Drug & supplement interaction

Hordenine + Lofepramine

Lofepramine brand names: Feprapax, Lomont, Gamanil, Tymelyt.

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

Hordenine has a minor interaction with Lofepramine. Hordenine weakly inhibits cytochrome P450 2D6 (CYP2D6) enzymes in vitro.

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

Hordenine and Lofepramine

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

Minor

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

Why this applies to Lofepramine

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

Hordenine weakly inhibits cytochrome P450 2D6 (CYP2D6) enzymes in vitro. Theoretically, hordenine might increase the levels of CYP2D6 substrates.
Some of drugs that are CYP2D6 substrates include amitriptyline (Elavil), clozapine (Clozaril), codeine, desipramine (Norpramin), donepezil (Aricept), fentanyl (Duragesic), flecainide (Tambocor), fluoxetine (Prozac), meperidine (Demerol), methadone (Dolophine), metoprolol (Lopressor, Toprol XL), olanzapine (Zyprexa), ondansetron (Zofran), tramadol (Ultram), trazodone (Desyrel), and others.
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 for Lofepramine: your liver uses an enzyme called CYP2D6 to help clear this antidepressant out of your system. Hordenine has been shown, in test-tube studies only, to mildly block that same enzyme. So the theory is that hordenine could slow the breakdown of lofepramine and let a bit more of it linger in your blood.

If that happened, you might notice more of lofepramine's usual side effects, like dry mouth, constipation, blurred vision, drowsiness, or a faster heartbeat. That said, the evidence here is weak (lab and animal data, rated minor), so I wouldn't lose sleep over it. Still, since this drug affects your heart and mood, it's worth a quick chat with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. 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

Hordenine Also Interacts With Other Medications

Hordenine has 180 moderate, 148 minor known drug interactions in our database — the Lofepramine one above is one of them. If you take anything else, check it against the full list below.

Moderate 180 Minor 148 No known interaction 2,502 (incl. Lofepramine)
Taking anything else?

Check Another of Your Medications Against Hordenine

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

Everything else you take

See Every Supplement That Interacts With Lofepramine

This page covers Hordenine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lofepramine page lists 244 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), American Hellebore (major), Arsenic (major) and Beer (major).

By severity: 15 major · 190 moderate · 39 minor.

Open the Lofepramine interaction page

One more smart check

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

We hold 339 real supplement products containing Hordenine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Hordenine. Your product may carry other ingredients that interact with Lofepramine too, on top of Hordenine — 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 Hordenine and Lofepramine 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 Hordenine
Top 25%

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

29 days ago today
Medication Lofepramine
Steady interest

#1,997 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 Hordenine

What is Hordenine?

Hordenine
  • Energy and stimulation
  • Athletic and workout performance
  • Weight loss/fat burning
  • Focus and mood
  • Appetite control

Hordenine is a natural alkaloid found in barley and some cacti that is marketed as a stimulant for energy, focus, and fat loss, but solid human evidence for these benefits is lacking. Its safety in people has not been well studied, so caution is warranted, and it should be avoided in pregnancy, breastfeeding, and by people with heart conditions.

Read the full Hordenine monograph & all interactions
Keep checking

Other Drugs & Hordenine

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

0Major
180Moderate
148Minor
2,501No known interaction
180 Moderate 148 Minor 2,501 No interaction
Moderate

180 interactions

Showing 60 of 180 moderate interactions — see all 180 on the Hordenine page.

Minor

148 interactions

Showing 60 of 148 minor interactions — see all 148 on the Hordenine page.

No interaction 2,501 drugs checked — show the list

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

Showing the 60 most looked-up of 2,501 medications checked with no known interaction — see the full Hordenine list.

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

Can you take Hordenine with Lofepramine?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Hordenine and Lofepramine interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Lofepramine and Hordenine?

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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.