Drug & supplement interaction

Isopropylnorsynephrine + Silodosin

Silodosin brand name: Rapaflo.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Isopropylnorsynephrine and Silodosin 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 label for Silodosin states a food rule worth keeping to.

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Interaction report

Isopropylnorsynephrine and Silodosin

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 Silodosin and Isopropylnorsynephrine 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.

Isopropylnorsynephrine safety at a glance

Isopropylnorsyneph... overall Use caution It is a poorly studied synthetic stimulant with unknown long-term safety in humans.
Pregnancy Possibly Unsafe When used orally. Isopropylnorsynephrine has been associated with vomiting, hypertension, blurred vision, palpitations, and respiratory distress. When used in c... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. Isopropylnorsynephrine has been associated with vomiting, hypertension, blurred vision, palpitations, and respiratory distress. When used in c... 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 Silodosin and Isopropylnorsynephrine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Silodosin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Silodosin is filed under 4 classifications — including alpha-adrenergic antagonists, p-glycoprotein substrates, cytochrome p450 3a4 (cyp3a4) substrates. Isopropylnorsynephrine has documented interactions with 2 drug classes — the most serious being antihypertensive drugs (moderate) and stimulant drugs (moderate) — and none of Silodosin’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

Isopropylnorsynephrine Does Interact With Other Medications

Isopropylnorsynephrine has 344 moderate known drug interactions in our database — Silodosin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 344 No known interaction 2,486 (incl. Silodosin)
Taking anything else?

Check Another of Your Medications Against Isopropylnorsynephrine

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

What to actually watch for

What Isopropylnorsynephrine Itself Has Been Linked To

This is not an interaction — nothing below involves Silodosin. It is the side-effect record for Isopropylnorsynephrine on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Isopropylnorsynephrine, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • Raised blood pressure Worth acting on Additional detail

    “Orally and parenterally, isopropylnorsynephrine is generally regarded as unsafe.

    Serious Adverse Effects (Rare):

    Orally: Hypertension, palpitations, respiratory distress, and vomiting. Stroke and cardiac arrest have been reported when used with other stimulants or intensive exercise.”

    Isopropylnorsynephrine · Natural Medicines adverse-effect record, reported in acute respiratory distress syndrome (ards).

    “Orally, isopropylnorsynephrine has been associated with hypertension and palpitations. When used in combination with stimulants or intensive exercise, isopropylnorsynephrine has been associated with adverse cardiovascular events such as stroke and cardiac arrest.”

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

    2 sources 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
    2. 104949. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA
  • Shortness of breath Worth acting on Additional detail

    “Orally, isopropylnorsynephrine has been associated with respiratory distress.”

    Isopropylnorsynephrine · Natural Medicines adverse-effect record, reported in acute respiratory distress syndrome (ards).

    2 sources 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
    2. 104949. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA
  • A fast or pounding heartbeat Additional detail

    Recorded for Isopropylnorsynephrine in the same Natural Medicines adverse-effect record shown under Raised blood pressure above.

  • Vomiting Additional detail

    “Orally, isopropylnorsynephrine has been associated with vomiting.”

    Isopropylnorsynephrine · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    2 sources 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
    2. 104949. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA

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

Special populations

Isopropylnorsynephrine in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally. Isopropylnorsynephrine has been associated with vomiting, hypertension, blurred vision, palpitations, and respiratory distress. When used in combination with stimulants or intensive exercise, isopropylnorsynephrine has been associated with adverse cardiovascular events such as stroke and cardiac arrest. 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

How to take them

Some Silodosin Products Have a Food Rule — Isopropylnorsynephrine Should Not Break It

At least one FDA label for a product containing Silodosin says to take it with food. If you take Isopropylnorsynephrine on an empty stomach out of habit, keep them separate — and take Silodosin with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Silodosin products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION 8 mg capsules taken orally once daily with a meal.

From the Dosage and Administration section of the FDA label we read for Silodosin — where that label names a specific product, the instruction is that product's. See the Silodosin drug page ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About Isopropylnorsynephrine or Silodosin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Isopropylnorsynephrine or Silodosin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Silodosin

This page covers Isopropylnorsynephrine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Silodosin page lists 145 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 104 moderate · 38 minor.

From our pharmacist’s overview on the Silodosin page

“Grapefruit is the first risk I'd flag for anyone taking silodosin (Rapaflo) for an enlarged prostate. It blocks CYP3A4, the enzyme that clears silodosin, so blood levels rise, and higher levels mean more dizziness, lightheadedness, and fainting when standing.”

