Drug & supplement interaction

Ephedra + Acetaminophen, Phenylephrine, Chlorpheniramine

Acetaminophen, Phenylephrine, Chlorpheniramine brand name: Super Cold Tabs.

Major Interaction
Medically reviewed by · Updated September 2026
The bottom line Major

Acetaminophen, Phenylephrine, Chlorpheniramine falls into 3 drug categories that Ephedra can interact with; the most serious is rated major. Theoretically, concomitant use might increase the risk for serious adverse effects.

Read the full interaction report
SeverityMajor
LikelihoodProbable
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Ephedra and Acetaminophen, Phenylephrine, Chlorpheniramine

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Ephedra interacts with whole categories of medication. Acetaminophen, Phenylephrine, Chlorpheniramine falls into 3 of those categories, so it can interact with Ephedra in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Major).

Major

STIMULANT DRUGS

1 of 3

Why this applies to Acetaminophen, Phenylephrine, Chlorpheniramine

Acetaminophen, Phenylephrine, Chlorpheniramine falls under STIMULANT DRUGS — the group Ephedra interacts with.

Theoretically, concomitant use might increase the risk for serious adverse effects.
Drugs with CNS stimulant properties might increase the risk of hypertension and the adverse cardiovascular effects of ephedra.
Severity Major Likelihood Probable Evidence D

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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the key thing with Super Cold Tabs: one of its ingredients, phenylephrine, is itself a stimulant decongestant that tightens blood vessels and can nudge your blood pressure up. Ephedra (which also acts as a powerful stimulant through ephedrine) does the very same thing. Stack the two together and you're essentially doubling up on that stimulant push, which can raise the risk of high blood pressure, a racing or pounding heart, headache, jitteriness, and in serious cases dangerous cardiovascular events.

This concern is based mostly on anecdotal reports rather than strong studies, but the direction is clear and the potential harm is real. On top of that, ephedra is banned in U.S. supplements for safety reasons. Please don't combine these, and check with your pharmacist about safer cold-relief options.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. White LM, Gardner SF, Gurley BJ, et al. Pharmacokinetics and Cardiovascular Effects of Ma-Huang (Ephedra sinica) in Normotensive Adults. J Clin Pharmacol 1997;37:116-22.
  2. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. PubMed
  3. Kernan, W. N., Viscoli, C. M., Brass, L. M., Broderick, J. P., Brott, T., Feldmann, E., Morgenstern, L. B., Wilterdink, J. L., and Horwitz, R. I. Phenylpropanolamine and the risk of hemorrhagic stroke. N.Engl.J Med 12-21-2000;343(25):1826-1832. PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 3

Acetaminophen, Phenylephrine, Chlorpheniramine also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, ephedra might decrease levels of drugs metabolized by CYP1A2.
Some animal research suggests that ephedra induces CYP1A2 and increases the clearance of CYP1A2 substrates such as caffeine.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing about combining ephedra with a cold medicine like Super Cold Tabs: the bigger concern isn't really the enzyme part. On file, the worry is that ephedra might speed up a liver enzyme (CYP1A2) and lower levels of certain drugs, but that's based only on animal and lab data, and none of these three ingredients (acetaminophen, phenylephrine, chlorpheniramine) leans heavily on CYP1A2. So that piece is mostly theoretical and weak.

What I'd actually flag is the stimulant overlap. Ephedra and the phenylephrine in this product both raise blood pressure and heart rate, so stacking them could mean a racing heart, jitteriness, or a dangerous blood pressure spike. Ephedra is banned here for good reason. Please talk with your pharmacist or doctor before mixing these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Tang J, Zhou X, Ji H, Zhu D, Wu L. Effects of ephedra water decoction and cough tablets containing ephedra and liquorice on CYP1A2 and the pharmacokinetics of theophylline in rats. Phytother Res. 2012;26(3):470-4. PubMed
Moderate

HEPATOTOXIC DRUGS

3 of 3

Acetaminophen, Phenylephrine, Chlorpheniramine also falls under HEPATOTOXIC DRUGS.

Theoretically, concomitant use might have additive adverse hepatotoxic effects.
There are numerous cases of liver toxicity from ephedra-containing supplements.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the concern with combining ephedra and a product like Super Cold Tabs. The acetaminophen piece is the part that can stress your liver, especially at higher doses or if you drink alcohol. Ephedra-containing supplements have been tied to cases of liver injury on their own, so the worry is that the two together could add up and put more strain on your liver.

