Herb & supplement monograph

Purple Nut Sedge Drug Interactions, Uses, Effectiveness, Safety & More

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

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

But these pages have grown well beyond that into a full monograph — what Purple Nut Sedge 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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Purple Nut Sedge 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 Purple Nut Sedge drug interaction appears low for most people. None of the listed interactions are rated major, and every one rests on lab or animal findings rather than documented effects in humans.

Interactions deserving the most attention

The combinations we would watch most closely involve medicines with little room for error. Lab research shows purple nut sedge can reduce platelet clumping, so it could add to the bleeding risk of anticoagulant and antiplatelet drugs such as warfarin, aspirin, or clopidogrel. Animal studies suggest it may lower blood glucose, which could strengthen diabetes medications and raise the chance of low blood sugar. It also appears to block an enzyme that breaks down acetylcholine, so it might add to the effects of cholinergic drugs like donepezil or work against anticholinergic drugs.

What the rest of the list means

Although hundreds of medications appear on this interaction list, that does not mean each pairing is harmful. Every concern here is theoretical, drawn from lab or animal research on how the plant might affect clotting, blood sugar, or a nerve-signaling enzyme. None has yet been confirmed to cause meaningful problems in people.

Check your medications against Purple Nut Sedge

Based on HelloPharmacist’s Purple Nut Sedge interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Purple Nut Sedge

424 medications have a known interaction with Purple Nut Sedge, graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
AbciximabReoPro› AbrocitinibCibinqo› AcarboseGlucobay, Prandase, Precose› AcenocoumarolSintrom› AcepromazineAtravet› Acetaminophen, AspirinGemnisyn› Acetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine› Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound› Acetaminophen, Caffeine, PyrilamineMidol Max Strength Menstrual› Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan HbrVicks Formula 44M Cough, Cold & Flu Relief› Acetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex› Acetaminophen, Chlorpheniramine, DextromethorphanCoricidin II Extra Strength Cold and Flu› Acetaminophen, Chlorpheniramine, Dextromethorphan HydrobromideCoricidin HBP Maximum Strength Flu› Acetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief› Acetaminophen, Chlorpheniramine, Dextromethorphan, PseudoephedrineChildren's Tylenol Cold Plus Cough, Tylenol Cold Ex Strength› Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, SalicylamideRhinogesic GG› Acetaminophen, Chlorpheniramine, PhenylephrineAlka-Seltzer PLUS, Histex SR, Protid› Acetaminophen, Chlorpheniramine, Phenylephrine, SalicylamideRhinogesic, Rhinogesic JR› Acetaminophen, Chlorpheniramine, PhenylpropanolamineAlumadrine, Conex, Sinadrin Max Strength, Sinulin› Acetaminophen, Chlorpheniramine, Phenylpropanolamine, OpiumHista-Derfule› Acetaminophen, Chlorpheniramine, Phenylpropanolamine, PhenyltoloxamineNorel Plus› Acetaminophen, Chlorpheniramine, PseudoephedrineAlka-Seltzer PLUS Liquid Gels, Children's Tylenol Cold, Codimal, Comtrex, Extra Strength Tylenol Allergy Sinus, Lorsin +3 more› Acetaminophen, Codeine, DoxylamineMersyndol› Acetaminophen, Dextromethorphan, Doxylamine, PseudoephedrineVicks NyQuil› Acetaminophen, Dextromethorphan, Phenylpropanolamine, PyrilamineTheracaps› Acetaminophen, DiphenhydramineTylenol PM, Tylenol PM Ex Strength› Acetaminophen, Diphenhydramine, PseudoephedrineChildren's Tylenol Allergy, Cold Control, Contac Night Allergy Relief› Acetaminophen, Doxylamine, PseudoephedrineEx Strength Tylenol Sinus Nighttime› Acetaminophen, IbuprofenCombogesic› Acetaminophen, Pamabrom, PyrilamineMidol Max Strength PMS, Pamprin, Pamprin ES›
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 Purple Nut Sedge 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 Purple Nut Sedge affects

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

All 4 drug categories Purple Nut Sedge interacts with
Anticholinergic DrugsAnticoagulant/antiplatelet DrugsAntidiabetes DrugsCholinergic Drugs
Anticholinergic Drugs

In vitro, purple nut sedge dose-dependently inhibits acetylcholinesterase (AChE). Theoretically, concurrent use of anticholinergic drugs and purple nut sedge might decrease the effectiveness of purple nut sedge or the anticholinergic agent.
Some anticholinergic drugs include atropine, benztropine (Cogentin), biperiden (Akineton), procyclidine (Kemadrin), and trihexyphenidyl (Artane).

