Herb & supplement monograph

Watercress Drug Interactions, Uses, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

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

But these pages have grown well beyond that into a full monograph — what Watercress 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

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Watercress 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 Watercress drug interaction appears low for most people, though a few medications deserve real attention. Only a handful of medications interact with watercress, none of the interactions are rated major, and all are moderate in severity.

Interactions deserving the most attention

The best-documented concern involves the muscle relaxant chlorzoxazone. A human study found that eating watercress meaningfully raised chlorzoxazone levels and slowed its clearance, likely because watercress affects an enzyme the body uses to break down this drug, which could increase side effects. People taking warfarin should also be aware that watercress contains vitamin K, and eating large amounts could work against the blood thinner's effect, though this is less well documented. Finally, watercress may act as a mild diuretic, which in theory could raise lithium levels, but this is based on reasoning rather than human study.

What the rest of the list means

Not every interaction on this list carries the same weight. The chlorzoxazone finding comes from actual human research, while the lithium concern is theoretical and the warfarin concern mainly applies to eating watercress in large amounts. For most people, ordinary dietary use of watercress is unlikely to cause problems.

Check your medications against Watercress

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

Interaction report

Drugs that interact with Watercress

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

2,830 drugs
Acetaminophen, ChlorzoxazoneAcetazone Forte, Extra Strength Tylenol Aches & Strains, Parafon Forte› Acetaminophen, Chlorzoxazone, CodeineAcetazone Forte C8, Parafon Forte C8› ChlorzoxazoneParaflex, Parafon Forte DSC› Lithium Carbonate (prescription Drug)Eskalith, Lithium Carbonate› WarfarinWarfarin› Warfarin SodiumCoumadin, Panwarfin, Sofarin› "phentolamineOraVerse, Rogitine, Ryzumvi› 6-mercaptopurinePurinethol› Ado-trastuzumab EmtansineKadcyla› AbacavirZiagen› Abacavir Sulfate, Dolutegravir, LamivudineTriumeq› Abacavir, LamivudineEpzicom› AbaloparatideTymlos› AbametapirXeglyze› AbarelixPlenaxis› AbciximabReoPro› AbemaciclibVerzenio› Abiraterone› Abiraterone AcetateYonsa, Zytiga› AbrocitinibCibinqo› AcalabrutinibCalquence› AcamprosateCampral› AcarboseGlucobay, Prandase, Precose› AcebutololRhotral, Sectral› AcenocoumarolSintrom› AcepromazineAtravet› AcetaminophenChildren's Tylenol, Children's Tylenol Meltaways, Tylenol, Tylenol Ex Strength› Acetaminophen, AspirinGemnisyn› Acetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine› Acetaminophen, Brompheniramine, PhenylpropanolamineDimetapp Cold and Flu›
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 Watercress 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 Watercress affects

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

All 3 drug categories Watercress interacts with
Chlorzoxazone (parafon Forte, Paraflex)LithiumWarfarin (coumadin)
Chlorzoxazone (Parafon Forte, Paraflex)

Watercress might reduce the metabolism of chlorzoxazone and increase its effects and side effects. Clinical research in healthy volunteers shows that a single ingestion of watercress 50 grams increases the chlorzoxazone plasma concentration-time curve by about 56% and increases its half-life by about 53%.

Likelihood Probable Evidence B
Lithium

Watercress is thought to have diuretic properties. Theoretically, due to these potential diuretic effects, watercress might reduce excretion and increase levels of lithium.

Likelihood Probable Evidence D
Warfarin (Coumadin)

Watercress contains vitamin K. Consuming large amounts of watercress might antagonize the anticoagulant effects of warfarin.

Likelihood Possible Evidence B
Monograph

Watercress: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Watercress is a nutrient-rich leafy green that provides vitamins A, C, and K plus minerals and antioxidant plant compounds. Eaten as a food it is generally safe and healthy for most people, but strong human evidence for concentrated supplement health claims is limited. Talk to your pharmacist or doctor before using high-dose extracts, especially if you are pregnant, breastfeeding, or have a medical condition.

