Herb & supplement monograph

Scotch Broom Drug Interactions, Uses, Safety & More

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

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

But these pages have grown well beyond that into a full monograph — what Scotch Broom 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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Scotch Broom Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, Scotch Broom drug interactions carry a real risk of serious harm for people taking certain medications, so this is not a low-risk supplement. Nearly all of the listed interactions are rated major, and none are minor.

Interactions deserving the most attention

The biggest concerns involve haloperidol and quinidine, which can block the body's ability to clear sparteine, a natural chemical in Scotch Broom, raising the risk of dangerous effects on circulation. Scotch Broom flower also contains tyramine, so combining it with MAOIs (monoamine oxidase inhibitors) could trigger a sudden, severe rise in blood pressure. There is also a moderate concern with lithium, a narrow-margin medicine, because Scotch Broom may act as a diuretic and cause lithium levels to build up.

What the rest of the list means

This is a short interaction list, but it is weighted toward serious outcomes rather than minor ones. The evidence behind these warnings comes mostly from smaller human studies and reports rather than large trials, so the interactions are not fully proven. Even so, because the possible harms are severe, these combinations deserve genuine caution rather than reassurance.

Check your medications against Scotch Broom

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

Interaction report

Drugs that interact with Scotch Broom

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

11 major interactions. These combinations can be clinically significant — best avoided, or used only with close professional supervision. Always check with your pharmacist before combining them with Scotch Broom.

2,830 drugs
AmphetamineAdensys XR-ODT, Adzenys ER, Dyanavel XR, Mydayis› HaloperidolHaldol› IsocarboxazidMarplan› MoclobemideManerix, Moclobemide› Ozanimod HydrochlorideZeposia› Phenelzine SulfateNardil› QuinidineCardioquin, Cin-Quin, Duraquin, Lin-Qin, Quinova, Quinaglute, Quinaglute Duratabs +2 more› RasagilineAzilect› Safinamide MesylateXadago› SelegilineCarbex, Eldepryl, Emsam, Zelapar› TranylcypromineParnate› Lithium Carbonate (prescription Drug)Eskalith, Lithium Carbonate› "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›
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 Scotch Broom 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 Scotch Broom affects

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

All 4 drug categories Scotch Broom interacts with
Haloperidol (haldol)Monoamine Oxidase Inhibitors (maois)QuinidineLithium
Haloperidol (Haldol)

Haloperidol (Haldol) inhibits sparteine metabolism, increasing the risk of adverse effects including circulatory collapse.

Likelihood Probable Evidence D
Monoamine Oxidase Inhibitors (Maois)

Scotch broom flower contains tyramine. Combined use with MAOIs might cause a hypertensive crisis.

Likelihood Probable Evidence D
Quinidine

Quinidine (Quinidex) inhibits the metabolism of sparteine, a constituent of Scotch broom. This might increase levels of sparteine and increase the risk of adverse effects, including circulatory collapse.

Likelihood Probable Evidence D
Lithium

Scotch broom is thought to have diuretic properties. Theoretically, due to these potential diuretic effects, scotch broom might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
Monograph

Scotch Broom: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Scotch Broom is a flowering shrub that has been used in folk medicine for heart and circulation complaints, but it contains potentially toxic alkaloids and there is no solid scientific evidence that it works for any condition. Because it can affect heart rate and blood pressure and may be dangerous in higher amounts, most people should avoid it, and it should never be used during pregnancy or breastfeeding. Always talk with a pharmacist or doctor before trying it.

Scientific name
Cytisus scoparius
Family
Fabaceae
Part used
Flowering tops and aerial parts
Common forms
Tea, tincture, dried herb, occasionally capsules
People commonly use it for
  • Heart rhythm and circulation complaints
  • Diuretic (increasing urine)
  • Heavy menstrual bleeding
  • Mild swelling
  • Traditional folk remedy

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

Safety at a glance
OverallBest avoided

It contains toxic alkaloids and may affect the heart, so most people should avoid it.

