Herb & supplement monograph

Boldo Drug Interactions, Uses, Effectiveness, Safety & More

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

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

But these pages have grown well beyond that into a full monograph — what Boldo 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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Boldo 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 Boldo drug interaction is modest for most people, though a few closely monitored medicines deserve real caution. None of the listed interactions are rated major, but all are graded moderate, and nearly all rest on limited or theoretical evidence.

Interactions deserving the most attention

The best-documented concern is lithium: boldo may act as a mild diuretic, which could reduce how the body clears lithium and raise its levels. Tacrolimus also stands out, since one transplant patient with long-stable levels saw them drop below target while taking boldo, a change that could risk rejection. People on warfarin or other blood thinners should be watchful too, as one case tied a boldo and fenugreek combination to a higher INR. Boldo itself has been linked to liver injury, so combining it with other medicines that can stress the liver adds to that risk.

What the rest of the list means

The long list mostly reflects broad drug groups, not proven harm with each individual medicine. Most of these concerns come from lab or animal research or single case reports, and for many combinations a meaningful effect has not been confirmed in people.

Check your medications against Boldo

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

Interaction report

Drugs that interact with Boldo

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

2,830 drugs
6-mercaptopurinePurinethol
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + 6-mercaptopurine interaction 6-mercaptopurine drug page: uses, dosage & side effects
Abacavir Sulfate, Dolutegravir, LamivudineTriumeq
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Abacavir Sulfate, Dolutegravir, Lamivudine interaction Abacavir Sulfate, Dolutegravir, Lamivudine drug page: uses, dosage & side effects
Abacavir, LamivudineEpzicom
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Abacavir, Lamivudine interaction
AbciximabReoPro
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.

Read the full Boldo + Abciximab interaction
Abiraterone
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Abiraterone interaction Abiraterone drug page: uses, dosage & side effects
Abiraterone AcetateYonsa, Zytiga
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Abiraterone Acetate interaction Abiraterone Acetate drug page: uses, dosage & side effects
AbrocitinibCibinqo
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.

Read the full Boldo + Abrocitinib interaction Abrocitinib drug page: uses, dosage & side effects
AcarboseGlucobay, Prandase, Precose
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acarbose interaction Acarbose drug page: uses, dosage & side effects
AcebutololRhotral, Sectral
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acebutolol interaction Acebutolol drug page: uses, dosage & side effects
AcenocoumarolSintrom
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.

Read the full Boldo + Acenocoumarol interaction
AcetaminophenChildren's Tylenol, Children's Tylenol Meltaways, Tylenol, Tylenol Ex Strength
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen interaction Acetaminophen drug page: uses, dosage & side effects
Acetaminophen, AspirinGemnisyn
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Aspirin interaction
Acetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.

Read the full Boldo + Acetaminophen, Aspirin, Caffeine interaction
Acetaminophen, Brompheniramine, PhenylpropanolamineDimetapp Cold and Flu
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Brompheniramine, Phenylpropanolamine interaction
Acetaminophen, ButalbitalAxocet, Bancap, Bucet, Butex Forte, Esgic CF, Orbivan CF +5 more
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Butalbital interaction
Acetaminophen, Butalbital, CaffeineEsgic, Esgic Plus, Fiogesic, Fioricet, Repan, Tecnal +1 more
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Butalbital, Caffeine interaction Acetaminophen, Butalbital, Caffeine drug page: uses, dosage & side effects
Acetaminophen, Butalbital, Caffeine, CodeineEsgic with Codeine, Fioricet w/ Codeine
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Butalbital, Caffeine, Codeine interaction
Acetaminophen, Butalbital, CodeineBancap w/ Codeine
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Butalbital, Codeine interaction
Acetaminophen, Butalbital, Codeine PhosphatePhrenilin #3
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Butalbital, Codeine Phosphate interaction
Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interaction
Acetaminophen, Caffeine, CodeineGesic C15, Gesic C30, Gesic C8, Lenoltec 1, Lenoltec 2, Lenoltec 3 +1 more
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Caffeine, Codeine interaction
Acetaminophen, Caffeine, Codeine, SalicylamideCodalan No.1, Codalan No.2, Codalan No.3
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Caffeine, Codeine, Salicylamide interaction
Acetaminophen, Caffeine, DihydrocodeineDHC Plus, Panlor DC, Panlor SS
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Caffeine, Dihydrocodeine interaction
Acetaminophen, Caffeine, IsomethepteneMigralam
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Caffeine, Isometheptene interaction
Acetaminophen, Caffeine, PyrilamineMidol Max Strength Menstrual
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Caffeine, Pyrilamine interaction
Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan HbrVicks Formula 44M Cough, Cold & Flu Relief
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interaction
Acetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interaction
Acetaminophen, Chlorpheniramine, DextromethorphanCoricidin II Extra Strength Cold and Flu
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Chlorpheniramine, Dextromethorphan interaction
Acetaminophen, Chlorpheniramine, Dextromethorphan HydrobromideCoricidin HBP Maximum Strength Flu
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interaction
Acetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief
Moderate Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.