Watercress
Scientific name
Nasturtium officinale
Family
Brassicaceae
Part used
Leaves and stems (above-ground parts)
Common forms
Fresh leafy green, salad, juice, extract capsules, dried herb
People commonly use it for
  • Source of vitamins and minerals
  • Antioxidant support
  • General nutrition
  • Traditional cough and congestion remedy
  • Skin and detox tonics

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

Safety at a glance
OverallLikely safe

Generally safe as a food for most adults in normal culinary amounts.

PregnancyLikely Unsafe

When used in medicinal amounts. Watercress might stimulate menstruation or have abortifacient effects.

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

Watercress (Nasturtium officinale) is a leafy green plant in the mustard and cabbage family. It grows naturally in and around slow-moving fresh water like streams and springs, which is how it got its name. People have eaten it for centuries in salads, sandwiches, soups, and juices.

Watercress has a peppery, slightly sharp taste. It is best known as a nutritious vegetable that is low in calories but rich in vitamins and minerals. In recent years it has also been sold as a dietary supplement in capsule, powder, or extract form, mostly for its antioxidant plant compounds.

Uses & effectiveness

Most of the interest in watercress comes from its nutrient content. It is a good source of vitamin K, vitamin C, vitamin A (as beta-carotene), and some calcium, iron, and folate. As part of a balanced diet, vegetables like watercress are linked to good general health.

People also use watercress traditionally for coughs, congestion, as a "spring tonic," and for general wellness. Some laboratory and early studies have looked at its antioxidant and anti-inflammatory plant compounds, and a few small studies have explored effects on markers related to cell damage. However, this research is preliminary, and there is not enough strong human evidence to say that watercress prevents or treats any specific disease.

In short: watercress is a healthy food, but claims that watercress supplements treat conditions like cancer or chronic disease are not proven.

How it works

Watercress contains vitamins, minerals, and antioxidants such as vitamin C and carotenoids that may help protect cells from damage by unstable molecules called free radicals.

Like other plants in the cabbage family, it also contains glucosinolates, which the body can convert into compounds called isothiocyanates (one studied example is PEITC). In laboratory and animal studies, these compounds show antioxidant and anti-inflammatory activity. It is important to understand that effects seen in a test tube or in animals do not always carry over to people, so these mechanisms remain theoretical for human health benefits.

Safety & precautions

Eaten as a normal food, watercress is generally safe for most people. As a concentrated supplement or in large medicinal amounts, its safety is less well studied.

A few cautions to keep in mind:

  • Wild watercress: Watercress harvested from streams may be contaminated with bacteria or parasites from the water. Use commercially grown, washed watercress and wash it well.
  • Vitamin K: Watercress is high in vitamin K, which matters for people on blood thinners; keep your intake steady and talk to your healthcare provider.
  • Thyroid and stomach conditions: Large amounts of cabbage-family plants may not suit everyone; check with your doctor if you have a thyroid problem or sensitive stomach.

Pregnancy and breastfeeding: Eating normal food amounts is likely fine, but there is not enough reliable safety information on concentrated watercress supplements. To be safe, avoid medicinal or high-dose products during pregnancy and breastfeeding unless your doctor approves.

Side effects

For most people, watercress as a food causes few or no side effects. When eaten in large amounts, it may cause stomach upset, gas, or a burning feeling in the mouth or stomach because of its peppery compounds.

Some people may have an allergic reaction. If you notice rash, itching, swelling, or trouble breathing, stop using it and seek medical care. There is little information on the safety of long-term, high-dose watercress supplements.

Watercress: Reported Adverse Effects

Documented safety reports on Watercress from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally, watercress is well-tolerated when consumed in food amounts. There is limited reliable information available about the adverse effects of watercress when used in medicinal amounts. When excessive doses are used, watercress can cause gastrointestinal irritation. Consuming raw watercress has been associated with the development of fascioliasis, a parasitic fluke disease of the liver.

Topically, watercress can cause contact dermatitis.