PregnancyLikely Unsafe

When used orally; Scotch broom appears to be an abortifacient.

Read the full pregnancy detail
BreastfeedingLikely Unsafe

When used orally; 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

Scotch Broom (Cytisus scoparius) is a woody, flowering shrub in the legume (pea) family. It has bright yellow flowers and grows wild in parts of Europe and has spread to North America, Australia, and other regions, where it is often considered an invasive weed.

In traditional and folk medicine, the flowering tops and other above-ground parts of the plant have been used to make teas and tinctures. People historically used these preparations for heart rhythm problems, circulation issues, and as a diuretic to increase urine flow. Today it is rarely recommended because of safety concerns.

Uses & effectiveness

People have traditionally used Scotch Broom for irregular heartbeat, low blood pressure, fluid buildup, and heavy menstrual bleeding. It has also been used as a diuretic and a folk remedy for various complaints.

The scientific evidence for these uses is very limited. Most of what is known comes from old traditional use and from laboratory studies of its chemical compounds, not from well-designed human trials. There is not enough reliable evidence to show that Scotch Broom is safe or effective for any health condition. Because it contains compounds that affect the heart, using it for self-treatment of heart problems is risky.

How it works

Scotch Broom contains plant alkaloids, most notably sparteine, along with other compounds. Sparteine has been studied for its effects on the heart and has historically been linked to changes in heart rhythm and muscle contractions of the uterus.

The plant also contains substances that may act as a mild diuretic. These proposed effects are mainly based on laboratory research, animal studies, and older pharmacology, rather than modern human studies. The amounts of active compounds can vary a lot from plant to plant, which makes the effects unpredictable and hard to control.

Safety & precautions

Scotch Broom is generally considered unsafe for routine use. Its alkaloids, including sparteine, can affect heart rate and rhythm and can be toxic, especially in larger amounts. Poisoning has been reported with overuse.

People with heart conditions, abnormal heart rhythms, high or low blood pressure, or kidney problems should not use it. It should be avoided in children and in anyone who is medically fragile.

Pregnancy: Avoid. Compounds in Scotch Broom may stimulate the uterus and could be harmful. Breastfeeding: Avoid. There is not enough safety information, and the plant contains toxic compounds. Because of these risks, always check with a pharmacist or doctor before considering this herb.

Side effects

Reported and possible side effects include nausea, vomiting, dizziness, and changes in heart rate or blood pressure. Because it can act as a diuretic, it may also affect fluid and salt balance.

In larger amounts, Scotch Broom can be toxic. Serious effects may include dangerous changes in heart rhythm. If someone takes too much or develops symptoms like a racing or irregular heartbeat, fainting, or severe vomiting, seek medical care right away.

Scotch Broom: Reported Adverse Effects

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

Scotch broom is generally regarded as unsafe for use. Any benefits of therapy may not outweigh the risk of toxicity. Orally, the sparteine constituent of Scotch broom can cause toxicity at doses greater than 300 mg of sparteine, which is roughly equivalent to 30 grams of Scotch broom. Symptoms of toxicity include dizziness, headache, palpitations, prickling in the extremities, a feeling of weakness in the legs, sweating, sleepiness, pupil dilation, and ocular palsy. Scotch broom may cause nausea, diarrhea, vertigo, stupor, tachycardia with circulatory collapse, and respiratory arrest. Orally, the constituent sparteine has been shown to cause uterine contractions.

By inhalation, Scotch broom cigarettes may cause headaches and uterine stimulation. Smoking Scotch broom can also increase the risk of contracting pulmonary aspergillosis.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  4. Freeman, R. K. and Mishell, D. R., Jr. Induction of labor with sparteine sulfate for premature rupture of the fetal membranes near term. A double-blind study. Pac.Med Surg. 1968;76(1):43-47.
  5. Alexander, J. A. and Franklin, R. R. Effects of sparteine sulfate on uterine activity. Tex.Med 1966;62(8):54-56.
  6. Van Voorhis, L. W., Dunn, L. J., and Heggen, D. Effect of sparteine sulfate on amniotomy induction. A double blind evaluation. Am.J Obstet.Gynecol. 1-15-1966;94(2):230-233.
  7. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  8. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
Reports by condition
Cluster headache Neurologic/CNS