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

In vitro, purple nut sedge inhibits platelet aggregation. Theoretically, purple nut sedge might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.
Some anticoagulant or antiplatelet drugs include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.

Likelihood Possible Evidence D
Antidiabetes Drugs

Evidence from animal research suggests that purple nut sedge can reduce blood glucose levels. Theoretically, purple nut sedge might have additive effects with antidiabetes drugs and increase the risk of hypoglycemia. Monitor blood glucose levels closely. Dose adjustments might be necessary.
Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), and others.

Likelihood Possible Evidence D
Cholinergic Drugs

In vitro, purple nut sedge dose-dependently inhibits acetylcholinesterase (AChE). Theoretically, concurrent use of purple nut sedge with cholinergic drugs might have additive effects and increase the risk of cholinergic side effects.
Cholinergic drugs include bethanechol (Urecholine), donepezil (Aricept), echothiophate (Phospholine Iodide), edrophonium (Enlon, Reversol, Tensilon), neostigmine (Prostigmin), physostigmine (Antilirium), pyridostigmine (Mestinon, Regonol), succinylcholine (Anectine, Quelicin), and tacrine (Cognex).

Likelihood Possible Evidence D
Monograph

Purple Nut Sedge: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Purple nut sedge (Cyperus rotundus) is a common weed whose tubers have a long history in Ayurvedic, Chinese, and other traditional medicine systems, mostly for digestive and menstrual complaints. Modern human evidence is very limited, so its benefits remain unproven. If you want to try it, talk with a pharmacist or doctor first, and avoid it during pregnancy and breastfeeding.

Scientific name
Cyperus rotundus
Family
Cyperaceae
Part used
Tubers (rhizomes) and essential oil
Common forms
Powder, capsules, decoction (tea), essential oil, traditional herbal formulas
People commonly use it for
  • Digestive upset and bloating
  • Menstrual cramps and irregular periods
  • Fever and inflammation
  • Skin and weight-related concerns
  • Antimicrobial uses

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

Safety at a glance
OverallUse caution

Traditional use is long, but high-quality human safety data are lacking.

PregnancyBest avoided

Traditionally used to affect menstruation, so avoid during pregnancy.

BreastfeedingBest avoided

There is not enough safety information, so it is best avoided.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Purple nut sedge (Cyperus rotundus) is a grass-like plant in the sedge family. It grows almost worldwide in warm regions and is one of the most widespread weeds on earth. Farmers often consider it a pest because it spreads quickly through its underground tubers.

Despite being a weed, the small, dark tubers (sometimes called "nut grass") have been used for centuries in Ayurvedic, traditional Chinese, and other folk medicine systems. The tubers have a slightly bitter, aromatic taste and are most often dried and made into powders, teas, or added to multi-herb formulas. An essential oil can also be steam-distilled from them.

How it works

The tubers contain a mix of natural compounds, including essential oils (with components such as cyperene and other terpenes), flavonoids, and other plant chemicals. In test-tube and animal research, extracts have shown possible antioxidant, anti-inflammatory, and antimicrobial activity.

These proposed actions are not the same as proven benefits in humans. The amounts and types of active compounds can also vary a lot depending on where the plant grows and how it is processed, so results from one study may not apply to a product on the shelf.

Effectiveness

Does Purple Nut Sedge work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 1 use evaluated
1 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 Purple Nut Sedge, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 1 condition — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Irritable bowel syndrome (IBS)
Rating & evidence shown verbatim from Natural Medicines

A small clinical study shows that taking an herbal mixture containing purple nut sedge tuber, English horsemint, and ginger three times daily for 8 weeks improves IBS symptoms including abdominal pain, stool frequency, stool consistency, incomplete evacuation, and urgency, when compared to baseline. These improvements are similar to those achieved by taking the antispasmodic mebeverine 135 mg three times daily. It is unclear if these effects are due to purple nut sedge, other ingredients, or the combination.

Sources Ref 89900

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Purple nut sedge has a long history of food and medicinal use, which is somewhat reassuring, but modern safety data in humans are very limited. Because product quality and strength can vary widely, it is hard to know exactly what you are getting.