  1. Gruenwald, J. PDR for Herbal Medicines. 1998;1st ed.
  2. Dobrucali, A., Yigitbasi, R., Erzin, Y., Sunamak, O., Polat, E., and Yakar, H. Fasciola hepatica infestation as a very rare cause of extrahepatic cholestasis. World J Gastroenterol. 10-15-2004;10(20):3076-3077.
  3. Yilmaz, H. and Godekmerdan, A. Human fasciolosis in Van province, Turkey. Acta Trop. 2004;92(2):161-162.
  4. Carrada-Bravo, T. [Fascioliasis: diagnosis, epidemiology and treatment]. Rev Gastroenterol.Mex. 2003;68(2):135-142.
  5. Cosme, A., Ojeda, E., Poch, M., Bujanda, L., Castiella, A., and Fernandez, J. Sonographic findings of hepatic lesions in human fascioliasis. J Clin Ultrasound 2003;31(7):358-363.
  6. Christmann, M., Henrich, R., Mayer, G., and Ell, C. [Infection with fasciola hepatica causing elevated liver-enzyme results and eosinophilia - serologic and endoscopic diagnosis and therapy]. Z.Gastroenterol. 2002;40(9):801-806.
  7. Cruz, Lopez O., Adan, Pimentel A., Tamariz Cruz, O. J., Munoz, Lopez A., Cruz Lopez, M. C., Cruz Lopez, M. E., and Munoz, Lopez S. [Hepatic fasciolasis diagnosed in state phase]. Rev Gastroenterol Mex. 2006;71(1):59-62.
  8. Dreyfuss, G., Vignoles, P., Abrous, M., and Rondelaud, D. Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France. Parasite 2002;9(2):113-120.
  9. Martinez-Bebert, K., Rodriguez-Baez, R., Pila-Perez, R., Pila-Pelaez, R., and Tamakloe, K. [Hepatic hematoma caused by fascioliasis]. Gac.Med Mex. 2002;138(3):271-274.
  10. Mailles, A., Capek, I., Ajana, F., Schepens, C., Ilef, D., and Vaillant, V. Commercial watercress as an emerging source of fascioliasis in Northern France in 2002: results from an outbreak investigation. Epidemiol.Infect. 2006;134(5):942-945.
  11. Cosme, A., Ojeda, E., Cilla, G., Torrado, J., Alzate, L., Beristain, X., Orive, V., and Arenas, J. [Fasciola hepatica. study of a series of 37 patients]. Gastroenterol.Hepatol. 2001;24(8):375-380.
  12. van Daele, P. L., Madretsma, G. S., and van Agtmael, M. A. [Stomach ache and fever after consumption of watercress in Turkey: fascioliasis]. Ned.Tijdschr.Geneeskd. 9-29-2001;145(39):1896-1899.
  13. Rondelaud, D., Dreyfuss, G., Bouteille, B., and Darde, M. L. Changes in human fasciolosis in a temperate area: about some observations over a 28-year period in central France. Parasitol.Res 2000;86(9):753-757.
  14. Sanchez-Sosa, S., Rojas-Ortega, S., Reed-San Roman, G., and Torres-Santana, M. A. [Massive hepatobiliary fascioliasis]. Rev Gastroenterol.Mex. 2000;65(4):179-183.
  15. Narain, K., Biswas, D., Rajguru, S. K., and Mahanta, J. Human distomatosis due to Fasciola hepatica infection in Assam, India. J Commun.Dis 1997;29(2):161-165.
  16. Alvarez-Chacon, R., Garcia-Rosales, J. J., de la Cruz-Otero MC, Wong-Chio, M., Cabrera-Bravo, M., Gomez-Gomez, J. V., and Gamez-Aranda, V. [Fascioliasis in children. A study of 10 cases]. Bol.Med Hosp.Infant Mex. 1992;49(6):365-371.
  17. de Gorgolas, M., Torres, R., Verdejo, C., Garay, J., Robledo, A., Ponte, M. C., and Fernandez Guerrero, M. L. [Fasciola hepatica infestation. Biopathology and new diagnostic and therapeutic aspects]. Enferm.Infecc.Microbiol.Clin 1992;10(9):514-519.
  18. Sapunar, J., Latorre, R., Guerra, M., and Defilippi, C. [Clinical considerations on 2 cases of hepatic fascioliasis. Importance of the imaging examinations]. Bol.Chil.Parasitol. 1992;47(3-4):70-76.
  19. el Shazly, A. M., Handousa, A. E., Youssef, M. E., Rizk, H., and Hamouda, M. M. Human fascioliasis: a parasitic health problem in Dakahlia Governorate, Egypt. J Egypt.Soc Parasitol. 1991;21(2):553-559.
  20. Borie, C., Corona, S., Garin, A., Olea, P., Salcedo, M., Perez, C., and Apt, W. [A family outbreak of acute hepatic fascioliasis]. Rev Med Chil. 1990;118(1):67-72.
  21. Cosme, A., Alzate, L., Orive, V., Recasens, M., Torrado, J., Ruiz, I., and Arenas, J. [Laparoscopic findings in liver fascioliasis. Study of 13 cases]. Rev Esp.Enferm.Dig. 1990;78(6):359-362.
  22. Delasalle, P., Beytout, J., Cambon, M., and Bommelaer, G. [Distomatosis: diagnosis and treatment]. Rev Prat. 1-21-1990;40(3):230-236.
  23. Diaz, J., Pina, B., Lastre, M., Rivera, L., and Perez, O. [Epidemic human fascioliasis. Cuba 1983. VI. Clinical study of 40 children in the Hospital Provincial of Sagua la Grande]. G.E.N. 1990;44(4):385-388.
  24. Rivera, J. V. and Bermudez, R. H. Radionuclide imaging of the liver in human fascioliasis. Clin Nucl.Med 1984;9(8):450-453.
  25. Bendezu, P., Frame, A., and Hillyer, G. V. Human fascioliasis in Corozal, Puerto Rico. J Parasitol. 1982;68(2):297-299.
  26. Croese, J., Chapman, G., and Gallagher, N. D. Evolution of fascioliasis after eating wild watercress. Aust.N.Z.J.Med. 1982;12(5):525-527.
  27. Derrick, E. and Darley, C. Contact dermatitis to nasturtium. Br.J Dermatol 1997;136(2):290-291.
  28. Diamond, S. P., Wiener, S. G., and Marks, J. G., Jr. Allergic contact dermatitis to nasturtium. Dermatol.Clin. 1990;8(1):77-80.
Reports by condition
Cirrhosis Hepatic

