Drug & supplement interaction

Scotch Broom + Interferon Beta-1a

Interferon Beta-1a brand names: Rebif, Avonex.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Scotch Broom and Interferon Beta-1a in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Scotch Broom and Interferon Beta-1a

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Interferon Beta-1a and Scotch Broom in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Scotch Broom safety at a glance

Scotch Broom overall Avoid It contains toxic alkaloids and may affect the heart, so most people should avoid it.
Pregnancy Likely Unsafe When used orally; Scotch broom appears to be an abortifacient. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally; avoid using. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Interferon Beta-1a and Scotch Broom? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Interferon Beta-1a

Interactions in our licensed database are recorded against drug classes, not just single drug names. Interferon Beta-1a is filed under 2 classifications — photosensitizing drugs, hepatotoxic drugs. Scotch Broom has documented interactions with 4 drug classes — the most serious being haloperidol (haldol) (major), monoamine oxidase inhibitors (maois) (major) and quinidine (major) — and none of Interferon Beta-1a’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Scotch Broom Does Interact With Other Medications

Scotch Broom has 11 major, 1 moderate known drug interactions in our database — Interferon Beta-1a isn’t one of them. If you take anything else, check it against the full list below.

Major 11 Moderate 1 No known interaction 2,818 (incl. Interferon Beta-1a)
Taking anything else?

Check Another of Your Medications Against Scotch Broom

Covers the 2,830 medications we’ve checked against Scotch Broom. Pick one to open its full report.

What to actually watch for

What Scotch Broom Itself Has Been Linked To

This is not an interaction — nothing below involves Interferon Beta-1a. It is the side-effect record for Scotch Broom on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Scotch Broom, this list is the first place to look.

  • Sweating / Drowsiness / Dizziness / Headache Additional detail

    “Scotch broom is generally regarded as unsafe for use. Any benefits of therapy may not outweigh the risk of toxicity (4,12). 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.”

    Scotch Broom · Natural Medicines adverse-effect record, reported in cluster headache.

    6 sources cited
    1. 4. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
    2. 12. 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. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    4. 74000. 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. 74001. Alexander, J. A. and Franklin, R. R. Effects of sparteine sulfate on uterine activity. Tex.Med 1966;62(8):54-56.
    6. 74002. 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

    “Orally, Scotch broom may cause vertigo and stupor (4). 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.”

    Scotch Broom · Natural Medicines adverse-effect record, reported in cluster headache.

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

    “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 (18), tachycardia with circulatory collapse, and respiratory arrest (4).”

    Scotch Broom · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    2 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 4. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  • Diarrhea / Nausea Additional detail

    “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 (4).”

    Scotch Broom · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 4. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

Everything above comes from the Natural Medicines adverse-effect record for Scotch Broom — expand a row for the licensed statement it rests on. We haven’t matched Interferon Beta-1a to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Interferon Beta-1a.

Special populations

Scotch Broom in Pregnancy & Breastfeeding

Pregnancy Likely Unsafe

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

Lactation Likely Unsafe

When used orally; 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

Everything else you take

See Every Supplement That Interacts With Interferon Beta-1a

This page covers Scotch Broom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Interferon Beta-1a page lists 57 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Alfalfa (moderate) and Angelica Archangelica (moderate).

By severity: 3 major · 53 moderate · 1 minor.

From our pharmacist’s overview on the Interferon Beta-1a page

“Siberian cocklebur, an herb tied to documented cases of liver failure, is the first name to know for anyone injecting interferon beta-1a (Rebif, Avonex) for multiple sclerosis. Interferon beta-1a can strain the liver on its own, which is why prescribers order routine liver blood tests, and 38 of the 57 supplements on file carry that sa…”

Reviewed by 2 · Jul 18, 2026

Open the Interferon Beta-1a interaction page

One more smart check

Taking Scotch Broom as Part of a Dietary Supplement Product? Check It for Interactions

We hold 6 real supplement products containing Scotch Broom, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Scotch Broom. Even though Scotch Broom itself has no known interaction with Interferon Beta-1a, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Scotch Broom and Interferon Beta-1a Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Scotch Broom
Top half

#466 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Interferon Beta-1a
Steady interest

#2,614 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Scotch Broom reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Scotch Broom and Interferon Beta-1a records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Scotch Broom

What is Scotch Broom?

