✓ Supplement

Parsley

1 Your medication

Start typing any prescription or over-the-counter drug name.

Reviewed by licensed pharmacists Sourced from Natural Medicines

On this page

Parsley Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Parsley drug interaction appears low for most people, especially at the amounts used in food. None of the listed interactions are rated major, and nearly all rest on animal or lab research rather than confirmed effects in people.

Interactions deserving the most attention

The clearest human signal involves sirolimus, a transplant medicine with a narrow safety margin: one person's blood levels rose several-fold after drinking a parsley juice daily for a week, then returned to normal after stopping. Warfarin also deserves care, since parsley contains vitamin K, which could work against this blood thinner if large amounts are eaten. People on diabetes medications or blood thinners may want to watch blood sugar or bleeding signs, though these concerns come from animal studies only.

What the rest of the list means

Parsley's long interaction list looks bigger than it is. Most entries are theoretical, based on animal findings or lab studies suggesting parsley may affect an enzyme the body uses to clear certain medications. Those predicted effects have not been shown to cause meaningful problems in people, and normal culinary amounts are unlikely to matter for most medications.

Check your medications against Parsley

Based on HelloPharmacist’s Parsley interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Parsley

443 medications have a known interaction with Parsley, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Parsley using our pharmacist-reviewed interaction data.

AI summaries are generated from our Parsley interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Parsley combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Parsley affects

Every type of medication (drug category) Parsley is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 8 drug categories Parsley interacts with

Anticoagulant/antiplatelet DrugsAntidiabetes DrugsCytochrome P450 1a2 (cyp1a2) SubstratesDiuretic DrugsPentobarbital (nembutal)Sirolimus (rapamune)Warfarin (coumadin)Aspirin

Anticoagulant/Antiplatelet Drugs

Theoretically, parsley might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
Animal research suggests that parsley has antiplatelet effects.

Likelihood Possible Evidence D

Antidiabetes Drugs

Theoretically, parsley might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research suggests that parsley might decrease blood glucose. Monitor blood glucose levels closely. Dose adjustments might be necessary.

Likelihood Possible Evidence D

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, parsley might increase serum levels of CYP1A2 substrates.
Laboratory research suggests that parsley can inhibit CYP1A2.

Likelihood Possible Evidence D

Diuretic Drugs

Theoretically, parsley might enhance or interfere with the effects of diuretic drugs.
Animal research suggests that parsley seed extract increases urine elimination. Parsley leaf and root might also interfere with diuretic therapy due their purported aquaretic effects.

Likelihood Possible Evidence D

Pentobarbital (Nembutal)

Theoretically, parsley might increase the duration of pentobarbital effects.
Animal research suggests that parsley juice prolongs the action of pentobarbital, perhaps by decreasing cytochrome P450 levels. It is not known if this occurs in humans or if this applies to other barbiturates or sedatives.

Likelihood Possible Evidence D

Sirolimus (Rapamune)

Theoretically, large quantities of parsley might increase sirolimus levels.
In one case report, an adult female with a history of kidney transplant presented with elevated blood sirolimus levels, approximately 4-7 times greater than previous measures, after daily consumption of a juice containing approximately 30 grams of parsley for 7 days. Sirolimus levels returned to normal a week after the parsley juice was discontinued.

Likelihood Possible Evidence D

Warfarin (Coumadin)

Theoretically, large amounts of parsley leaf and root might decrease the effects of warfarin.
Parlsey contains vitamin K.

Likelihood Possible Evidence D

Aspirin

Theoretically, aspirin might increase the severity of allergic reactions to parsley.
In one case, severe urticaria and swelling were reported after taking aspirin with parsley in an individual with a known mild parsley allergy.

Likelihood Unlikely Evidence D

Monograph

Parsley: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Parsley is a popular culinary herb that is safe to eat in normal food amounts and is a good source of vitamins K and C. It is traditionally used as a diuretic and for digestion, but solid human evidence for medicinal benefits is limited. Concentrated supplements, seed extracts, and the essential oil are much stronger than food and should be used cautiously, especially during pregnancy.

Scientific name: Petroselinum crispum
Family: Apiaceae
Part used: Leaves, seeds, root, and essential oil
Common forms: Fresh or dried herb, tea, capsules, extracts, seed oil, essential oil

People commonly use it for

Water retention and bloating
Urinary and bladder support
Digestive upset
Freshening breath
Source of vitamins and antioxidants

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Safe as a food, but concentrated extracts, seeds, and essential oil may not be safe in large amounts.

PregnancyLikely Unsafe

When used orally in medicinal amounts. Parsley has been used orally as an abortifacient and to stimulate menstrual flow. Population evidence suggests...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Parsley (Petroselinum crispum) is a leafy green herb native to the Mediterranean region and now grown all over the world. It is one of the most common cooking herbs, used fresh or dried to season foods. There are flat-leaf and curly-leaf types, plus a root variety often called Hamburg parsley.

Beyond the kitchen, parsley has a long history in traditional medicine. The leaves, seeds, root, and an essential oil pressed from the plant have all been used. People most often take it as a tea, in capsules, or as an extract for things like fluid retention, digestion, and general "detox" support.

How it works

Parsley contains several plant compounds that may be active, including flavonoids (such as apigenin), volatile oils (such as myristicin and apiole), and vitamins K and C. These are thought to have antioxidant effects in the body.

The traditional diuretic effect may come from compounds that affect how the kidneys handle sodium and water. However, most of what we know about these mechanisms comes from laboratory and animal research, not large human trials, so the real-world effects in people are uncertain.

Effectiveness

Does Parsley work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 12 uses evaluated

12 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

For Parsley, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 12 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Abortion