Drug & supplement interaction

Cascara Sagrada + Armodafinil

Armodafinil brand name: Nuvigil.

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

Armodafinil falls into 2 drug categories that Cascara Sagrada can interact with; the most serious is rated moderate. Theoretically, cascara sagrada might have additive adverse effects when taken with stimulant laxatives.

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

Cascara Sagrada and Armodafinil

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

Why Are There 2 Interactions?

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

Moderate

STIMULANT LAXATIVES

1 of 2

Why this applies to Armodafinil

Armodafinil falls under STIMULANT LAXATIVES — the group Cascara Sagrada interacts with.

Theoretically, cascara sagrada might have additive adverse effects when taken with stimulant laxatives.
Cascara sagrada has stimulant laxative effects and might compound fluid and electrolyte losses when taken with stimulant laxatives.
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 to know: the interaction on file actually treats armodafinil (Nuvigil) as if it were a stimulant laxative, which it isn't. Armodafinil is a wakefulness medicine for sleepiness, not something that affects your bowels. So the classic concern listed here, two stimulant laxatives stacking up and causing extra fluid and electrolyte loss, doesn't really apply the way the database suggests.

That said, both can be hard on your body in their own ways. Cascara can cause cramping, diarrhea, and dehydration, while armodafinil can already bring on a racing heart, jitteriness, or trouble sleeping. Losing fluids and electrolytes from cascara could make those armodafinil side effects feel worse. This is a theoretical, low-evidence concern, so don't panic, but please check with your pharmacist or doctor before pairing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

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

Theoretically, cascara sagrada might decrease the effects of CYP3A4 substrates.
In vitro research suggests that cascara sagrada can induce CYP3A4 enzymes, albeit to a much lower degree than rifampin, a known CYP3A4 inducer.
Severity Minor 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: your body relies on a liver enzyme called CYP3A4 to help clear armodafinil (Nuvigil). Cascara sagrada has shown, in lab dish studies only, a mild ability to speed up that same enzyme. If that effect carried over into people, it could in theory clear armodafinil a bit faster, meaning it might not keep you as awake and alert as usual.

Honestly, I wouldn't lose sleep over this one. The evidence is weak (test-tube data, not real patients), the cascara effect is far weaker than known enzyme boosters, and it's rated a minor interaction. The bigger practical issue is that cascara is a strong laxative that can throw off your fluids and electrolytes. If you're using both, just check in with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Mazzari ALDA, Lacerda MG, Milton FA, et al. In vitro effects of European and Latin-American medicinal plants in CYP3A4 gene expression, glutathione levels, and P-glycoprotein activity. Front Pharmacol 2022;13:826395. 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

Cascara Sagrada Also Interacts With Other Medications

Cascara Sagrada has 121 moderate, 623 minor known drug interactions in our database — the Armodafinil one above is among them. If you take anything else, check it against the full list below.

Moderate 121 Minor 623 No known interaction 2,086 (incl. Armodafinil)
Taking anything else?

Check Another of Your Medications Against Cascara Sagrada

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

Everything else you take

See Every Supplement That Interacts With Armodafinil

This page covers Cascara Sagrada only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Armodafinil page lists 223 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Grapefruit (major), Jalap (major) and Oleander (major).

By severity: 9 major · 176 moderate · 38 minor.

From our pharmacist’s overview on the Armodafinil page

“Armodafinil (Nuvigil) is a wakefulness drug that works like a stimulant, and the supplements that matter most here do the same thing. Nine of the 223 ingredients on file rate major, and this list warrants real care, starting with those nine.”

Reviewed by 2 · Jul 18, 2026

Open the Armodafinil interaction page

One more smart check

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

We hold 849 real supplement products containing Cascara Sagrada, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cascara Sagrada. Your product may carry other ingredients that interact with Armodafinil too, on top of Cascara Sagrada — 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 Cascara Sagrada and Armodafinil 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 Cascara Sagrada
Top 25%

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

29 days ago today
Medication Armodafinil
Top 25%

#669 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 Cascara Sagrada

What is Cascara Sagrada?

Cascara Sagrada
  • Constipation
  • Bowel cleansing before procedures
  • Hemorrhoids
  • Traditional liver and gallbladder remedy

Cascara sagrada is a stimulant laxative made from the aged bark of a Pacific Northwest tree, used mainly for short-term relief of constipation. Because it can cause cramping, dehydration, and electrolyte problems—and was removed from over-the-counter laxative products in the U.S. due to safety concerns—it should only be used briefly, if at all, and with guidance from a pharmacist or doctor.

Read the full Cascara Sagrada monograph & all interactions
Medication

About Armodafinil

What Is Armodafinil Used For?

Brand name: Nuvigil

Armodafinil tablets (including the brand Nuvigil) are used to improve wakefulness in adults who have excessive sleepiness linked to one of three conditions: obstructive sleep apnea (OSA), narcolepsy, or shift work disorder (SWD).

In obstructive sleep apnea, armodafinil treats the sleepiness itself — not the underlying airway obstruction. If CPAP (a breathing device worn during sleep) is the right treatment for you, your doctor should try that first before adding armodafinil for sleepiness.

See full Armodafinil drug information
Keep checking

Other Drugs & Cascara Sagrada

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

0Major
121Moderate
623Minor
2,085No known interaction
121 Moderate 623 Minor 2,085 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Cascara Sagrada page.

Minor

623 interactions

Showing 60 of 623 minor interactions — see all 623 on the Cascara Sagrada page.

No interaction 2,085 drugs checked — show the list

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

Showing the 60 most looked-up of 2,085 medications checked with no known interaction — see the full Cascara Sagrada list.

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

Can you take Cascara Sagrada with Armodafinil?
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 Cascara Sagrada and Armodafinil?
Armodafinil belongs to more than one drug category, and Cascara Sagrada 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 Cascara Sagrada and Armodafinil 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.