Raw, wild watercress can be contaminated with parasitic flukes which, when ingested, cause the liver disease fascioliasis. Symptoms include abdominal pain, fever, vomiting, diarrhea, urticaria, eosinophilia, and hepatomegaly. Clinical research shows that taking a standardized extract of watercress orally 750 mg/kg daily for 5 weeks is not associated with increases in liver function enzymes.

  1. Dobrucali, A., Yigitbasi, R., Erzin, Y., Sunamak, O., Polat, E., and Yakar, H. Fasciola hepatica infestation as a very rare cause of extrahepatic cholestasis. World J Gastroenterol. 10-15-2004;10(20):3076-3077.
  2. Yilmaz, H. and Godekmerdan, A. Human fasciolosis in Van province, Turkey. Acta Trop. 2004;92(2):161-162.
  3. Carrada-Bravo, T. [Fascioliasis: diagnosis, epidemiology and treatment]. Rev Gastroenterol.Mex. 2003;68(2):135-142.
  4. Cosme, A., Ojeda, E., Poch, M., Bujanda, L., Castiella, A., and Fernandez, J. Sonographic findings of hepatic lesions in human fascioliasis. J Clin Ultrasound 2003;31(7):358-363.
  5. Christmann, M., Henrich, R., Mayer, G., and Ell, C. [Infection with fasciola hepatica causing elevated liver-enzyme results and eosinophilia - serologic and endoscopic diagnosis and therapy]. Z.Gastroenterol. 2002;40(9):801-806.
  6. Cruz, Lopez O., Adan, Pimentel A., Tamariz Cruz, O. J., Munoz, Lopez A., Cruz Lopez, M. C., Cruz Lopez, M. E., and Munoz, Lopez S. [Hepatic fasciolasis diagnosed in state phase]. Rev Gastroenterol Mex. 2006;71(1):59-62.
  7. Dreyfuss, G., Vignoles, P., Abrous, M., and Rondelaud, D. Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France. Parasite 2002;9(2):113-120.
  8. Martinez-Bebert, K., Rodriguez-Baez, R., Pila-Perez, R., Pila-Pelaez, R., and Tamakloe, K. [Hepatic hematoma caused by fascioliasis]. Gac.Med Mex. 2002;138(3):271-274.
  9. Mailles, A., Capek, I., Ajana, F., Schepens, C., Ilef, D., and Vaillant, V. Commercial watercress as an emerging source of fascioliasis in Northern France in 2002: results from an outbreak investigation. Epidemiol.Infect. 2006;134(5):942-945.
  10. Cosme, A., Ojeda, E., Cilla, G., Torrado, J., Alzate, L., Beristain, X., Orive, V., and Arenas, J. [Fasciola hepatica. study of a series of 37 patients]. Gastroenterol.Hepatol. 2001;24(8):375-380.
  11. van Daele, P. L., Madretsma, G. S., and van Agtmael, M. A. [Stomach ache and fever after consumption of watercress in Turkey: fascioliasis]. Ned.Tijdschr.Geneeskd. 9-29-2001;145(39):1896-1899.
  12. Rondelaud, D., Dreyfuss, G., Bouteille, B., and Darde, M. L. Changes in human fasciolosis in a temperate area: about some observations over a 28-year period in central France. Parasitol.Res 2000;86(9):753-757.