I'll be honest, this particular interaction is mostly theoretical, based on how each affects the liver rather than strong studies. There's a separate point too: both ephedra and the phenylephrine are stimulants, so together they can raise your heart rate and blood pressure. Ephedra isn't sold here for good reason. Please check with your pharmacist before pairing these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Nadir A, Agrawal S, King PD, Marshall JB. Acute hepatitis associated with the use of a Chinese herbal product, ma-huang. Am J Gastroenterol 1996;91:1436-8.
  2. Borum, M. L. Fulminant exacerbation of autoimmune hepatitis after the use of ma huang. Am J Gastroenterol. 2001;96(5):1654-1655. PubMed
  3. Vigano, M., Lampertico, P., and Colombo, M. Acute hepatitis following assumption of a herbal remedy. Eur.J.Gastroenterol.Hepatol. 2008;20(4):364-365. PubMed
  4. Neff, G. W., Reddy, K. R., Durazo, F. A., Meyer, D., Marrero, R., and Kaplowitz, N. Severe hepatotoxicity associated with the use of weight loss diet supplements containing ma huang or usnic acid. J Hepatol. 2004;41(6):1062-1064. PubMed
  5. Bajaj J, Knox JF, Komorowski R, Saeian K. The irony of herbal hepatitis: Ma-Huang-induced hepatotoxicity associated with compound heterozygosity for hereditary hemochromatosis. Dig Dis Sci. 2003;48(10):1925-8.
  6. Charalampopoulos A, Karatsourakis T, Tsiodra P. Acute hepatitis associated with the use of Ma-huang in a young adult. Eur J Intern Med. 2007;18(1):81. PubMed
  7. Skoulidis F, Alexander GJ, Davies SE. Ma huang associated acute liver failure requiring liver transplantation. Eur J Gastroenterol Hepatol. 2005;17(5):581-4. PubMed
  8. Drug record: Ma huang. U.S. National Library of Medicine: Livertox Database. https://livertox.nlm.nih.gov/Ephedra.htm. Updated October 16, 2017. Accessed November 1, 2017.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Ephedra Also Interacts With Other Medications

Ephedra has 336 major, 496 moderate known drug interactions in our database — the Acetaminophen, Phenylephrine, Chlorpheniramine one above is among them. If you take anything else, check it against the full list below.

Major 336 Moderate 496 No known interaction 1,998 (incl. Acetaminophen, Phenylephrine, Chlorpheniramine)
Taking anything else?

Check Another of Your Medications Against Ephedra

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

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Phenylephrine, Chlorpheniramine

This page covers Ephedra only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Phenylephrine, Chlorpheniramine page lists 289 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Grapefruit (major) and Henbane (major).

By severity: 14 major · 229 moderate · 46 minor.

From our pharmacist’s overview on the Acetaminophen, Phenylephrine, Chlorpheniramine page

“Super Cold Tabs earns more caution than a cold remedy usually gets. It combines acetaminophen, the decongestant phenylephrine, and the antihistamine chlorpheniramine, and 14 of the 289 supplements on file interact at a major level, so those are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Phenylephrine, Chlorpheniramine interaction page

One more smart check

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

We hold 37 real supplement products containing Ephedra, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ephedra. Your product may carry other ingredients that interact with Acetaminophen, Phenylephrine, Chlorpheniramine too, on top of Ephedra — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Ephedra and Acetaminophen, Phenylephrine, Chlorpheniramine 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 Ephedra
Top half

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

29 days ago today
Medication Acetaminophen, Phenylephrine, Chlorpheniramine
Top 10%

#280 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.

Supplement

About Ephedra

What is Ephedra?

Ephedra
  • Weight loss
  • Nasal and sinus congestion
  • Asthma and breathing problems
  • Boosting energy and athletic performance
  • Allergies

Ephedra (ma huang) contains powerful stimulants like ephedrine that affect the heart and nervous system. Because it has been linked to serious harms including high blood pressure, stroke, and death, it is banned for use in dietary supplements in the U.S. and many other countries. We do not recommend using ephedra-containing supplements; talk to your pharmacist or doctor about safer, approved options.

Read the full Ephedra monograph & all interactions
Keep checking

Other Drugs & Ephedra

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

336Major
496Moderate
0Minor
1,997No known interaction
336 Major 496 Moderate 1,997 No interaction
Major

336 interactions

Showing 60 of 336 major interactions — see all 336 on the Ephedra page.

Moderate

496 interactions

Showing 60 of 496 moderate interactions — see all 496 on the Ephedra page.

No interaction 1,997 drugs checked — show the list

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

Showing the 60 most looked-up of 1,997 medications checked with no known interaction — see the full Ephedra list.

See the full Ephedra interactions page
See every supplement checked against Acetaminophen, Phenylephrine, Chlorpheniramine, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

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

Keep exploring
Ephedra monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Phenylephrine, Chlorpheniramine supplement interactions › Every supplement checked against Acetaminophen, Phenylephrine, Chlorpheniramine, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Ephedra and Acetaminophen, Phenylephrine, Chlorpheniramine Together: Common Questions

Can you take Ephedra with Acetaminophen, Phenylephrine, Chlorpheniramine?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 3 interactions listed for Ephedra and Acetaminophen, Phenylephrine, Chlorpheniramine?
Acetaminophen, Phenylephrine, Chlorpheniramine belongs to more than one drug category, and Ephedra interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Ephedra and Acetaminophen, Phenylephrine, Chlorpheniramine interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Acetaminophen, Phenylephrine, Chlorpheniramine and Ephedra?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.