Drug & supplement interaction

Ilex Guayusa + Amphetamine

Amphetamine brand names: Dyanavel XR, Adensys XR-ODT, Mydayis, Adzenys ER.

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

Amphetamine 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 Amphetamine

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. Amphetamine 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 Amphetamine

Amphetamine 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 drink, and amphetamine is already a strong stimulant for your brain and body. When you stack two stimulants together, their effects can add up. This isn't a case of one blocking the other's breakdown, it's just two things pushing in the same direction.

In practice, that could mean a faster or pounding heartbeat, higher blood pressure, jitteriness, trouble sleeping, or feeling anxious and on edge. The good news is this is rated as a moderate, theory-based concern, and an occasional cup of guayusa tea may not cause trouble for everyone. Still, if you notice your heart racing or you can't settle down, that's worth mentioning. Check with your pharmacist or doctor before pairing the two regularly.

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

MONOAMINE OXIDASE INHIBITORS (MAOIs)

2 of 2

Amphetamine also falls under MONOAMINE OXIDASE INHIBITORS (MAOIs).

Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Ilex guayusa can contain caffeine. Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies. Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis.
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 pairing guayusa tea with your amphetamine: both are stimulants. Amphetamine already pushes your body to release more norepinephrine and dopamine, which is what raises focus but can also bump up heart rate and blood pressure. Add the caffeine from guayusa on top, and you may notice more jitteriness, a racing or pounding heart, trouble sleeping, and higher blood pressure.

The specific concern on file (caffeine mildly blocking the MAO enzyme, which could push blood pressure up) is theoretical and based on lab studies, not strong human evidence, so I wouldn't panic. A normal cup or two is different from concentrated caffeine pills. Still, if you have any heart or blood pressure issues, check with your pharmacist or doctor before combining them.

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.
  2. MacKenzie, T., Comi, R., Sluss, P., Keisari, R., Manwar, S., Kim, J., Larson, R., and Baron, J. A. Metabolic and hormonal effects of caffeine: randomized, double-blind, placebo-controlled crossover trial. Metabolism 2007;56(12):1694-1698. PubMed
  3. Moisey, L. L., Robinson, L. E., and Graham, T. E. Consumption of caffeinated coffee and a high carbohydrate meal affects postprandial metabolism of a subsequent oral glucose tolerance test in young, healthy males. Br.J Nutr. 2010;103(6):833-841. PubMed
  4. Buscemi, S., Verga, S., Batsis, J. A., Donatelli, M., Tranchina, M. R., Belmonte, S., Mattina, A., Re, A., and Cerasola, G. Acute effects of coffee on endothelial function in healthy subjects. Eur.J Clin Nutr. 2010;64(5):483-489. PubMed
  5. Orozco-Gregorio, H., Mota-Rojas, D., Bonilla-Jaime, H., Trujillo-Ortega, M. E., Becerril-Herrera, M., Hernandez-Gonzalez, R., and Villanueva-Garcia, D. Effects of administration of caffeine on metabolic variables in neonatal pigs with peripartum asphyxia PubMed

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 Amphetamine 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. Amphetamine)
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.

From our Q&A

Questions About Ilex Guayusa or Amphetamine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Ilex Guayusa or Amphetamine, 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 Amphetamine

This page covers Ilex Guayusa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Amphetamine page lists 130 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Bitter Orange (major), Brewer's Yeast (major) and Cowhage (major).

By severity: 16 major · 97 moderate · 17 minor.

From our pharmacist’s overview on the Amphetamine page

“Amphetamine (Dyanavel XR, Adzenys ER, Mydayis) is a prescription stimulant, usually taken for ADHD, and its interaction list is one to approach with genuine care. Of the 130 supplements and herbal ingredients on file, 16 carry a major rating, and many of those work the same way, either inhibiting monoamine oxidase, as yohimbe does, or…”

Reviewed by 2 · Jul 18, 2026

Open the Amphetamine interaction page

How much people look this up

Where Ilex Guayusa and Amphetamine 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

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

29 days ago today
Medication Amphetamine
Top 5%

#42 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
Medication

About Amphetamine

What Is Amphetamine Used For?

Brand names: Dyanavel XR, Adensys XR-ODT, Mydayis, Adzenys ER

Amphetamine treats Attention Deficit Hyperactivity Disorder (ADHD) in patients 6 years and older. Adzenys XR-ODT, Dyanavel XR, and the amphetamine extended-release orally disintegrating tablet formulations are specifically approved for ADHD in this age group.

Amphetamine Sulfate tablets and Evekeo (amphetamine sulfate tablets) are also approved for narcolepsy (a sleep disorder causing uncontrollable daytime sleepiness) and as a short-term aid in a calorie-restricted weight-loss program for exogenous obesity (weight gain from external factors like overeating) in patients who have not responded to other approaches.

See full Amphetamine drug information
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 Amphetamine, 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 Amphetamine supplement interactions › Every supplement checked against Amphetamine, ranked by severity Amphetamine drug information › The full plain-English guide to this medication 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 Amphetamine Together: Common Questions

Can you take Ilex Guayusa with Amphetamine?
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 Amphetamine?
Amphetamine 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 Amphetamine 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

Still Have a Question About Amphetamine and Ilex Guayusa?

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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.