Read the full Boldo + Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interaction
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 Boldo 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 Boldo affects

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

All 5 drug categories Boldo interacts with
Anticoagulant/antiplatelet DrugsHepatotoxic DrugsLithiumTacrolimus (prograf)Warfarin (coumadin)
Anticoagulant/Antiplatelet Drugs

Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.
Animal and in vitro research shows that boldine, a constituent of boldo, has antiplatelet activity. In one case report, an adult taking a combination of boldo and fenugreek with warfarin experienced an increase in international normalized ratio (INR); however, it is unclear if this effect was due to boldo, fenugreek, the combination, or another factor.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.
Boldo leaf contains ascaridole, a known liver toxin. Many cases of hepatotoxicity, including elevated liver transaminase levels and jaundice, have been reported in patients taking boldo.

Likelihood Possible Evidence D
Lithium

Theoretically, taking boldo with lithium might increase the levels and clinical effects of lithium.
Boldo is believed to have diuretic effects. Theoretically, these diuretic effects might reduce the excretion of lithium. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
Tacrolimus (Prograf)

Taking boldo with tacrolimus may decrease the levels and clinical effects of tacrolimus, potentially increasing the risk of transplant rejection.
In one case report, a patient with a long-term history of stable tacrolimus levels developed subtherapeutic levels after taking boldo 300 mg twice daily orally for several weeks. Tacrolimus levels returned to normal after discontinuing boldo. However, the mechanism of this interaction is unclear.

Likelihood Possible Evidence D
Warfarin (Coumadin)

A combination of boldo and fenugreek was thought to be associated with an increased international normalized ratio (INR) in a female on warfarin. It is not clear if boldo, fenugreek, or the combination played a role in this interaction. Therefore, boldo may have additive effects with warfarin.

Likelihood Possible Evidence D
Monograph

Boldo: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Boldo is a South American shrub whose leaves are traditionally used for digestive and gallbladder complaints, but good human evidence is very limited. The leaves and oil contain ascaridole, which can be toxic to the liver, so only ascaridole-free products should be used and only for short periods. Talk to your pharmacist or doctor before trying it, and avoid it during pregnancy and breastfeeding.

Boldo
Scientific name
Peumus boldus
Family
Monimiaceae
Part used
Leaves and essential oil
Common forms
Tea, dried leaf, tincture, capsules, essential oil
People commonly use it for
  • Indigestion and bloating
  • Mild constipation
  • Liver and gallbladder support
  • Appetite stimulation
  • Urinary complaints

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

Safety at a glance
OverallUse caution

May be used short-term in low doses, but the ascaridole in the leaf and oil can harm the liver.

PregnancyPossibly Unsafe

When used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects. Also, the ascaridole const...

Read the full pregnancy detail
BreastfeedingPossibly Unsafe

When used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects. Also, the ascaridole const...

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

Boldo (Peumus boldus) is a small evergreen tree or shrub native to Chile and other parts of South America. It has small, leathery, dark green leaves with a strong, distinctive aroma. The leaves are the part used most often.

In its native region, boldo leaves are used both as a cooking herb and in traditional medicine. People most commonly take it as a tea or in capsules and tinctures for stomach and gallbladder complaints. The essential oil is much more concentrated and is generally not recommended for self-use.

How it works

The leaves contain an alkaloid called boldine, along with flavonoids and an essential oil. Boldine is thought to act as an antioxidant and may help the liver make and release bile, which could explain its traditional use for digestion and gallbladder complaints.

The essential oil also contains ascaridole, a compound that has been used as a wormer but can be toxic, especially to the liver. Most of these proposed effects come from test-tube and animal studies, so it is not clear how well they apply to people taking the herb.

Effectiveness

Does Boldo work?

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

Evidence overview · 5 uses evaluated
5 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 Boldo, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 5 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Benign prostatic hyperplasia (BPH)
Rating & evidence shown verbatim from Natural Medicines

Oral boldo has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Gallbladder disease
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral boldo for gallbladder disease, there is insufficient reliable information about the clinical effects of boldo for this purpose.

Insufficient Reliable Evidence To Rate Gonorrhea
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral boldo for gonorrhea, there is insufficient reliable information about the clinical effects of boldo for this purpose.

Insufficient Reliable Evidence To Rate Joint pain
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral boldo for joint pain, there is insufficient reliable information about the clinical effects of boldo for this purpose.