  13. Sanchez-Sosa, S., Rojas-Ortega, S., Reed-San Roman, G., and Torres-Santana, M. A. [Massive hepatobiliary fascioliasis]. Rev Gastroenterol.Mex. 2000;65(4):179-183.
  14. Narain, K., Biswas, D., Rajguru, S. K., and Mahanta, J. Human distomatosis due to Fasciola hepatica infection in Assam, India. J Commun.Dis 1997;29(2):161-165.
  15. Alvarez-Chacon, R., Garcia-Rosales, J. J., de la Cruz-Otero MC, Wong-Chio, M., Cabrera-Bravo, M., Gomez-Gomez, J. V., and Gamez-Aranda, V. [Fascioliasis in children. A study of 10 cases]. Bol.Med Hosp.Infant Mex. 1992;49(6):365-371.
  16. de Gorgolas, M., Torres, R., Verdejo, C., Garay, J., Robledo, A., Ponte, M. C., and Fernandez Guerrero, M. L. [Fasciola hepatica infestation. Biopathology and new diagnostic and therapeutic aspects]. Enferm.Infecc.Microbiol.Clin 1992;10(9):514-519.
  17. Sapunar, J., Latorre, R., Guerra, M., and Defilippi, C. [Clinical considerations on 2 cases of hepatic fascioliasis. Importance of the imaging examinations]. Bol.Chil.Parasitol. 1992;47(3-4):70-76.
  18. el Shazly, A. M., Handousa, A. E., Youssef, M. E., Rizk, H., and Hamouda, M. M. Human fascioliasis: a parasitic health problem in Dakahlia Governorate, Egypt. J Egypt.Soc Parasitol. 1991;21(2):553-559.
  19. Borie, C., Corona, S., Garin, A., Olea, P., Salcedo, M., Perez, C., and Apt, W. [A family outbreak of acute hepatic fascioliasis]. Rev Med Chil. 1990;118(1):67-72.
  20. Cosme, A., Alzate, L., Orive, V., Recasens, M., Torrado, J., Ruiz, I., and Arenas, J. [Laparoscopic findings in liver fascioliasis. Study of 13 cases]. Rev Esp.Enferm.Dig. 1990;78(6):359-362.
  21. Delasalle, P., Beytout, J., Cambon, M., and Bommelaer, G. [Distomatosis: diagnosis and treatment]. Rev Prat. 1-21-1990;40(3):230-236.
  22. Diaz, J., Pina, B., Lastre, M., Rivera, L., and Perez, O. [Epidemic human fascioliasis. Cuba 1983. VI. Clinical study of 40 children in the Hospital Provincial of Sagua la Grande]. G.E.N. 1990;44(4):385-388.
  23. Rivera, J. V. and Bermudez, R. H. Radionuclide imaging of the liver in human fascioliasis. Clin Nucl.Med 1984;9(8):450-453.
  24. Bendezu, P., Frame, A., and Hillyer, G. V. Human fascioliasis in Corozal, Puerto Rico. J Parasitol. 1982;68(2):297-299.
  25. Croese, J., Chapman, G., and Gallagher, N. D. Evolution of fascioliasis after eating wild watercress. Aust.N.Z.J.Med. 1982;12(5):525-527.
  26. Clemente M, Miguel MD, Felipe KB, et al. Effect of watercress extract supplementation on lipid profile and oxidative stress markers in overweight people with physical disability: A randomized, double-blind, and placebo-controlled trial. Phytother Res. 202
Dermatitis Dermatologic

Topically, watercress can cause contact dermatitis, resulting in hives, rash, itching, or swollen skin.

