Drug & supplement interaction

Hordenine + Fludarabine

Fludarabine brand name: Fludara.

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 Hordenine and Fludarabine 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Hordenine and Fludarabine

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 Fludarabine and Hordenine 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.

Hordenine safety at a glance

Hordenine overall Use caution Human safety data is very limited, and it acts as a stimulant.
Pregnancy Avoid No safety data; avoid use during pregnancy.
Breastfeeding Avoid No safety data; avoid while breastfeeding.

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

Still wondering about combining Fludarabine and Hordenine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Fludarabine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Fludarabine is filed under a single classification — oral drugs. Hordenine has documented interactions with 3 drug classes — the most serious being monoamine oxidase inhibitors (maois) (moderate), stimulant drugs (moderate) and cytochrome p450 2d6 (cyp2d6) substrates (minor) — and none of Fludarabine’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

Hordenine Does Interact With Other Medications

Hordenine has 180 moderate, 149 minor known drug interactions in our database — Fludarabine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 180 Minor 149 No known interaction 2,501 (incl. Fludarabine)
Taking anything else?

Check Another of Your Medications Against Hordenine

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

What to actually watch for

No Interaction Found — But Data Suggests Hordenine and Fludarabine May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • A fast or pounding heartbeat Additional detail

    Hordenine

    “No clinical studies have evaluated the safety of hordenine in humans. However, hordenine is structurally similar to the stimulants N-methyltyramine and synephrine, which are found in bitter orange. Theoretically, hordenine may cause stimulant-related side effects similar to these compounds, including tachycardia and hypertension.”

    Hordenine · Natural Medicines adverse-effect record, reported in hypertension.

    1 source cited
    1. 29888. Nelson BC, Putzbach K, Sharpless KE, Sander LC. Mass spectrometric determination of the predominant adrenergic protoalkaloids in bitter orange (Citrus aurantium). J Agric Food Chem 2007;55(24):9769-75. PubMed

    “Hordenine is structurally similar to the stimulants N-methyltyramine and synephrine, which are found in bitter orange. Theoretically, hordenine may cause stimulant-related side effects similar to these compounds, including tachycardia and hypertension. However, this has not been assessed or reported in humans.”

    Hordenine · Natural Medicines adverse-effect record, reported in hypertension.

    1 source cited
    1. 29888. Nelson BC, Putzbach K, Sharpless KE, Sander LC. Mass spectrometric determination of the predominant adrenergic protoalkaloids in bitter orange (Citrus aurantium). J Agric Food Chem 2007;55(24):9769-75. PubMed

    Fludarabine

    Listed in the ADVERSE REACTIONS section of the FDA label for Fludarabine. Read the label on DailyMed ›

Reported for Hordenine but not commonly for Fludarabine: raised blood pressure.

Effects for Fludarabine come from the ADVERSE REACTIONS section of its FDA label; effects for Hordenine come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Everything else you take

See Every Supplement That Interacts With Fludarabine

This page covers Hordenine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fludarabine page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Fludarabine page

“Someone taking fludarabine (Fludara) for leukemia is often dealing with nausea and digestive trouble at the same time, and that is exactly where this list bites. All 17 supplements and herbs on file interact the same basic way, by changing how much of an oral dose actually gets absorbed, and one of them, activated charcoal, rates major…”

Reviewed by 2 · Jul 18, 2026

Open the Fludarabine interaction page

One more smart check

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

We hold 339 real supplement products containing Hordenine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hordenine. Even though Hordenine itself has no known interaction with Fludarabine, 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 Hordenine and Fludarabine 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 Hordenine
Top 25%

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

29 days ago today
Medication Fludarabine
Steady interest

#1,459 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 Hordenine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Hordenine and Fludarabine 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 Hordenine

What is Hordenine?

Hordenine
  • Energy and stimulation
  • Athletic and workout performance
  • Weight loss/fat burning
  • Focus and mood
  • Appetite control

Hordenine is a natural alkaloid found in barley and some cacti that is marketed as a stimulant for energy, focus, and fat loss, but solid human evidence for these benefits is lacking. Its safety in people has not been well studied, so caution is warranted, and it should be avoided in pregnancy, breastfeeding, and by people with heart conditions.

Alkaloid isolated from plants such as barley sprouts and certain cacti · Capsules, tablets, powders (often in pre-workout and 'fat burner' blends)

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

Hordenine: dosing

There is no established, well-studied dose for hordenine. The amounts found in supplements vary widely, and they have not been tested for safety or effectiveness in proper human trials.If you choose to use a product containing hordenine, follow the label instructions and do not exceed them. Be aware that it is often mixed with caffeine and other stimulants, so the total stimulant load may be higher than it appears.

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

Read the full Hordenine monograph & all interactions
Medication

About Fludarabine Injection

What Is Fludarabine Injection Used For?

Brand name: Fludara

Fludarabine Injection is used to treat adult patients with B-cell chronic lymphocytic leukemia (CLL) — a cancer of the blood and bone marrow — whose disease did not respond to, or got worse during, at least one prior standard chemotherapy regimen containing an alkylating agent.

It is not established as effective for CLL patients who have never been treated or whose disease is not yet refractory (not responding to treatment). Your doctor will determine whether this treatment is appropriate based on your treatment history.

See full Fludarabine Injection drug information
Keep checking

Other Drugs & Hordenine

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

0Major
180Moderate
149Minor
2,500No known interaction
180 Moderate 149 Minor 2,500 No interaction
Moderate

180 interactions

Showing 60 of 180 moderate interactions — see all 180 on the Hordenine page.

Minor

149 interactions

Showing 60 of 149 minor interactions — see all 149 on the Hordenine page.

No interaction 2,500 drugs checked — show the list

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

Showing the 60 most looked-up of 2,500 medications checked with no known interaction — see the full Hordenine list.

See the full Hordenine interactions page
See every supplement checked against Fludarabine, ranked by severity
Evidence & sources

Hordenine References

The 3 references that drive our Hordenine 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. Barwell CJ, Basma AN, Lafi MA, Leake LD. Deamination of hordenine by monoamine oxidase and its action on vasa deferentia of the rat. J Pharm Pharmacol 1989;41(6):421-3. PubMed
  2. Nelson BC, Putzbach K, Sharpless KE, Sander LC. Mass spectrometric determination of the predominant adrenergic protoalkaloids in bitter orange (Citrus aurantium). J Agric Food Chem 2007;55(24):9769-75. PubMed
  3. 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 Hordenine and Fludarabine Together: Common Questions

Is it safe to take Hordenine with Fludarabine?
We do not list a known interaction between Hordenine and Fludarabine. 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.
Do Hordenine and Fludarabine have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Hordenine and Fludarabine combination checked?
Interactions in our licensed database are recorded against drug classes. Fludarabine is filed under 1 classification, and Hordenine has documented interactions with 3 drug classes — none of Fludarabine'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 Hordenine interact with any other medications?
Yes. Hordenine has 329 documented drug interactions in our database — Fludarabine 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 Fludarabine interact with any supplements?
Yes. Fludarabine has documented interactions with 17 supplements in our database — Hordenine is not one of them. The Fludarabine 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

Hordenine monograph Uses, safety profile, and every drug interaction in one place Fludarabine Injection drug information The full plain-English guide to this medication Fludarabine supplement interactions Every supplement checked against Fludarabine, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Fludarabine and Hordenine?

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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.