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Dietary supplement

Parsley 400 mg Ingredients & Drug Interactions

by Signature Supplements

Parsley 400 mg label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Parsley 400 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Parsley 400 mg is a dietary supplement by Signature Supplements with 1 active ingredient. Its ingredients are commonly taken for water retention and bloating, urinary and bladder support, digestive upset.Based on those ingredients, 443 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Parsley. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Parsley 400 mg by Signature Supplements

Ask about any prescription or over-the-counter medication and we check it for interactions with Parsley 400 mg by Signature Supplements — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Parsley 400 mg by Signature Supplements

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Parsley 400 mg contains one active ingredient: parsley leaf. You also get cellulose and diatomaceous earth as inactive ingredients to hold the capsule together.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Parsley's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: supports whole body health.
  • We looked for evidence on: digestive support, urinary health, antioxidant support, vitamin supplementation.
  • The closest evidence on file: Parsley is rated "Insufficient Reliable Evidence To Rate" for Urinary tract infections (UTIs) (Natural Medicines).

The evidence we hold doesn't establish that parsley works for urinary tract infections, melasma, osteoarthritis, insect bites, or skin cancer. All of these conditions show insufficient reliable evidence to rate its usefulness.

The evidence, ingredient by ingredient Parsley

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Parsley from food is generally well tolerated in normal eating amounts. But this is a concentrated supplement—at 400 mg per capsule, large doses may not be safe.

The serious concerns come at very high intakes (like 10 grams or more of parsley's toxic compounds apiole or myristicin, or 200 grams of parsley oil), which can cause hallucinations, low red blood cell counts (hemolytic anemia), low blood pressure, liver or kidney damage, and rare clotting disorders. Pregnancy is a caution: medicinal or large amounts may stimulate the uterus, so stick to food amounts only if you're pregnant or planning to be.

Breastfeeding safety data isn't on file for this supplement—talk with your doctor or pharmacist for personalized advice.

Side effects, ingredient by ingredient Parsley

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Parsley.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications.
  • For scale: 443 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Double-check this product if you take blood thinners or antiplatelet drugs, diabetes medications, water pills (diuretics), sedatives, or the transplant drug sirolimus before you start. If you take a blood thinner like warfarin or a drug that your liver processes through CYP1A2, that's especially important.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

This product is fine as occasional supplemental parsley if you don't take blood thinners, diabetes drugs, sedatives, diuretics, or the transplant drug sirolimus. If you do take any of those, check with us first.

Anyone with a parsley allergy should avoid it. Talk to your pharmacist about whether parsley makes sense for what you're trying to do.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Sep 25, 2025.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Parsley 400 mg, straight from the product label.

Brand Signature Supplements
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Sep 25, 2025
DSLD ID 338888
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Parsley 400 mg by Signature Supplements, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
50
IngredientAmount% DV
Parsley800 mg--

Other ingredients: Cellulose, Diatomaceous Earth

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formulation

Contains no: chemical fillers or binders, artificial coloring, artificial flavor, preservatives, yeast, corn, milk or milk derivatives, lactose, salt, sodium, soy, sugar, gluten, starch or wheat.

From a GMP Facility

Supports whole body health

Storage

Store in a dry place and avoid excessive heat.

FDA Statement of Identity

Dietary Supplement

Formula

Phytonutrient green food Natural whole herb

Suggested/Recommended/Usage/Directions

Directions: For adults, take two (2) capsules daily

Precautions

Warning: Pregnant or lactating women should consult a doctor before using any product. Consult doctor before use if you are taking any prescription medications including blood-thinners or daily aspirin, or if you have, or have had, a bleeding disorder, or if you plan to have surgery or have had recent surgery.

Discontinue use and consult your doctor if any adverse reactions occur, including gastrointestinal discomfort, headaches, rash, or eye problems.

Not intended for use by persons under the age of 18.

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Parsley 400 mg by Signature Supplements label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Parsley 400 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Parsley 400 mg by Signature Supplements

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container50 Amounts shown are per serving.

Parsley

Interacts with
443 drugs
800 mg per serving Form: Petroselinum crispum

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...

Parsley monograph & interactions

Other (inactive) ingredients: Cellulose, Diatomaceous Earth. These complete the product’s ingredient list but are not active constituents.

Interaction report

Parsley 400 mg by Signature Supplements Drug Interactions

Want to check YOUR meds against Parsley 400 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
443Drugs
443 Moderate

Ingredients driving the most interactions

Parsley 443

Individual Drug Interactions

The ingredients in Parsley 400 mg interact with 443 drugs. Click any drug to see the details.

1 of the 1 ingredient in Parsley 400 mg interact with drugs. Each result below shows which ingredient is responsible. Parsley

Each ingredient & the kinds of drugs it affects

For each ingredient in Parsley 400 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Parsley8 drug types · 443 drugs

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
Parsley full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Parsley 400 mg, from the product label.

