Drug & supplement interaction

Ilex Guayusa + Ephedrine Sulfate

Ephedrine Sulfate brand names: Akovaz, Emerphed.

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

Ephedrine Sulfate falls into 2 drug categories that Ilex Guayusa can interact with; the most serious is rated moderate. Theoretically, concomitant use might increase stimulant adverse effects.

Read the full interaction report
SeverityModerate
LikelihoodProbable
Interactions2
EvidenceC
What do Severity, Likelihood & Evidence mean?
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Interaction report

Ilex Guayusa and Ephedrine Sulfate

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Ilex Guayusa interacts with whole categories of medication. Ephedrine Sulfate falls into 2 of those categories, so it can interact with Ilex Guayusa in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

STIMULANT DRUGS

1 of 2

Why this applies to Ephedrine Sulfate

Ephedrine Sulfate falls under STIMULANT DRUGS — the group Ilex Guayusa interacts with.

Theoretically, concomitant use might increase stimulant adverse effects.
Ilex guayusa contains caffeine. Due to the central nervous system (CNS) stimulant effects of caffeine, concomitant use with stimulant drugs can increase the risk of adverse effects.
Severity Moderate Likelihood Probable Evidence C

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 simple version: guayusa is basically a caffeine-rich tea, and ephedrine is already a strong stimulant. When you stack two stimulants, their effects can pile on top of each other. With ephedrine, that means you may notice a faster or pounding heartbeat, jitteriness, anxiety, trouble sleeping, or a bump in blood pressure. Guayusa isn't activating or deactivating the drug, it's just adding more stimulation on its own.

Keep in mind this concern is based on expert opinion rather than hard studies, so it's not a guaranteed problem. Still, a regular cup of guayusa can add up, especially alongside other caffeine. If you take ephedrine and want to enjoy guayusa, it's worth a quick chat with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html. DOI
Moderate

BETA-ADRENERGIC AGONISTS

2 of 2

Ephedrine Sulfate also falls under BETA-ADRENERGIC AGONISTS.

Theoretically, concomitant use of large amounts of Ilex guayusa might increase cardiac inotropic effects of beta-agonists.
Ilex guayusa contains caffeine. Caffeine can increase cardiac inotropic effects of beta-agonists.
Severity Moderate 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 simple version: guayusa is basically a caffeine drink, similar to yerba mate or green tea. Ephedrine is already a stimulant that revs up your heart and can make it pump harder. Stacking caffeine on top of it may add to that push, so the two together could lead to a faster or more forceful heartbeat, palpitations, jitteriness, higher blood pressure, or trouble sleeping.

I want to be honest about the evidence here. This concern is theoretical, based on how both stimulants work rather than strong human studies, and it mainly applies to large, concentrated amounts of guayusa rather than an occasional cup. Still, since both affect the heart, it's worth a quick chat with your pharmacist or doctor before combining them, especially if you have any heart or blood pressure issues.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.

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

Ilex Guayusa Also Interacts With Other Medications

Ilex Guayusa has 8 major, 469 moderate, 127 minor known drug interactions in our database — the Ephedrine Sulfate one above is among them. If you take anything else, check it against the full list below.

Major 8 Moderate 469 Minor 127 No known interaction 2,226 (incl. Ephedrine Sulfate)
Taking anything else?

Check Another of Your Medications Against Ilex Guayusa

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

Everything else you take

See Every Supplement That Interacts With Ephedrine Sulfate

This page covers Ilex Guayusa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ephedrine Sulfate page lists 46 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Ephedra (major), Peyote (major), Rauvolfia Vomitoria (major), Sida Cordifolia (major) and 1,3-dmaa (moderate).

By severity: 4 major · 38 moderate · 4 minor.

Open the Ephedrine Sulfate interaction page

How much people look this up

Where Ilex Guayusa and Ephedrine Sulfate 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 Ilex Guayusa
Steady interest

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

29 days ago today
Medication Ephedrine Sulfate
Steady interest

#1,805 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 Ilex Guayusa

What is Ilex Guayusa?

  • Energy and alertness
  • Mental focus
  • Antioxidant support
  • Appetite control
  • Athletic and physical performance

Ilex guayusa is a caffeine-containing holly leaf from the Amazon, traditionally brewed as a tea for energy and alertness, much like yerba mate or green tea. There is limited human research confirming specific health benefits, and its main reliable effect comes from its caffeine content. Because it is a stimulant, use it cautiously and check with your pharmacist or doctor if you have heart concerns or are pregnant.

Read the full Ilex Guayusa monograph & all interactions
Keep checking

Other Drugs & Ilex Guayusa

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

8Major
469Moderate
127Minor
2,225No known interaction
8 Major 469 Moderate 127 Minor 2,225 No interaction
Major

8 interactions

Moderate

469 interactions

Showing 60 of 469 moderate interactions — see all 469 on the Ilex Guayusa page.

Minor

127 interactions

Showing 60 of 127 minor interactions — see all 127 on the Ilex Guayusa page.

No interaction 2,225 drugs checked — show the list

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

Showing the 60 most looked-up of 2,225 medications checked with no known interaction — see the full Ilex Guayusa list.

See the full Ilex Guayusa interactions page
See every supplement checked against Ephedrine Sulfate, 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
Ilex Guayusa monograph › Uses, safety, and every drug interaction in one place Ephedrine Sulfate supplement interactions › Every supplement checked against Ephedrine Sulfate, 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 Ilex Guayusa and Ephedrine Sulfate Together: Common Questions

Can you take Ilex Guayusa with Ephedrine Sulfate?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Ilex Guayusa and Ephedrine Sulfate?
Ephedrine Sulfate belongs to more than one drug category, and Ilex Guayusa 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 Ilex Guayusa and Ephedrine Sulfate interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

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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.