Insufficient Reliable Evidence To Rate Kidney stones (nephrolithiasis)
Rating & evidence shown verbatim from Natural Medicines

Oral boldo has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

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

The biggest concern with boldo is ascaridole, which is found in the leaves and especially the essential oil and can be toxic to the liver. Only ascaridole-free or low-ascaridole preparations should be used, and even then only for short periods and in low doses.

People with liver disease, blocked bile ducts, gallstones, or other gallbladder problems should avoid boldo unless a doctor approves it. The pure essential oil should not be taken internally. Stop using it and seek care if you notice yellowing of the skin or eyes, dark urine, or belly pain.

Pregnancy: Avoid boldo. It may stimulate the uterus and could be harmful. Breastfeeding: Avoid it, since there is not enough safety information. When in doubt, check with a pharmacist or doctor first.

Side effects

When used as a tea in small amounts, boldo is usually well tolerated. Possible side effects include stomach upset and, with the essential oil or high doses, more serious problems.

Rare but serious: Liver toxicity has been linked to boldo, mainly because of ascaridole. Taking too much, or using the essential oil, raises this risk. Watch for signs of liver trouble such as nausea, fatigue, dark urine, or jaundice, and get medical help if they occur.

Boldo: Reported Adverse Effects

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

Orally, boldo is generally well tolerated when used in amounts commonly found in foods. However, when used in medicinal amounts, boldo can cause significant adverse effects such as hepatotoxicity. There is currently a limited amount of information on the adverse effects of topical boldo; however, a thorough evaluation of safety outcomes has not been conducted.

Most Common Adverse Effects:

Orally: Abdominal pain, nausea, vomiting.

Topically: Dermatitis.

Severe Adverse Effects (Rare):

Orally: Hepatotoxicity, jaundice.

Reports by condition
Alcohol-related liver disease Hepatic

Orally, boldo is thought to potentially cause hepatotoxicity. The volatile oil from the boldo leaf contains the liver toxin, ascaridole. In one case report, a manufacturer of an herbal laxative reformulated their product to contain boldo. Within 5 months of switching to this reformulated product, an 82-year-old male with mild hepatic steatosis and very small gallbladder stones developed elevated liver transaminase levels. Levels normalized following discontinuation of the herbal product. Several other cases of hepatotoxicity have been reported in elderly patients who received infusions of boldo leaves. These patients presented with elevated liver transaminase and bilirubin levels, sometimes up to 200 times the upper limit of normal, as well as nausea, vomiting, anorexia, asthenia, and jaundice. Lab tests and symptoms normalized a few days after stopping boldo.

  1. Piscaglia F, Leoni S, Venturi A, et al. Caution in the use of boldo in herbal laxatives: a case of hepatotoxicity. Scand J Gastroenterol 2005;40:236-9.
  2. Ribeiro RJ, Silvestre C, Duarte C. Hidden risks of alternative medicines: a case of boldo-induced hepatotoxicity. J Diet Suppl 2017;14(2):186-90.
  3. Oliveira Sá A, Pimentel T, Oliveira N. Boldo-Induced Hepatotoxicity: A Case of Unexplained Jaundice. Eur J Case Rep Intern Med 2020;7(12):002116.
Anorexia Gastrointestinal

In one case report, a manufacturer of an herbal laxative reformulated their product to contain boldo. Within 5 months of switching to this reformulated product, an 82-year-old male developed abdominal discomfort with gastrointestinal upset including heartburn. In another case, a 72-year-old female reported nausea, vomiting, and anorexia, which were thought to be associated with hepatotoxic effects of a boldo infusion.

  1. Piscaglia F, Leoni S, Venturi A, et al. Caution in the use of boldo in herbal laxatives: a case of hepatotoxicity. Scand J Gastroenterol 2005;40:236-9.
  2. Ribeiro RJ, Silvestre C, Duarte C. Hidden risks of alternative medicines: a case of boldo-induced hepatotoxicity. J Diet Suppl 2017;14(2):186-90.
Dermatitis Dermatologic

Topically, boldo can be irritating when applied to the skin. In one case report, a healthy 64-year-old patient experienced allergic contact dermatitis in an airborne pattern on the face, arms, and dorsum of both hands following airborne exposure to boldo. After exposure to boldo was avoided, the dermatitis resolved.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Valdes R, Feuereisen A, Bellinghausen M. Allergic Contact Dermatitis to Boldo. Dermatitis 2021;32(2):e31-e32.
Obesity Cardiovascular

In one report, a 39-year-old obese female developed palpitations and syncope after taking a weight loss supplement containing a combination of boldo, dandelion, and bladderwrack for 3 weeks. The patient was found to have prolonged QT-interval on ECG and frequent episodes of sustained polymorphic ventricular tachycardia. It is not clear whether boldo, another ingredient, or the combination of ingredients is responsible for this adverse effect. The product was not analyzed to determine the presence of any potential toxic contaminants.