Pregnancy: Avoid it. The herb has traditionally been used to bring on or regulate menstruation, which raises a theoretical concern during pregnancy. Breastfeeding: Avoid it as well, because there is not enough information to consider it safe. People with chronic health conditions, those taking prescription medicines, and anyone scheduled for surgery should check with a pharmacist or doctor before using it.

Side effects

Reported side effects are not well documented in modern medical literature. As with many herbal products, possible reactions include mild stomach upset or allergic reactions such as itching or rash.

Stop using the product and seek medical care if you notice signs of a serious allergic reaction, such as swelling of the face or throat, trouble breathing, or a widespread rash. Because supplements are not tightly regulated, there is also a risk of contamination or mislabeling, so choose products from reputable manufacturers.

Purple Nut Sedge: Reported Adverse Effects

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

There is currently a limited amount of information available about the adverse effects of purple nut sedge. Orally, purple nut sedge tuber seems to be generally well tolerated. In clinical research, purple nut sedge tuber 450 mg taken orally daily as a part of a combination product for 8 weeks did not cause adverse effects. Topically, purple nut sedge essential oil seems to be well-tolerated, except for a complaint of bad odor.

  1. Sahib AS. Treatment of irritable bowel syndrome using a selected herbal combination of Iraqi folk medicines. J Ethnopharmacol 2013;148(3):1008-12.
  2. Mohammed GF. Topical Cyperus rotundus oil: a new therapeutic modality with comparable efficacy to Alexandrite laser photo-epilation. Aesthet Surg J. 2014;34(2):298-305.
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 well-established or standardized dose for purple nut sedge. Traditional preparations vary widely, and the strength of capsules, powders, and oils differs from product to product.

If you choose to use it, follow the directions on the product label and start low. A pharmacist can help you review the product and decide whether it is appropriate for you. Do not use the essential oil internally unless directed by a qualified professional.

References & further reading

The 5 references that drive our Purple Nut Sedge 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. Seo EJ, Lee DU, Kwak JH, et al. Antiplatelet effects of Cyperus rotundus and its component (+)-nootkatone. J Ethnopharmacol. 2011;135(1):48-54. PubMed
  2. Raut NA, Gaikwad NJ. Antidiabetic activity of hydro-ethanolic extract of Cyperus rotundus in alloxan induced diabetes in rats. Fitoterapia. 2006;77(7-8):585-588. PubMed
  3. Sharma R, Gupta R. Cyperus rotundus extract inhibits acetylcholinesterase activity from animal and plants as well as inhibits germination and seedling growth in wheat and tomato. Life Sci. 2007;80(24-25):2389-2392. PubMed
  4. Sahib AS. Treatment of irritable bowel syndrome using a selected herbal combination of Iraqi folk medicines. J Ethnopharmacol 2013;148(3):1008-12. PubMed
  5. Mohammed GF. Topical Cyperus rotundus oil: a new therapeutic modality with comparable efficacy to Alexandrite laser photo-epilation. Aesthet Surg J. 2014;34(2):298-305. PubMed
Keep reading

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

Pharmacist Counseling Corner

Purple Nut Sedge: Common Questions

What is Purple Nut Sedge used for, and does it work?
People use Purple Nut Sedge for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.
Does Purple Nut Sedge interact with prescription medications?
Yes. We list 424 medications with a known interaction with Purple Nut Sedge. Use the checker above to see how Purple Nut Sedge interacts with a specific drug.
How are Purple Nut Sedge 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 Purple Nut Sedge 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 Purple Nut Sedge 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.
What is Purple Nut Sedge used for?
It is most often used in traditional medicine for digestive problems like bloating and cramps, and for menstrual complaints. However, strong human evidence supporting these uses is lacking.
Is Purple Nut Sedge safe to take?
It has a long history of traditional use, but there is little modern human safety data. Talk to a pharmacist or doctor first, especially if you take other medicines or have a health condition.
Can I use Purple Nut Sedge during pregnancy or while breastfeeding?
No. It is best avoided during both, since it has traditionally been used to affect menstruation and there is not enough safety information.
Is Purple Nut Sedge the same as the weed in my garden?
Yes, it is the same plant (Cyperus rotundus) considered a stubborn weed in many regions. Medicinal products use the dried underground tubers, but you should use a quality-controlled product rather than harvesting it yourself.

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

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