Drug & supplement interaction

Panax Ginseng + Terfenadine

Terfenadine brand name: Seldane.

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

Panax Ginseng has a moderate interaction with Terfenadine. Theoretically, Panax ginseng has an additive effect with drugs that prolong the QT interval and potentially increase the risk of ventricular arrhythmias.

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

Panax Ginseng and Terfenadine

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

Moderate

QT INTERVAL-PROLONGING DRUGS

Why this applies to Terfenadine

Terfenadine falls under QT INTERVAL-PROLONGING DRUGS — the group Panax Ginseng interacts with.

Theoretically, Panax ginseng has an additive effect with drugs that prolong the QT interval and potentially increase the risk of ventricular arrhythmias. However, research is conflicting.
Clinical research shows that short-term use of Panax ginseng can increase the QT interval. However, no changes in QT interval have been identified with prolonged use.
Severity Moderate Likelihood Possible Evidence B

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 concern with pairing Panax ginseng and terfenadine (Seldane). Terfenadine is an older antihistamine that's known for affecting the heart's electrical timing, what we call the QT interval. When that interval gets stretched too far, it can lead to a dangerous abnormal heart rhythm. Some short-term studies suggest ginseng can also nudge the QT interval a bit longer, so taken together they could theoretically add up.

I'll be honest, the evidence here is mixed and mostly theoretical, and longer-term ginseng use didn't show this effect. Still, terfenadine has such a narrow safety margin for the heart that it was actually pulled from the U.S. market. Please loop in your pharmacist or doctor before combining these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Caron MF, Hotsko AL, Robertson S, et al. Electrocardiographic and hemodynamic effects of Panax ginseng. Ann Pharmacother 2002;36:758-63..

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

Panax Ginseng Also Interacts With Other Medications

Panax Ginseng has 1,129 moderate known drug interactions in our database — the Terfenadine one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,129 No known interaction 1,701 (incl. Terfenadine)
Taking anything else?

Check Another of Your Medications Against Panax Ginseng

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

Everything else you take

See Every Supplement That Interacts With Terfenadine

This page covers Panax Ginseng only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Terfenadine page lists 65 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 8 major · 42 moderate · 15 minor.

From our pharmacist’s overview on the Terfenadine page

“Terfenadine (Seldane) is an older antihistamine with a well-known heart rhythm hazard, and its supplement list warrants genuine caution. Eight of the 65 interactions on file are rated major, and the biggest danger is additive strain on the heart's electrical timing: 13 ingredients can prolong the QT interval the way terfenadine itself…”

Reviewed by 2 · Jul 18, 2026

Open the Terfenadine interaction page

One more smart check

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

We hold 517 real supplement products containing Panax Ginseng, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Panax Ginseng. Your product may carry other ingredients that interact with Terfenadine too, on top of Panax Ginseng — 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 Panax Ginseng and Terfenadine 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 Panax Ginseng
Top 25%

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

29 days ago today
Medication Terfenadine
Steady interest

#2,784 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 Panax Ginseng

What is Panax Ginseng?

Panax Ginseng
  • Boosting energy and fighting fatigue
  • Improving mental focus and memory
  • Coping with stress (adaptogen)
  • Erectile dysfunction
  • Supporting immune health
  • Blood sugar support

Panax ginseng is a popular traditional herb used to boost energy, ease stress, and support overall wellness, though scientific evidence is mixed and mostly preliminary. It is generally well tolerated for short-term use in healthy adults, but it can cause side effects like trouble sleeping and may not be safe during pregnancy or breastfeeding. Always check with your pharmacist or doctor before starting it, especially if you have a medical condition or take other medicines.

Read the full Panax Ginseng monograph & all interactions
Keep checking

Other Drugs & Panax Ginseng

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

0Major
1,129Moderate
0Minor
1,700No known interaction
1,129 Moderate 1,700 No interaction
Moderate

1,129 interactions

Showing 60 of 1,129 moderate interactions — see all 1,129 on the Panax Ginseng page.

No interaction 1,700 drugs checked — show the list

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

Showing the 60 most looked-up of 1,700 medications checked with no known interaction — see the full Panax Ginseng list.

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

Can you take Panax Ginseng with Terfenadine?
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 Panax Ginseng and Terfenadine 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 Terfenadine and Panax Ginseng?

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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.