Orally, Scotch broom may cause vertigo and stupor. Toxicity from the sparteine constituent of Scotch broom can occur with doses greater than 300 mg of sparteine, which is roughly equivalent to 30 grams of Scotch broom. Predominant neurologic symptoms of toxicity include dizziness, headache, prickling in the extremities, a feeling of weakness in the legs, sweating, sleepiness, pupil dilation, and ocular palsy.

By inhalation, Scotch broom cigarettes may cause headaches.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
Diarrhea Gastrointestinal

Orally, toxicity from the sparteine constituent of Scotch broom can occur with doses greater than 300 mg of sparteine, which is roughly equivalent to 30 grams of Scotch broom. Predominant gastrointestinal symptoms of toxicity include nausea and diarrhea.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
Myasthenia gravis Cardiovascular

Orally, toxicity from the sparteine constituent of Scotch broom can occur with doses greater than 300 mg of sparteine, which is roughly equivalent to 30 grams of Scotch broom. Predominant cardiovascular symptoms of toxicity include palpitations, tachycardia with circulatory collapse, and respiratory arrest.

  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  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.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no established safe or standardized dose for Scotch Broom. Because the strength of the active alkaloids varies and the plant can be toxic, it is not possible to recommend a safe amount.

If a product contains Scotch Broom, follow the label exactly and do not exceed the directions. More importantly, talk with a pharmacist or doctor before using it, since for most people the safest choice is to avoid it altogether.

Pregnancy & Breastfeeding

Scotch Broom & Pregnancy

Likely Unsafe

When used orally; Scotch broom appears to be an abortifacient.

  1. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
  2. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
  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.

Scotch Broom & Breastfeeding

Likely Unsafe

When used orally; avoid using.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
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 11 references that drive our Scotch Broom 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. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  3. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
  4. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  5. Martindale W. Martindale the Extra Pharmacopoeia. Pharmaceutical Press, 1999.
  6. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  7. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  8. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  9. Freeman, R. K. and Mishell, D. R., Jr. Induction of labor with sparteine sulfate for premature rupture of the fetal membranes near term. A double-blind study. Pac.Med Surg. 1968;76(1):43-47.
  10. Alexander, J. A. and Franklin, R. R. Effects of sparteine sulfate on uterine activity. Tex.Med 1966;62(8):54-56.
  11. Van Voorhis, L. W., Dunn, L. J., and Heggen, D. Effect of sparteine sulfate on amniotomy induction. A double blind evaluation. Am.J Obstet.Gynecol. 1-15-1966;94(2):230-233. 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 Scotch Broom

2 brands in our database make a supplement containing Scotch Broom.

Product directory

Supplement products with Scotch Broom

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

Pharmacist Counseling Corner

Scotch Broom: Common Questions

Does Scotch Broom interact with prescription medications?
Yes. We list 12 medications with a known interaction with Scotch Broom, including 11 rated major. Use the checker above to see how Scotch Broom interacts with a specific drug.
How are Scotch Broom 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 Scotch Broom 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 Scotch Broom 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 Scotch Broom used for?
It has been used in folk medicine for heart rhythm and circulation problems, as a diuretic, and for heavy menstrual bleeding, but there is no solid evidence it works for any of these.
Is Scotch Broom safe to take?
It is generally considered unsafe because it contains toxic alkaloids that can affect the heart, and it can cause poisoning in larger amounts. Most people should avoid it.
Can I use Scotch Broom during pregnancy or breastfeeding?
No. It may stimulate the uterus and contains toxic compounds, so it should be avoided during pregnancy and breastfeeding.
What are the warning signs of taking too much?
Watch for a racing or irregular heartbeat, dizziness, fainting, or severe nausea and vomiting, and seek medical care right away if these occur.

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

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Products that contain Scotch Broom

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