Drug & supplement interaction

Terminalia + Donepezil

Donepezil brand name: Aricept.

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

Donepezil falls into 2 drug categories that Terminalia can interact with; the most serious is rated moderate. Theoretically, use of Terminalia arjuna may increase the levels and clinical effects of CYP2D6 substrates.

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

Terminalia and Donepezil

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

Why Are There 2 Interactions?

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

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 2

Why this applies to Donepezil

Donepezil falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Terminalia interacts with.

Theoretically, use of Terminalia arjuna may increase the levels and clinical effects of CYP2D6 substrates.
In vitro research shows that Terminalia arjuna extract inhibits CYP2D6 enzymes and reduces CYP2D6 substrate metabolism.
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 gist for donepezil: your liver uses an enzyme called CYP2D6 (along with another one) to help break it down and clear it out. Lab studies suggest Terminalia arjuna may slow that enzyme down. In theory, that could let donepezil build up a bit more than usual, which might mean stronger effects and a higher chance of its typical side effects, things like nausea, diarrhea, loss of appetite, dizziness, a slow heartbeat, or trouble sleeping.

I want to be honest about the strength of this, though. It comes only from test-tube research, not from people, so it's more of a theoretical caution than a proven problem. If you're considering Terminalia while taking donepezil, please run it by your pharmacist or doctor first, especially since both can affect the heart.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Varghese A, Savai J, Pandita N, Gaud RS. In vitro modulatory effects of Terminalia arjuna, arjunic acid, arjunetin, and arjungenin on CYP3A4, CYP2D6, and CYP2C9 enzyme activity in human liver microsomes. Toxicology Reports. 2015(2):806-16. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Donepezil also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, use of Terminalia arjuna may increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that Terminalia arjuna extract inhibits CYP3A4 enzymes and reduces CYP3A4 substrate metabolism.
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 gist for these two together. Your body relies on a liver enzyme called CYP3A4 to help break down and clear donepezil. Lab studies suggest that Terminalia arjuna may slow that same enzyme down. If that happens in real life, donepezil could hang around longer and build up a bit, which can mean stronger cholinergic side effects like nausea, diarrhea, stomach cramps, a slower heart rate, dizziness, trouble sleeping, or muscle cramps.

I want to be honest about how thin the evidence is, though. This concern comes only from test-tube research, not from people, so it's more theoretical than proven. Still, if you'd like to try Terminalia, run it by your pharmacist or doctor first and don't change your donepezil on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Varghese A, Savai J, Pandita N, Gaud RS. In vitro modulatory effects of Terminalia arjuna, arjunic acid, arjunetin, and arjungenin on CYP3A4, CYP2D6, and CYP2C9 enzyme activity in human liver microsomes. Toxicology Reports. 2015(2):806-16. 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

Terminalia Also Interacts With Other Medications

Terminalia has 932 moderate known drug interactions in our database — the Donepezil one above is among them. If you take anything else, check it against the full list below.

Moderate 932 No known interaction 1,898 (incl. Donepezil)
Taking anything else?

Check Another of Your Medications Against Terminalia

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

From our Q&A

Questions About Terminalia or Donepezil

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

This page covers Terminalia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Donepezil page lists 173 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), 1,3-dmaa (moderate) and Acacia Rigidula (moderate).

By severity: 3 major · 127 moderate · 43 minor.

From our pharmacist’s overview on the Donepezil page

“If you or a loved one takes donepezil (Aricept) for Alzheimer's disease, this is a list worth reading with real care, starting with the three major-rated entries: grapefruit, St. John's wort, and activated charcoal.”

Reviewed by 2 · Jul 18, 2026

Open the Donepezil interaction page

One more smart check

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

We hold 306 real supplement products containing Terminalia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Terminalia. Your product may carry other ingredients that interact with Donepezil too, on top of Terminalia — 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 Terminalia and Donepezil 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 Terminalia
Top 25%

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

29 days ago today
Medication Donepezil
Steady interest

#1,588 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 Terminalia

What is Terminalia?

Terminalia
  • Heart health and circulation
  • Digestive problems (constipation, diarrhea)
  • Cholesterol support
  • Antioxidant and anti-inflammatory support
  • Immune support

Terminalia is a group of traditional Ayurvedic tree species (most notably Terminalia arjuna) used for heart, digestive, and general wellness purposes. Some small studies suggest possible benefits for heart and cholesterol health, but the evidence is limited and not strong enough to recommend it as a treatment. Talk to your pharmacist or doctor before using it, especially if you have a heart condition.

Read the full Terminalia monograph & all interactions
Medication

About Donepezil

What Is Donepezil Used For?

Brand name: Aricept

Donepezil is used to treat dementia of the Alzheimer's type. It has been shown to be effective across all stages — mild, moderate, and severe Alzheimer's disease.

It can help with memory, thinking, and daily functioning, though it works differently for each person. Donepezil does not cure Alzheimer's disease or stop the disease from progressing.

See full Donepezil drug information
Keep checking

Other Drugs & Terminalia

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

0Major
932Moderate
0Minor
1,897No known interaction
932 Moderate 1,897 No interaction
Moderate

932 interactions

Showing 60 of 932 moderate interactions — see all 932 on the Terminalia page.

No interaction 1,897 drugs checked — show the list

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

Showing the 60 most looked-up of 1,897 medications checked with no known interaction — see the full Terminalia list.

See the full Terminalia interactions page
See every supplement checked against Donepezil, 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
Terminalia monograph › Uses, safety, and every drug interaction in one place Donepezil supplement interactions › Every supplement checked against Donepezil, ranked by severity Donepezil 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 Terminalia and Donepezil Together: Common Questions

Can you take Terminalia with Donepezil?
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 Terminalia and Donepezil?
Donepezil belongs to more than one drug category, and Terminalia 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 Terminalia and Donepezil 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 Donepezil and Terminalia?

Our pharmacists answer your medication & supplement questions — free.

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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.