  1. Agarwal SC, Crook JR, Pepper CB. Herbal remedies -- how safe are they? A case report of polymorphic ventricular tachycardia/ventricular fibrillation induced by herbal medication used for obesity. Int J Cardiol 2006;106:260-1.
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 standardized dose for boldo, and products vary widely in strength and in how much ascaridole they contain. Because of this, it is best to follow the directions on the product label and use it only for short periods.

Choose products labeled as ascaridole-free when possible, and avoid the pure essential oil. Before starting boldo, check with a pharmacist or doctor, especially if you take other medicines or have a health condition.

Pregnancy & Breastfeeding

Boldo & Pregnancy

Possibly Unsafe

When used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects. Also, the ascaridole constituent of boldo is a liver toxin.

  1. Almeida ER, Melo AM, Xavier H. Toxicological evaluation of the hydro-alcohol extract of the dry leaves of Peumus boldus and boldine in rats. Phytother Res 2000;14(2):99-102.
  2. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

Boldo & Breastfeeding

Possibly Unsafe

When used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects. Also, the ascaridole constituent of boldo is a liver toxin.

  1. Almeida ER, Melo AM, Xavier H. Toxicological evaluation of the hydro-alcohol extract of the dry leaves of Peumus boldus and boldine in rats. Phytother Res 2000;14(2):99-102.
  2. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
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 10 references that drive our Boldo 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. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Lambert J, Cormier J. Potential interaction between warfarin and boldo-fenugreek. Pharmacotherapy 2001;21:509-12. PubMed
  3. Piscaglia F, Leoni S, Venturi A, et al. Caution in the use of boldo in herbal laxatives: a case of hepatotoxicity. Scand J Gastroenterol 2005;40:236-9. PubMed
  4. Agarwal SC, Crook JR, Pepper CB. Herbal remedies -- how safe are they? A case report of polymorphic ventricular tachycardia/ventricular fibrillation induced by herbal medication used for obesity. Int J Cardiol 2006;106:260-1. PubMed
  5. Teng, C. M., Hsueh, C. M., Chang, Y. L., Ko, F. N., Lee, S. S., and Liu, K. C. Antiplatelet effects of some aporphine and phenanthrene alkaloids in rabbits and man. J Pharm Pharmacol 1997;49(7):706-711. PubMed
  6. Carbajal R, Yisfalem A, Pradhan N, et al. Case report: Boldo (Peumus boldus) and tacrolimus interaction in a renal transplant patient. Transplant Proc 2014;46(7):2400-2. PubMed
  7. Almeida ER, Melo AM, Xavier H. Toxicological evaluation of the hydro-alcohol extract of the dry leaves of Peumus boldus and boldine in rats. Phytother Res 2000;14(2):99-102. DOI
  8. Ribeiro RJ, Silvestre C, Duarte C. Hidden risks of alternative medicines: a case of boldo-induced hepatotoxicity. J Diet Suppl 2017;14(2):186-90. PubMed
  9. Oliveira Sá A, Pimentel T, Oliveira N. Boldo-Induced Hepatotoxicity: A Case of Unexplained Jaundice. Eur J Case Rep Intern Med 2020;7(12):002116. PubMed
  10. Valdes R, Feuereisen A, Bellinghausen M. Allergic Contact Dermatitis to Boldo. Dermatitis 2021;32(2):e31-e32. 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

Brand directory

Brands that make products with Boldo

33 brands in our database make a supplement containing Boldo.

Product directory

Supplement products with Boldo

174 products in our database contain Boldo. Open any to see its full ingredient list and every drug interaction we check.

Pharmacist Counseling Corner

Boldo: Common Questions

What is Boldo used for, and does it work?
People use Boldo 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 Boldo interact with prescription medications?
Yes. We list 482 medications with a known interaction with Boldo. Use the checker above to see how Boldo interacts with a specific drug.
How are Boldo 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 Boldo 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 Boldo 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 Boldo used for?
It is traditionally used for indigestion, bloating, mild constipation, appetite, and to support the liver and gallbladder. Human evidence for these uses is limited.
Is Boldo safe to take?
It may be used short-term in small amounts, but the leaves and oil contain ascaridole, which can harm the liver. Use only ascaridole-free products, avoid the essential oil, and check with a healthcare professional first.
Can I take Boldo while pregnant or breastfeeding?
No. Boldo may stimulate the uterus and there is not enough safety information, so it should be avoided during pregnancy and breastfeeding.
Can I use Boldo essential oil?
Boldo essential oil is very concentrated and high in ascaridole, which can be toxic. It should not be taken internally for self-treatment.

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

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