  1. Derrick, E. and Darley, C. Contact dermatitis to nasturtium. Br.J Dermatol 1997;136(2):290-291.
  2. Diamond, S. P., Wiener, S. G., and Marks, J. G., Jr. Allergic contact dermatitis to nasturtium. Dermatol.Clin. 1990;8(1):77-80.
Myasthenia gravis Renal

Orally, excessive or prolonged use of watercress may theoretically cause kidney damage. However, in overweight adults with physical disabilities, taking a watercress extract 750 mg/kg daily for 5 weeks does not cause any change in levels of creatinine or urea.

  1. Brinker, F. Herb Contraindications and Drug Interactions. 1998;2nd edition.
  2. Clemente M, Miguel MD, Felipe KB, et al. Effect of watercress extract supplementation on lipid profile and oxidative stress markers in overweight people with physical disability: A randomized, double-blind, and placebo-controlled trial. Phytother Res. 202
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.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no official or standardized dose for watercress as a supplement. As a food, it is simply eaten in salads or cooked dishes in the amount you enjoy.

For capsules, powders, or extracts, follow the directions on the product label, since strength varies between products. More is not always better, and concentrated extracts have not been well studied for safety. If you are considering watercress supplements for a health reason, check with your pharmacist or doctor first.

Pregnancy & Breastfeeding

Watercress & Pregnancy

Likely Unsafe

When used in medicinal amounts. Watercress might stimulate menstruation or have abortifacient effects.

  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

Watercress & Breastfeeding

Insufficient reliable information

Insufficient reliable information available; avoid using.

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

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 34 references that drive our Watercress 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.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Leclercq I, Desager JP, Horsmans Y. Inhibition of chlorzoxazone metabolism, a clinical probe for CYP2E1, by a single ingestion of watercress. Clin Pharmacol Ther 1998;64:144-9. PubMed
  4. Bolton-Smith C, Price RJ, Fenton ST, et al. Compilation of a provisional UK database for the phylloquinone (vitamin K1) content of foods. Br J Nutr 2000;83:389-99.
  5. Rondelaud, D., Dreyfuss, G., Bouteille, B., and Darde, M. L. Changes in human fasciolosis in a temperate area: about some observations over a 28-year period in central France. Parasitol.Res 2000;86(9):753-757. PubMed
  6. Sanchez-Sosa, S., Rojas-Ortega, S., Reed-San Roman, G., and Torres-Santana, M. A. [Massive hepatobiliary fascioliasis]. Rev Gastroenterol.Mex. 2000;65(4):179-183.
  7. van Daele, P. L., Madretsma, G. S., and van Agtmael, M. A. [Stomach ache and fever after consumption of watercress in Turkey: fascioliasis]. Ned.Tijdschr.Geneeskd. 9-29-2001;145(39):1896-1899.
  8. Cosme, A., Ojeda, E., Cilla, G., Torrado, J., Alzate, L., Beristain, X., Orive, V., and Arenas, J. [Fasciola hepatica. study of a series of 37 patients]. Gastroenterol.Hepatol. 2001;24(8):375-380.
  9. Martinez-Bebert, K., Rodriguez-Baez, R., Pila-Perez, R., Pila-Pelaez, R., and Tamakloe, K. [Hepatic hematoma caused by fascioliasis]. Gac.Med Mex. 2002;138(3):271-274.
  10. Dreyfuss, G., Vignoles, P., Abrous, M., and Rondelaud, D. Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France. Parasite 2002;9(2):113-120.
  11. Christmann, M., Henrich, R., Mayer, G., and Ell, C. [Infection with fasciola hepatica causing elevated liver-enzyme results and eosinophilia - serologic and endoscopic diagnosis and therapy]. Z.Gastroenterol. 2002;40(9):801-806.
  12. Cosme, A., Ojeda, E., Poch, M., Bujanda, L., Castiella, A., and Fernandez, J. Sonographic findings of hepatic lesions in human fascioliasis. J Clin Ultrasound 2003;31(7):358-363. PubMed
  13. Sapunar, J., Latorre, R., Guerra, M., and Defilippi, C. [Clinical considerations on 2 cases of hepatic fascioliasis. Importance of the imaging examinations]. Bol.Chil.Parasitol. 1992;47(3-4):70-76.
  14. de Gorgolas, M., Torres, R., Verdejo, C., Garay, J., Robledo, A., Ponte, M. C., and Fernandez Guerrero, M. L. [Fasciola hepatica infestation. Biopathology and new diagnostic and therapeutic aspects]. Enferm.Infecc.Microbiol.Clin 1992;10(9):514-519.
  15. Carrada-Bravo, T. [Fascioliasis: diagnosis, epidemiology and treatment]. Rev Gastroenterol.Mex. 2003;68(2):135-142.
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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.

