Drug & supplement interaction

Acacia Rigidula + Fulvestrant

Fulvestrant brand name: Faslodex.

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 Acacia Rigidula and Fulvestrant 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

Acacia Rigidula and Fulvestrant

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 Fulvestrant and Acacia Rigidula 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.

Acacia Rigidula safety at a glance

Acacia Rigidula overall Avoid Some products contain an unapproved synthetic stimulant (BMPEA), and human safety data are lacking.
Pregnancy Avoid Not enough safety information; stimulant content makes it unsafe to use during pregnancy.
Breastfeeding Avoid No reliable safety data; avoid while breastfeeding.

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

Still wondering about combining Fulvestrant and Acacia Rigidula? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Fulvestrant

Interactions in our licensed database are recorded against drug classes, not just single drug names. Fulvestrant is filed under a single classification. Acacia Rigidula has documented interactions with 3 drug classes — the most serious being cytochrome p450 2d6 (cyp2d6) substrates (moderate), cytochrome p450 3a4 (cyp3a4) substrates (moderate) and stimulant drugs (moderate) — and none of Fulvestrant’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

Acacia Rigidula Does Interact With Other Medications

Acacia Rigidula has 813 moderate known drug interactions in our database — Fulvestrant isn’t one of them. If you take anything else, check it against the full list below.

Moderate 813 No known interaction 2,017 (incl. Fulvestrant)
Taking anything else?

Check Another of Your Medications Against Acacia Rigidula

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

What to actually watch for

What Acacia Rigidula Itself Has Been Linked To

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

  • A fast or pounding heartbeat Additional detail

    “There have been several reported cases of tachycardia and palpitations and one reported case of cardiac arrest in patients taking supplements containing Acacia rigidula and other stimulant ingredients. It is unclear if these adverse effects were due to Acacia rigidula or other stimulant ingredients in the supplements.”

    Acacia Rigidula · Natural Medicines adverse-effect record, reported in cardiac arrest.

    1 source cited
    1. 21079. Venhuis B, Keizers P, van Riel A, de Kaste D. A cocktail of synthetic stimulants found in a dietary supplement associated with serious adverse events. Drug Test Anal. 2014 Jun;6(6):578-81. doi: 10.1002/dta.1664. Epub 2014 May 6. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Acacia Rigidula — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Fulvestrant’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Fulvestrant column appears here.

Everything else you take

See Every Supplement That Interacts With Fulvestrant

This page covers Acacia Rigidula only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fulvestrant page lists 1 supplement it has a documented interaction with, worst first, each one explained.

The most serious there right now: Dhea (moderate).

By severity: 1 moderate.

Open the Fulvestrant interaction page

How much people look this up

Where Acacia Rigidula and Fulvestrant 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 Acacia Rigidula
Top half

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

29 days ago today
Medication Fulvestrant
Steady interest

#1,971 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 Acacia Rigidula reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Acacia Rigidula and Fulvestrant records this page draws on were last updated July 10, 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 Acacia Rigidula

What is Acacia Rigidula?

Acacia Rigidula
  • Weight loss
  • Energy and stimulation
  • Boosting metabolism
  • Appetite control
  • Pre-workout/athletic performance

Acacia rigidula is a shrub from Texas and Mexico that is marketed in weight-loss and energy supplements. There is very little reliable human evidence that it works, and some products have been found to contain an unapproved stimulant drug (BMPEA), which raises real safety concerns. Most people should avoid it and talk to a pharmacist or doctor before trying any product containing it.

Vachellia rigidula · Fabaceae · Leaves and stems · Capsules, tablets, powders (often in weight-loss and pre-workout blends)

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

Acacia Rigidula: dosing

There is no established or proven safe dose for Acacia rigidula. Given the safety concerns, many pharmacists would recommend avoiding these products altogether.

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

Read the full Acacia Rigidula monograph & all interactions
Medication

About Fulvestrant Injection

What Is Fulvestrant Injection Used For?

Brand name: Faslodex

Fulvestrant injection treats hormone receptor (HR)-positive advanced breast cancer in postmenopausal women. It can be used alone for women who have not yet had endocrine (hormone-blocking) therapy, or for women whose cancer has grown despite endocrine therapy.

It is also used in combination with other medicines — palbociclib, abemaciclib, or ribociclib — for HR-positive, HER2-negative advanced or metastatic breast cancer in women whose disease has progressed after endocrine therapy. Fulvestrant injection combined with ribociclib may also be used as an initial hormone-based treatment in this setting.

Most-Reported Side Effects for Fulvestrant

From FAERS, the FDA’s public side-effect reporting system (32,843 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Malignant neoplasm progression 4,229 reports
Fatigue 4,182 reports
Nausea 3,029 reports
Diarrhea 2,623 reports
Neutropenia 2,485 reports
See full Fulvestrant Injection drug information
Keep checking

Other Drugs & Acacia Rigidula

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

0Major
813Moderate
0Minor
2,016No known interaction
813 Moderate 2,016 No interaction
Moderate

813 interactions

Showing 60 of 813 moderate interactions — see all 813 on the Acacia Rigidula page.

No interaction 2,016 drugs checked — show the list

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

Showing the 60 most looked-up of 2,016 medications checked with no known interaction — see the full Acacia Rigidula list.

See the full Acacia Rigidula interactions page
See every supplement checked against Fulvestrant, ranked by severity
Evidence & sources

Acacia Rigidula References

The 4 references that drive our Acacia Rigidula 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. Pawar RS, Grundel E, Fardin-Kia AR, Rader JI. Determination of selected biogenic amines in Acacia rigidula plant materials and dietary supplements using LC-MS/MS methods. J Pharm Biomed Anal. 2014 Jan;88:457-66. doi: 10.1016/j.jpba.2013.09.012. Epub 2013 PubMed
  2. Venhuis B, Keizers P, van Riel A, de Kaste D. A cocktail of synthetic stimulants found in a dietary supplement associated with serious adverse events. Drug Test Anal. 2014 Jun;6(6):578-81. doi: 10.1002/dta.1664. Epub 2014 May 6. PubMed
  3. Cohen PA, Bloszies C, Yee C, Gerona R. An amphetamine isomer whose efficacy and safety in humans has never been studied, ß-methylphenylethylamine (BMPEA), is found in multiple dietary supplements. Drug Test Anal. 2015 Apr 7. PubMed
  4. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. 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 Acacia Rigidula and Fulvestrant Together: Common Questions

Is it safe to take Acacia Rigidula with Fulvestrant?
We do not list a known interaction between Acacia Rigidula and Fulvestrant. 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 Acacia Rigidula and Fulvestrant combination checked?
Interactions in our licensed database are recorded against drug classes. Fulvestrant is filed under 1 classification, and Acacia Rigidula has documented interactions with 3 drug classes — none of Fulvestrant'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 Acacia Rigidula interact with any other medications?
Yes. Acacia Rigidula has 813 documented drug interactions in our database — Fulvestrant 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 Fulvestrant interact with any supplements?
Yes. Fulvestrant has documented interactions with 1 supplement in our database — Acacia Rigidula is not one of them. The Fulvestrant 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

Acacia Rigidula monograph Uses, safety profile, and every drug interaction in one place Fulvestrant Injection drug information The full plain-English guide to this medication Fulvestrant supplement interactions Every supplement checked against Fulvestrant, 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 Fulvestrant and Acacia Rigidula?

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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.