Reviewed by 2 · Jul 18, 2026

Open the Silodosin interaction page

One more smart check

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

We hold 48 real supplement products containing Isopropylnorsynephrine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Isopropylnorsynephrine. Even though Isopropylnorsynephrine itself has no known interaction with Silodosin, 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 Isopropylnorsynephrine and Silodosin 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 Isopropylnorsynephrine
Steady interest

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

29 days ago today
Medication Silodosin
Steady interest

#2,628 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 Isopropylnorsynephrine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Isopropylnorsynephrine and Silodosin 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 Isopropylnorsynephrine

What is Isopropylnorsynephrine?

  • Weight loss and fat burning
  • Pre-workout energy and stimulation
  • Topical fat reduction (creams and gels)
  • Appetite suppression
  • Athletic performance

Isopropylnorsynephrine is a synthetic stimulant chemically related to synephrine, marketed mainly in weight-loss and pre-workout supplements. It has very little human safety or effectiveness research, and as a stimulant it may raise heart rate and blood pressure, so caution is strongly advised. Talk with a pharmacist or doctor before using any product that contains it.

Synthetic compound (not a plant part) · Capsules, tablets, powders, and topical gels or creams (often in fat-loss and pre-workout products)

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

Isopropylnorsynephrine: dosing

There is no established or proven safe dose for isopropylnorsynephrine. No official health authority has set a recommended amount, and studies do not provide reliable dosing guidance.If a product contains it, follow the label instructions and do not exceed them.

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

Read the full Isopropylnorsynephrine monograph & all interactions
Medication

About Silodosin

What Is Silodosin Used For?

Brand name: Rapaflo

Silodosin capsules are approved to treat the signs and symptoms of benign prostatic hyperplasia (BPH) — the non-cancerous enlargement of the prostate that can make urination difficult, weak, or frequent. It helps ease those urinary symptoms so urine can flow more freely.

It is important to know that silodosin is not approved for treating high blood pressure, even though it affects certain receptors that can influence blood pressure.

Most-Reported Side Effects for Silodosin

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 156 reports
Fatigue 149 reports
Dizziness 141 reports
Acute kidney injury 139 reports
Anemia 126 reports
See full Silodosin drug information
Keep checking

Other Drugs & Isopropylnorsynephrine

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

0Major
344Moderate
0Minor
2,485No known interaction
344 Moderate 2,485 No interaction
Moderate

344 interactions

Showing 60 of 344 moderate interactions — see all 344 on the Isopropylnorsynephrine page.

No interaction 2,485 drugs checked — show the list

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

Showing the 60 most looked-up of 2,485 medications checked with no known interaction — see the full Isopropylnorsynephrine list.

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

Isopropylnorsynephrine References

The 3 references that drive our Isopropylnorsynephrine 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. 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
  2. Cohen PA, Travis JC, Vanhee C, Ohana D, Venhuis BJ. Nine prohibited stimulants found in sports and weight loss supplements: deterenol, phenpromethamine (Vonedrine), oxilofrine, octodrine, beta-methylphenylethylamine (BMPEA), 1,3-dimethylamylamine (1,3-DMA
  3. Anderson WG. The sympathomimetic activity of N-isopropyloctopamine in vitro. J Pharmacol Exp Ther 1983;225(3):553-8. DOI

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 Isopropylnorsynephrine and Silodosin Together: Common Questions

Is it safe to take Isopropylnorsynephrine with Silodosin?
We do not list a known interaction between Isopropylnorsynephrine and Silodosin. 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.
Should I take Isopropylnorsynephrine and Silodosin at the same time of day?
At least one FDA label for a product containing Silodosin says to take it with food. If you take Isopropylnorsynephrine on an empty stomach out of habit, keep them separate and take Silodosin with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Silodosin products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Isopropylnorsynephrine and Silodosin combination checked?
Interactions in our licensed database are recorded against drug classes. Silodosin is filed under 4 classifications, and Isopropylnorsynephrine has documented interactions with 2 drug classes — none of Silodosin'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 Isopropylnorsynephrine interact with any other medications?
Yes. Isopropylnorsynephrine has 344 documented drug interactions in our database — Silodosin 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 Silodosin interact with any supplements?
Yes. Silodosin has documented interactions with 145 supplements in our database — Isopropylnorsynephrine is not one of them. The Silodosin 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

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

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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.