Drug & supplement interaction

Cereus + Selegiline

Selegiline brand names: Carbex, Eldepryl, Emsam, Zelapar.

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

Cereus has a moderate interaction with Selegiline. Theoretically, excessive doses of cereus may interact with MAOIs, because of the tyramine content.

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

Cereus and Selegiline

Here is the interaction we found between these two, with the evidence behind it.

Moderate

MONOAMINE OXIDASE INHIBITORS (MAOIs)

Why this applies to Selegiline

Selegiline falls under MONOAMINE OXIDASE INHIBITORS (MAOIs) — the group Cereus interacts with.

Theoretically, excessive doses of cereus may interact with MAOIs, because of the tyramine content.
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 selegiline: it's an MAO inhibitor, and one of the classic cautions with these drugs is something called tyramine. Tyramine is a compound found in certain aged or fermented foods. Normally your body breaks it down quickly, but when an MAOI is on board, tyramine can pile up and push your blood pressure suddenly higher. People sometimes call this a tyramine reaction, and it can show up as a pounding headache, a racing heart, sweating, or a spike in blood pressure.

The concern here is that cereus may contain some tyramine, so very large or concentrated doses could theoretically add to that risk. I'll be honest, this is based on pharmacology theory, not solid human studies, so don't panic. Still, since selegiline already needs careful diet attention, please run any cereus supplement by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.

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

Cereus Also Interacts With Other Medications

Cereus has 9 moderate known drug interactions in our database — the Selegiline one above is one of them. If you take anything else, check it against the full list below.

Moderate 9 No known interaction 2,821 (incl. Selegiline)
Taking anything else?

Check Another of Your Medications Against Cereus

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

Everything else you take

See Every Supplement That Interacts With Selegiline

This page covers Cereus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Selegiline page lists 102 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: 14 major · 75 moderate · 13 minor.

Open the Selegiline interaction page

One more smart check

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

We hold 3 real supplement products containing Cereus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cereus. Your product may carry other ingredients that interact with Selegiline too, on top of Cereus — 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 Cereus and Selegiline 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 Cereus
Steady interest

#1,097 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Selegiline
Steady interest

#2,235 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 Cereus

What is Cereus?

  • Heart palpitations
  • Mild heart symptoms
  • Anxiety and nervous tension
  • Shortness of breath
  • Fluid retention

Cereus (often called night-blooming cereus) is a cactus traditionally used in folk and homeopathic medicine for heart-related complaints like palpitations. High-quality human evidence supporting these uses is lacking, and because it may affect the heart, it should be used only under medical guidance. Pregnant and breastfeeding people should avoid it.

Read the full Cereus monograph & all interactions
Medication

About Selegiline

What Is Selegiline Used For?

Brand names: Carbex, Eldepryl, Emsam, Zelapar

Selegiline is used as an add-on treatment for people with Parkinson's disease who are already taking levodopa/carbidopa but are finding that the medication's effects are wearing off or becoming less reliable. It is not used alone — it only works as part of a combination approach.

In clinical studies, adding selegiline helped reduce the amount of daily levodopa needed, cut down on "off" time (periods when symptoms break through), and improved things like tremor, speech, movement, and overall daily function.

See full Selegiline drug information
Keep checking

Other Drugs & Cereus

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

0Major
9Moderate
0Minor
2,820No known interaction
9 Moderate 2,820 No interaction
Moderate

9 interactions

No interaction 2,820 drugs checked — show the list

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

Showing the 60 most looked-up of 2,820 medications checked with no known interaction — see the full Cereus list.

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

Can you take Cereus with Selegiline?
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.
How serious is the Cereus and Selegiline 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 Selegiline and Cereus?

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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.