  • Heart rhythm and circulation complaints
  • Diuretic (increasing urine)
  • Heavy menstrual bleeding
  • Mild swelling
  • Traditional folk remedy

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.

Cytisus scoparius · Fabaceae · Flowering tops and aerial parts · Tea, tincture, dried herb, occasionally capsules

An interaction check asks whether these two react with each other — it does not ask whether Scotch Broom is a good idea for someone in your situation. Here is what our Scotch Broom record says about it on its own.

Scotch Broom: 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.

From our Scotch Broom monograph — the full record covers uses, side effects and every documented interaction.

Read the full Scotch Broom monograph & all interactions
Medication

About Interferon Beta-1a Intramuscular Injection

What Is Interferon Beta-1a Intramuscular Injection Used For?

Brand names: Rebif, Avonex

  • Interferon beta-1a intramuscular injection is used to treat adults with various forms of multiple sclerosis (MS; a disease in which the nerves do not function properly and people may experience weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control) including:

    • clinically isolated syndrome (CIS; nerve symptom episodes that last at least 24 hours),

    • relapsing-remitting forms (course of disease where symptoms flare up from time to time), or

    • secondary progressive forms (course of disease where relapses occur more often).

  • Interferon beta-1a is in a class of medications called immunomodulators. It works by decreasing inflammation and preventing nerve damage that may cause symptoms of multiple sclerosis.

Most-Reported Side Effects for Interferon Beta-1a

From FAERS, the FDA’s public side-effect reporting system (192,069 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Multiple sclerosis relapse 15,851 reports
Influenza like illness 13,253 reports
Fatigue 11,554 reports
Fall 10,604 reports
Multiple sclerosis 9,358 reports
See full Interferon Beta-1a Intramuscular Injection drug information
Keep checking

Other Drugs & Scotch Broom

Browse every other medication we’ve checked against Scotch Broom — both the ones with a known interaction and the ones without. Select any drug for the full detail.

11Major
1Moderate
0Minor
2,817No known interaction
11 Major 1 Moderate 2,817 No interaction
Major

11 interactions

Moderate

1 interaction

No interaction 2,817 drugs checked — show the list

We also checked Scotch Broom against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,817 medications checked with no known interaction — see the full Scotch Broom list.

See the full Scotch Broom interactions page
See every supplement checked against Interferon Beta-1a, ranked by severity
Evidence & sources

Scotch Broom References

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

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Scotch Broom and Interferon Beta-1a Together: Common Questions

Is it safe to take Scotch Broom with Interferon Beta-1a?
We do not list a known interaction between Scotch Broom and Interferon Beta-1a. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Scotch Broom and Interferon Beta-1a combination checked?
Interactions in our licensed database are recorded against drug classes. Interferon Beta-1a is filed under 2 classifications, and Scotch Broom has documented interactions with 4 drug classes — none of Interferon Beta-1a's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Scotch Broom interact with any other medications?
Yes. Scotch Broom has 12 documented drug interactions in our database — Interferon Beta-1a is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Interferon Beta-1a interact with any supplements?
Yes. Interferon Beta-1a has documented interactions with 57 supplements in our database — Scotch Broom is not one of them. The Interferon Beta-1a interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Scotch Broom monograph Uses, safety profile, and every drug interaction in one place Interferon Beta-1a Intramuscular Injection drug information The full plain-English guide to this medication Interferon Beta-1a supplement interactions Every supplement checked against Interferon Beta-1a, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 11 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Interferon Beta-1a and Scotch Broom?

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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.