Herb & supplement monograph

Phenpromethamine Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated June 2026
What is this page for?

First and foremost: how Phenpromethamine interacts with medications. The heart of this page is the interaction list — every drug Phenpromethamine is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Phenpromethamine is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Phenpromethamine Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Phenpromethamine drug interaction appears low for most people, though anyone taking a stimulant medication should be more careful. None of the listed interactions are rated major, and every one of them rests on theoretical reasoning rather than documented human studies.

Interactions deserving the most attention

The one concern worth knowing about involves stimulant drugs. Phenpromethamine acts like a stimulant itself, so combining it with medications that also stimulate the body could, in theory, add up and put extra strain on the heart and blood pressure. This has not been confirmed in human studies, but because cardiovascular effects can matter, we think this combination deserves respect rather than dismissal.

What the rest of the list means

Although a large number of medications appear on this interaction list, they all trace back to that single stimulant concern, which is theoretical at this point. In other words, the long list reflects how many drugs share stimulant properties, not many separate proven problems. No interaction here has been shown to cause meaningful harm in people so far.

Check your medications against Phenpromethamine

Based on HelloPharmacist’s Phenpromethamine interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Phenpromethamine

172 medications have a known interaction with Phenpromethamine, graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
Acetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine› Acetaminophen, Brompheniramine, PhenylpropanolamineDimetapp Cold and Flu› Acetaminophen, Butalbital, CaffeineEsgic, Esgic Plus, Fiogesic, Fioricet, Repan, Tecnal +1 more› Acetaminophen, Butalbital, Caffeine, CodeineEsgic with Codeine, Fioricet w/ Codeine› Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound› Acetaminophen, Caffeine, CodeineGesic C15, Gesic C30, Gesic C8, Lenoltec 1, Lenoltec 2, Lenoltec 3 +1 more› Acetaminophen, Caffeine, Codeine, SalicylamideCodalan No.1, Codalan No.2, Codalan No.3› Acetaminophen, Caffeine, DihydrocodeineDHC Plus, Panlor DC, Panlor SS› Acetaminophen, Caffeine, IsomethepteneMigralam› Acetaminophen, Caffeine, PyrilamineMidol Max Strength Menstrual› Acetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex› Acetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief› Acetaminophen, Chlorpheniramine, Dextromethorphan, PseudoephedrineChildren's Tylenol Cold Plus Cough, Tylenol Cold Ex Strength› Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, SalicylamideRhinogesic GG› Acetaminophen, Chlorpheniramine, PhenylephrineAlka-Seltzer PLUS, Histex SR, Protid› Acetaminophen, Chlorpheniramine, Phenylephrine, SalicylamideRhinogesic, Rhinogesic JR› Acetaminophen, Chlorpheniramine, PhenylpropanolamineAlumadrine, Conex, Sinadrin Max Strength, Sinulin› Acetaminophen, Chlorpheniramine, Phenylpropanolamine, OpiumHista-Derfule› Acetaminophen, Chlorpheniramine, Phenylpropanolamine, PhenyltoloxamineNorel Plus› Acetaminophen, Chlorpheniramine, PseudoephedrineAlka-Seltzer PLUS Liquid Gels, Children's Tylenol Cold, Codimal, Comtrex, Extra Strength Tylenol Allergy Sinus, Lorsin +3 more› Acetaminophen, Dexbrompheniramine, PseudoephedrineSinadrin Plus› Acetaminophen, Dextromethorphan, Doxylamine, PseudoephedrineVicks NyQuil› Acetaminophen, Dextromethorphan, Guaifenesin, PhenylephrineConar-A› Acetaminophen, Dextromethorphan, Guaifenesin, PhenylpropanolamineAnatuss› Acetaminophen, Dextromethorphan, Guaifenesin, PseudoephedrineRobitussin Cold, Severe Cold, Suphedrine Cold/Cough› Acetaminophen, Dextromethorphan, Phenylpropanolamine, PyrilamineTheracaps› Acetaminophen, Dextromethorphan, PseudoephedrineAlka-Seltzer PLUS Flu Liquid Gels, Non Aspirin Cold Caps, Tylenol Cold, Tylenol Flu Daytime Ex Strength, Tylenol Flu Ex Strength› Acetaminophen, Dichloralantipyrine, IsomethepteneAmidrine, Midchlor, Migquin, Migratine› Acetaminophen, Dichloralphenazone, IsomethepteneMidrin› Acetaminophen, Dichlorophenazone, IsometheptaneIsocom›
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Phenpromethamine combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Phenpromethamine affects

Every type of medication (drug category) Phenpromethamine is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 1 drug category Phenpromethamine interacts with
Stimulant Drugs
Stimulant Drugs

Theoretically, taking phenpromethamine with stimulant drugs might have additive effects and increase the risk of adverse cardiovascular effects.
Phenpromethamine is a sympathomimetic compound with stimulant properties.

Likelihood Possible Evidence D
Monograph

Phenpromethamine: Uses, Safety & Side Effects

Medically reviewed by · Reviewed June 2026 ·
The bottom line

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.