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

Brand directory

Brands that make products with Watercress

186 brands in our database make a supplement containing Watercress.

Product directory

Supplement products with Watercress

1,074 products in our database contain Watercress. Open any to see its full ingredient list and every drug interaction we check.

100% Fermented Organic Greens Organic Chocolate by Natural Factors Whole Earth & Sea Powder 7.7 Ounce(s) · 219 Gram(s) View ingredients & interactions 100% Fermented Organic Greens Unflavored by Natural Factors Whole Earth & Sea Powder 6.9 Ounce(s) · 195 Gram(s) View ingredients & interactions 50+ Women Multivitamin + Supporting Herbs by Super Nutrition SimplyOne Tablet Or Pill 90 Tablet(s) View ingredients & interactions Active Core Complex by JayLab Pro Capsule 60 Capsule(s) View ingredients & interactions Adrenal Support by Crystal Star Capsule 60 Vegetarian Capsule(s) View ingredients & interactions AdvaCleanse by Akasha Naturals Capsule 76 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 42 Capsule(s) View ingredients & interactions AdvaClear by Metagenics Capsule 126 Vegetarian Capsule(s) View ingredients & interactions Advanced Formula Hair, Skin & Nails by 21st Century Other (e.g. Tea Bag) 50 Caplet(s) View ingredients & interactions Alka Cleanse by B.E.S.T. Process Alka-Line Supplements Capsule 180 Capsule(s) View ingredients & interactions All Day Energy Green Zing by IVL Institute for Vibrant Living Powder 10 oz. · 285 g View ingredients & interactions All Day Energy Greens by IVL Institute For Vibrant Living Powder 11.36 oz. · 322 Gram(s) View ingredients & interactions All Day Energy Greens by IVL Powder 10.5 Ounce(s) · 300 Gram(s) View ingredients & interactions All Day Energy Greens by IVL Powder 10.5 Ounce(s) · 300 Gram(s) View ingredients & interactions All Day Energy Greens Fruity by IVL Powder 10.5 Ounce(s) · 300 Gram(s) View ingredients & interactions All Day Energy Greens Original Flavor by IVL Powder 10.5 Ounce(s) · 300 Gram(s) View ingredients & interactions Antioxidants by Pharmax Tablet Or Pill 30 Tablet(s) View ingredients & interactions
Pharmacist Counseling Corner

Watercress: Common Questions

Does Watercress interact with prescription medications?
Yes. We list 6 medications with a known interaction with Watercress. Use the checker above to see how Watercress interacts with a specific drug.
How are Watercress interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Watercress with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Watercress interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
Is Watercress good for you?
Yes, as a food it is a nutritious, low-calorie leafy green rich in vitamins A, C, and K and various minerals and antioxidants. Like other vegetables, it fits well into a healthy, balanced diet.
Does Watercress have proven health benefits as a supplement?
Watercress contains beneficial nutrients and plant compounds, but strong human evidence that Watercress supplements treat or prevent specific diseases is lacking. Most supporting research is from laboratory or animal studies.
Can I eat Watercress during pregnancy?
Normal food amounts of well-washed, commercially grown Watercress are generally considered fine, but concentrated supplements should be avoided because their safety in pregnancy is not well studied. Check with your doctor.
Is wild Watercress safe to eat?
Watercress picked from streams can carry harmful bacteria or parasites from the water. It is safer to use commercially grown Watercress and wash it thoroughly before eating.

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

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