Drug & supplement interaction

Phenpromethamine + Alfentanil

Alfentanil brand name: Alfenta.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Phenpromethamine and Alfentanil 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

Phenpromethamine and Alfentanil

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 Alfentanil and Phenpromethamine 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.

Phenpromethamine safety at a glance

Phenpromethamine overall Avoid This is an unapproved synthetic stimulant that should not be used as a supplement.
Pregnancy Possibly Unsafe When used orally. Certain stimulants, especially when used in combination with other stimulants or intensive exercise, have been associated with cardiovascular... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. Certain stimulants, especially when used in combination with other stimulants or intensive exercise, have been associated with cardiovascular... 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 Alfentanil and Phenpromethamine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Alfentanil

Interactions in our licensed database are recorded against drug classes, not just single drug names. Alfentanil is filed under 6 classifications — including anesthesia, narcotic drugs, cns depressants. Phenpromethamine has documented interactions with 1 drug class — the most serious being stimulant drugs (moderate) — and none of Alfentanil’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

Phenpromethamine Does Interact With Other Medications

Phenpromethamine has 172 moderate known drug interactions in our database — Alfentanil isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Phenpromethamine

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

Special populations

Phenpromethamine in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally. Certain stimulants, especially when used in combination with other stimulants or intensive exercise, have been associated with 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

Everything else you take

See Every Supplement That Interacts With Alfentanil

This page covers Phenpromethamine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Alfentanil page lists 202 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Fever Bark (major) and Gamma-hydroxybutyrate (ghb) (major).

By severity: 10 major · 153 moderate · 39 minor.

From our pharmacist’s overview on the Alfentanil page

“Alfentanil (Alfenta) is a potent, fast-acting opioid, usually given during surgery, and that potency is why this page deserves genuine care rather than a passing glance. Ten of the 202 ingredients listed are rated major, and they cluster into two problems: extra sedation stacked on a drug that already suppresses breathing, and changes…”

Reviewed by 2 · Jul 18, 2026

Open the Alfentanil interaction page

How much people look this up

Where Phenpromethamine and Alfentanil 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 Phenpromethamine
Steady interest

#1,133 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Alfentanil
Top half

#1,021 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 Phenpromethamine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Phenpromethamine and Alfentanil records this page draws on were last updated June 22, 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 Phenpromethamine

What is Phenpromethamine?

  • Nasal decongestion (historical)
  • Stimulant effects (misuse)
  • Pre-workout 'energy' (illegally added to some products)

Phenpromethamine is a synthetic stimulant drug, not a herb or legitimate dietary supplement. It has been found illegally added to some sports and weight-loss supplements, and it is not approved for use in the United States. You should avoid any product that lists it as an ingredient and talk to a pharmacist or doctor.

Not applicable; phenpromethamine is a synthetic chemical, not a plant part · Historically found as a nasal inhaler; not a legitimate dietary supplement ingredient

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

Phenpromethamine: dosing

There is no established or recommended dose of phenpromethamine for supplement use. It is not an approved supplement ingredient, and any amount found in products is unregulated and potentially unsafe.Because the amount in spiked products is unknown and uncontrolled, no dose can be considered safe. The best advice is to avoid products that contain it entirely.

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

Read the full Phenpromethamine monograph & all interactions
Keep checking

Other Drugs & Phenpromethamine

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

0Major
172Moderate
0Minor
2,657No known interaction
Moderate

172 interactions

Showing 60 of 172 moderate interactions — see all 172 on the Phenpromethamine page.

No interaction 2,657 drugs checked — show the list
Evidence & sources

Phenpromethamine References

The 2 references that drive our Phenpromethamine 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

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 Phenpromethamine and Alfentanil Together: Common Questions

Is it safe to take Phenpromethamine with Alfentanil?
We do not list a known interaction between Phenpromethamine and Alfentanil. 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 Phenpromethamine and Alfentanil combination checked?
Interactions in our licensed database are recorded against drug classes. Alfentanil is filed under 6 classifications, and Phenpromethamine has documented interactions with 1 drug class — none of Alfentanil'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 Phenpromethamine interact with any other medications?
Yes. Phenpromethamine has 172 documented drug interactions in our database — Alfentanil 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 Alfentanil interact with any supplements?
Yes. Alfentanil has documented interactions with 202 supplements in our database — Phenpromethamine is not one of them. The Alfentanil interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Alfentanil and Phenpromethamine?

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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.