Part used
Not applicable; phenpromethamine is a synthetic chemical, not a plant part
Common forms
Historically found as a nasal inhaler; not a legitimate dietary supplement ingredient
People commonly use it for
  • Nasal decongestion (historical)
  • Stimulant effects (misuse)
  • Pre-workout 'energy' (illegally added to some products)

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallBest avoided

This is an unapproved synthetic stimulant that should not be used as a supplement.

PregnancyPossibly Unsafe

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

Read the full pregnancy detail
BreastfeedingPossibly Unsafe

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

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Phenpromethamine is not a herb or a natural dietary supplement. It is a synthetic (man-made) chemical that belongs to a family of amphetamine-like stimulant compounds. It was originally developed many decades ago and was once used in a nasal inhaler product to help relieve a stuffy nose.

Today, phenpromethamine is not approved as a medicine or as a supplement ingredient in the United States. It has gained attention because public health researchers and the U.S. Food and Drug Administration (FDA) have found it illegally added to some sports, "pre-workout," and weight-loss products sold as supplements. When it shows up in these products, it is there as an undeclared or hidden drug, not as a legitimate ingredient.

Because it is a stimulant that is not regulated as a supplement, we are covering it here mainly so you can recognize the name and stay away from products that contain it.

How it works

Phenpromethamine is chemically related to amphetamine-type stimulants. Drugs in this group generally work by increasing the activity of certain brain chemicals, such as norepinephrine and dopamine, which can raise alertness, heart rate, and blood pressure.

As a decongestant, its stimulant-like action could narrow blood vessels in the nose, which is why it was once used to reduce nasal stuffiness.

It is important to understand that this information comes from what is known about its chemical class, not from large, modern human studies of phenpromethamine itself. The way it behaves in the body has not been well studied with current methods.

Effectiveness

Does Phenpromethamine work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 3 uses evaluated
3 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.

For Phenpromethamine, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 3 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Athletic performance
Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral phenpromethamine for athletic performance, there is insufficient reliable information about the clinical effects of phenpromethamine for this purpose.

Insufficient Reliable Evidence To Rate Exercise-induced muscle damage
Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral phenpromethamine for muscle recovery after exercise, there is insufficient reliable information about the clinical effects of phenpromethamine for this purpose.

Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

Although there is interest in using oral phenpromethamine for weight loss, there is insufficient reliable information about the clinical effects of phenpromethamine for this purpose.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Phenpromethamine should be avoided. It is an unapproved stimulant drug, and its safety as taken in spiked supplements has not been established. Because it acts like other amphetamine-type stimulants, it could raise blood pressure and heart rate and may pose risks to the heart and nervous system.

People with high blood pressure, heart disease, anxiety, thyroid problems, or a history of substance use should be especially careful to avoid any product containing it. Athletes should also be aware that it may be a banned substance in sport and could cause a failed drug test.

Pregnancy and breastfeeding: Avoid phenpromethamine completely. Stimulant drugs can be risky during pregnancy and may pass into breast milk, and there is no safety information to support its use.

If you find phenpromethamine listed on a supplement label, do not use the product, and consider reporting it. Talk with a pharmacist or doctor if you have already taken it and have concerns.

Side effects

Because phenpromethamine acts as a stimulant, possible side effects may include:

  • Faster or irregular heartbeat
  • Increased blood pressure
  • Jitteriness, restlessness, or anxiety
  • Trouble sleeping
  • Headache
  • Nausea

More serious problems are possible with stimulant drugs, especially at higher doses, including dangerous spikes in blood pressure and heart rhythm problems. Because phenpromethamine is unregulated and often hidden in products, you may not know how much you are taking, which increases the risk.

If you experience chest pain, severe headache, a very rapid heartbeat, or fainting after taking a product containing it, seek medical care right away.

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. If you are unsure whether a supplement contains phenpromethamine or another hidden stimulant, ask a pharmacist before taking it.

Pregnancy & Breastfeeding
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

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

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
Keep reading

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.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Pharmacist Counseling Corner

Phenpromethamine: Common Questions

What is Phenpromethamine used for, and does it work?
People use Phenpromethamine for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.
Does Phenpromethamine interact with prescription medications?
Yes. We list 172 medications with a known interaction with Phenpromethamine. Use the checker above to see how Phenpromethamine interacts with a specific drug.
How are Phenpromethamine interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Phenpromethamine with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Phenpromethamine interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
Is Phenpromethamine a natural herb or supplement?
No. Phenpromethamine is a synthetic (man-made) stimulant chemical, not a plant or natural supplement. It has been found illegally added to some sports and weight-loss products.
Is Phenpromethamine safe to take?
It is best avoided. It is an unapproved stimulant drug with no established safety as a supplement, and it may raise heart rate and blood pressure.
Why is Phenpromethamine in some supplements?
It has been illegally and sometimes secretly added to certain pre-workout and weight-loss products to create stimulant effects. This is not a legal or safe use, and the FDA has warned about it.
Can I take Phenpromethamine if I am pregnant or breastfeeding?
No. You should avoid it entirely during pregnancy and breastfeeding, since stimulant drugs can be harmful and there is no safety information to support its use.

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

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