Signature Supplements

See all Signature Supplements products
Name
Signature Supplements
Street Address
P.O. Box 1112
City
San Clemente
State
CA
Web Address
yoursignaturesupplements.com
Pharmacist Counseling Corner

Parsley 400 mg by Signature Supplements: Common Questions

Does Parsley 400 mg by Signature Supplements interact with any medications?
Yes. Based on its ingredients, Parsley 400 mg has a known interaction with 443 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Parsley 400 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is parsley safe in pregnancy?
Medicinal or large amounts of parsley may stimulate the uterus, so you should stick to normal food amounts only if you're pregnant. If you're thinking about taking this supplement while pregnant or trying to conceive, talk with your doctor or pharmacist first.
What are the side effects?
At normal doses, parsley is generally well tolerated. Very high doses may cause serious effects like hallucinations, low blood counts, kidney or liver problems, and clotting disorders—but those come from extreme amounts (10+ grams of parsley's toxic compounds or 200 grams of parsley oil). Rare cases of severe allergic reactions like anaphylaxis have been reported.
Can parsley help with urinary tract infections?
The evidence we hold doesn't establish whether parsley works for UTIs—there isn't enough reliable data to rate it one way or the other.
What is parsley actually used for in this supplement?
The product contains parsley leaf at 400 mg per capsule. We don't have evidence it's effective for the common uses (UTIs, skin conditions, joint pain), but parsley is traditionally used as a diuretic and for its nutritional compounds.
Is this safe if I have a parsley allergy?
No—avoid this supplement. If you have a known parsley allergy and take aspirin, the combination may worsen allergic reactions. Severe cases of anaphylaxis have been reported with parsley.

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

Not sure if Parsley 400 mg is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Parsley 400 mg label
Go deeper

The Full Monographs Behind Parsley 400 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Parsley

Interacts with 443 drugs

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 hu...

Read the full Parsley monograph →
Sources

Sources & How We Checked

Parsley 400 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 21 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Parsley 21 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  3. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  4. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  5. Robbers JE, Tyler VE. Tyler's Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York, NY: The Haworth Herbal Press, 1999.
  6. Foster S, Tyler VE. Tyler's Honest Herbal, 4th ed., Binghamton, NY: Haworth Herbal Press, 1999. DOI
  7. Eberhard P, Gall HM, Muller I, Moller R. Dramatic augmentation of a food allergy by acetylsalicylic acid. J Allergy Clin Immunol 2000;105:844 PubMed
  8. Tunali T, Yarat A, Yanardag R, et al. Effect of parsley (Petroselinum crispum) on the skin of STZ induced diabetic rats. Phytother Res 1999;13:138-41.. DOI
  9. Chuang CH, Doyle P, Wang JD, et al. Herbal medicines used during the first trimester and major congenital malformations: an analysis of data from a pregnancy cohort study. Drug Saf 2006;29:537-48. PubMed
  10. Ciganda C, and Laborde A. Herbal infusions used for induced abortion. J Toxicol.Clin Toxicol. 2003;41:235-239. PubMed
  11. Jakovljevic, V., Raskovic, A., Popovic, M., and Sabo, J. The effect of celery and parsley juices on pharmacodynamic activity of drugs involving cytochrome P450 in their metabolism. Eur.J Drug Metab Pharmacokinet. 2002;27(3):153-156. PubMed
  12. Kreydiyyeh, S. I. and Usta, J. Diuretic effect and mechanism of action of parsley. J Ethnopharmacol 2002;79(3):353-357. PubMed
  13. Yanardag, R., Bolkent, S., Tabakoglu-Oguz, A., and Ozsoy-Sacan, O. Effects of Petroselinum crispum extract on pancreatic B cells and blood glucose of streptozotocin-induced diabetic rats. Biol Pharm Bull. 2003;26(8):1206-1210. PubMed
  14. Bolkent, S., Yanardag, R., Ozsoy-Sacan, O., and Karabulut-Bulan, O. Effects of parsley (Petroselinum crispum) on the liver of diabetic rats: a morphological and biochemical study. Phytother.Res 2004;18(12):996-999.
  15. Ozsoy-Sacan, O., Yanardag, R., Orak, H., Ozgey, Y., Yarat, A., and Tunali, T. Effects of parsley (Petroselinum crispum) extract versus glibornuride on the liver of streptozotocin-induced diabetic rats. J Ethnopharmacol 3-8-2006;104(1-2):175-181. PubMed
  16. Peterson, S., Lampe, J. W., Bammler, T. K., Gross-Steinmeyer, K., and Eaton, D. L. Apiaceous vegetable constituents inhibit human cytochrome P-450 1A2 (hCYP1A2) activity and hCYP1A2-mediated mutagenicity of aflatoxin B1. Food Chem.Toxicol. 2006;44(9):147 PubMed
  17. Gadi, D., Bnouham, M., Aziz, M., Ziyyat, A., Legssyer, A., Legrand, C., Lafeve, F. F., and Mekhfi, H. Parsley extract inhibits in vitro and ex vivo platelet aggregation and prolongs bleeding time in rats. J Ethnopharmacol 8-17-2009;125(1):170-174. PubMed
  18. Arslan S, Ucar R, Caliskaner AZ. A Cases of Near-fatal Anaphylaxis: Parsley "Over-use" as an Herbal Remedy. Med Arch. 2014;68(6):426-7.
  19. Foti C, Cassano N, Mistrello G, Amato S, Romita P, Vena GA. Contact urticaria to raw arugula and parsley. Ann Allergy Asthma Immunol. 2011 May;106(5):447-8. PubMed
  20. Farzaei MH, Abbasabadi Z, Ardekani MR, Rahimi R, Farzaei F. Parsley: a review of ethnopharmacology, phytochemistry and biological activities. J Tradit Chin Med. 2013;33(6):815-26. PubMed
  21. Kurtaran M, Koc NS, Aksun MS, Yildirim T, Yilmaz SR, Erdem Y. Petroselinum crispum, a commonly consumed food, affects sirolimus level in a renal transplant recipient: a case report. Ther Adv Drug Saf 2021;12:20420986211009358.

See these in context on the Parsley monograph →

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

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