Drug & supplement interaction

Spanish 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 Spanish 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

Spanish 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 Spanish 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Spanish Broom at all — not against Interferon Beta-1a, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Spanish Broom safety at a glance

Spanish Broom overall Avoid The plant contains toxic alkaloids and can cause serious poisoning if taken internally.
Pregnancy Avoid Not safe; its alkaloids may affect the uterus and the developing baby.
Breastfeeding Possibly Unsafe When used orally because large amounts of the alkaloid constituent sparteine can stimulate menstrual flow. 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 Spanish Broom? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Spanish Broom Itself Has Been Linked To

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

  • Confusion Worth acting on Additional detail

    “Ingestion of Spanish broom flowers or seeds collected directly from the plant has been associated with cases of sedation, confusion, dizziness, headache, agitation, and tremors. In children aged 5-6 years, these symptoms occurred after ingesting 4-8 seeds, with the severity of the effects appearing to be dose-dependent.”

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

    2 sources cited
    1. 95934. Giménez N, Magro N, Cortés N, Guitart R. Poisoning after Ingestion of Spartium junceum Seeds: Dose-Dependent Effects in Three Boys. J Emerg Med. 2017;53(3):e41-e44. PubMed
    2. 95935. Riccardi A, Frumento F, Ghinatti M, Guiddo G, Lerza R. Spanish Broom flower ingestion: a very unusual poisoning. Eur J Emerg Med. 2006;13(5):317-8. PubMed
  • Drowsiness / Anxiety or restlessness / Dizziness / Headache Additional detail

    “Information on the adverse effects of Spanish broom is limited. Case reports describe toxicity in adults and children after ingestion of Spanish broom seeds or flowers collected directly from the plant. Symptoms include vomiting, abdominal pain, sedation, headache, dizziness, agitation, and tremors. Adverse effects have not been reported with use of flower extracts in the amounts allowed in foods in the US.”

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

    3 sources cited
    1. 95934. Giménez N, Magro N, Cortés N, Guitart R. Poisoning after Ingestion of Spartium junceum Seeds: Dose-Dependent Effects in Three Boys. J Emerg Med. 2017;53(3):e41-e44. PubMed
    2. 95935. Riccardi A, Frumento F, Ghinatti M, Guiddo G, Lerza R. Spanish Broom flower ingestion: a very unusual poisoning. Eur J Emerg Med. 2006;13(5):317-8. PubMed
    3. 4912. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  • Stomach pain / Vomiting Additional detail

    “Ingestion of Spanish broom flowers or seeds collected directly from the plant has been associated with abdominal pain, vomiting, diarrhea, and hypersalivation. In children aged 5-6 years, these symptoms occurred after ingesting 4-8 seeds, with the severity of the effects appearing to be dose-dependent.”

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

    2 sources cited
    1. 95934. Giménez N, Magro N, Cortés N, Guitart R. Poisoning after Ingestion of Spartium junceum Seeds: Dose-Dependent Effects in Three Boys. J Emerg Med. 2017;53(3):e41-e44. PubMed
    2. 95935. Riccardi A, Frumento F, Ghinatti M, Guiddo G, Lerza R. Spanish Broom flower ingestion: a very unusual poisoning. Eur J Emerg Med. 2006;13(5):317-8. PubMed
  • Diarrhea Additional detail

    Recorded for Spanish Broom in the same Natural Medicines adverse-effect record shown under Stomach pain / Vomiting above.

Everything above comes from the Natural Medicines adverse-effect record for Spanish 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

Spanish Broom in Pregnancy & Breastfeeding

Lactation Possibly Unsafe

When used orally because large amounts of the alkaloid constituent sparteine can stimulate menstrual flow.

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 Spanish 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

How much people look this up

Where Spanish 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 Spanish Broom
Steady interest

#1,341 of 1,452 supplements looked up here in the last 7 days

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

#2,320 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 Spanish Broom reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Spanish 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 Spanish Broom

What is Spanish Broom?

  • Diuretic ('water pill') effect
  • Heart and circulation complaints (folk use)
  • Mild laxative
  • Fragrance in perfumes and cosmetics
  • Traditional fiber and dye source

Spanish Broom is a Mediterranean flowering shrub used historically as a diuretic and heart remedy and today mostly as a perfume ingredient. It contains toxic alkaloids that can affect the heart and nervous system, and there is no reliable modern evidence that it is safe or effective for any health condition. Because of the poisoning risk, it is best avoided as an oral supplement.

Spartium junceum · Fabaceae · Flowers, and sometimes the flowering tops and seeds · Traditional teas or infusions, tinctures, and an essential oil (absolute) used in perfumery; rarely sold as a standardized supplement

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

Spanish Broom: dosing

There is no established safe dose for Spanish Broom as a supplement, and it is not recommended for internal use. Because the plant is toxic and its alkaloid content varies, no reliable, safe amount can be given.We do not provide a dose for this plant.

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

Read the full Spanish 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 & Spanish Broom

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Spanish Broom list.

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

Spanish Broom References

The 4 references that drive our Spanish 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. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  3. Giménez N, Magro N, Cortés N, Guitart R. Poisoning after Ingestion of Spartium junceum Seeds: Dose-Dependent Effects in Three Boys. J Emerg Med. 2017;53(3):e41-e44. PubMed
  4. Riccardi A, Frumento F, Ghinatti M, Guiddo G, Lerza R. Spanish Broom flower ingestion: a very unusual poisoning. Eur J Emerg Med. 2006;13(5):317-8. 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 Spanish Broom and Interferon Beta-1a Together: Common Questions

Is it safe to take Spanish Broom with Interferon Beta-1a?
We do not list a known interaction between Spanish 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.
Does Interferon Beta-1a interact with any supplements?
Yes. Interferon Beta-1a has documented interactions with 57 supplements in our database — Spanish 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

Spanish 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 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Interferon Beta-1a and Spanish 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.