Drug & supplement interaction

Licorice + Treprostinil

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

Treprostinil falls into 2 drug categories that Licorice can interact with; the most serious is rated moderate. Theoretically, licorice might reduce the effects of antihypertensive drugs.

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

Licorice and Treprostinil

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

Why Are There 2 Interactions?

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

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 2

Why this applies to Treprostinil

Treprostinil falls under ANTIHYPERTENSIVE DRUGS — the group Licorice interacts with.

Theoretically, licorice might reduce the effects of antihypertensive drugs.
In human research, licorice increases blood pressure in a dose-dependent manner.
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 thing to know about treprostinil (Orenitram): it's used to treat pulmonary arterial hypertension, meaning it works by relaxing and widening blood vessels to ease the pressure your heart is fighting against. Licorice, when it contains glycyrrhizin, can do the opposite. Taken in large amounts or over a long stretch, it makes your body hold onto sodium and water and lose potassium, which tends to raise blood pressure.

So the worry is that licorice could work against what treprostinil is trying to do. This is more of a theoretical, dose-related concern than a guaranteed clash, and occasional culinary amounts likely won't matter. Deglycyrrhizinated (DGL) licorice avoids this issue entirely. Before adding any licorice supplement, please check with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sigurjonsdottir HA, Ragnarsson J, Franzson L, Sigurdsson G. Is blood pressure commonly raised by moderate consumption of liquorice? J Hum Hypertens 1995;9:345-8.
  2. Sigurjonsdottir HA, Franzson L, Manhem K, et al. Liquorice-induced rise in blood pressure: a linear dose-response relationship. J Hum Hypertens 2001;15:549-52. PubMed
  3. Koster, M. and David, G. K. Reversible severe hypertension due to licorice ingestion. N Engl J Med 1968;278(25):1381-1383. PubMed
Moderate

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES

2 of 2

Treprostinil also falls under CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES.

Theoretically, licorice might increase levels of drugs metabolized by CYP2C8.
In vitro, licorice extract from the species G. glabra and G. uralensis inhibits CYP2C8 isoenzymes. Theoretically, these species of licorice might increase levels of drugs metabolized by CYP2C8; however, this interaction has not yet been reported in humans.
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 short version on combining licorice with your Treprostinil (Orenitram). Treprostinil is partly cleared by a liver enzyme called CYP2C8. In test-tube studies, certain licorice species seem to slow that enzyme down. If that happened in real life, your body might clear treprostinil a little more slowly, letting levels creep up. With this drug, higher levels tend to mean more of its usual side effects, things like headache, flushing, jaw pain, nausea, diarrhea, and lightheadedness from low blood pressure.

The honest truth: this is theoretical, based only on lab data, and hasn't been seen in actual patients. I wouldn't panic. But there's a separate, very real concern: regular (glycyrrhizin-containing) licorice can raise blood pressure and lower potassium, which matters a lot for someone with pulmonary hypertension. Please check with your doctor or pharmacist before adding it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Li G, Simmler C, Chen L, et al. Cytochrome P450 inhibition by three licorice species and fourteen licorice constituents. Eur J Pharm Sci. 2017;109:182-190. 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

Licorice Also Interacts With Other Medications

Licorice has 976 moderate, 63 minor known drug interactions in our database — the Treprostinil one above is among them. If you take anything else, check it against the full list below.

Moderate 976 Minor 63 No known interaction 1,791 (incl. Treprostinil)
Taking anything else?

Check Another of Your Medications Against Licorice

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

From our Q&A

Questions About Licorice or Treprostinil

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

This page covers Licorice only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Treprostinil page lists 291 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Danshen (major) and Piracetam (major).

By severity: 6 major · 258 moderate · 27 minor.

Open the Treprostinil interaction page

One more smart check

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

We hold 4,721 real supplement products containing Licorice, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Licorice. Your product may carry other ingredients that interact with Treprostinil too, on top of Licorice — 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 Licorice and Treprostinil 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 Licorice
Top 5%

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

29 days ago today
Medication Treprostinil
Steady interest

#2,566 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 Licorice

What is Licorice?

Licorice
  • Sore throat and cough
  • Heartburn and stomach upset
  • Mouth ulcers and digestive complaints
  • Inflammation
  • Traditional tonic/adrenal support

Licorice root is a traditional remedy used for sore throats, coughs, and digestive complaints, but solid human evidence is limited for most uses. Regular licorice contains glycyrrhizin, which can raise blood pressure and lower potassium when taken in large amounts or for a long time, so deglycyrrhizinated (DGL) products are often preferred. Talk to your pharmacist or doctor before using it, especially if you have high blood pressure, heart, or kidney problems.

Read the full Licorice monograph & all interactions
Medication

About Treprostinil

What Is Treprostinil Used For?

Treprostinil treats pulmonary arterial hypertension (PAH; WHO Group 1) — high blood pressure in the arteries of the lungs. Depending on the product and route, it is used to improve exercise ability, delay disease progression, or reduce symptoms tied to physical activity. Remodulin and treprostinil injection products are also indicated for patients who need to transition away from another PAH medicine called epoprostenol.

Tyvaso, Tyvaso DPI, and Yutrepia (inhaled forms) are additionally approved to treat pulmonary hypertension associated with interstitial lung disease (PH-ILD; WHO Group 3) — lung-pressure problems caused by scarring or inflammation in the lung tissue itself. Orenitram (extended-release oral tablet) is specifically indicated to delay disease progression and improve exercise capacity in PAH.

See full Treprostinil drug information
Keep checking

Other Drugs & Licorice

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

0Major
976Moderate
63Minor
1,790No known interaction
976 Moderate 63 Minor 1,790 No interaction
Moderate

976 interactions

Showing 60 of 976 moderate interactions — see all 976 on the Licorice page.

Minor

63 interactions

Showing 60 of 63 minor interactions — see all 63 on the Licorice page.

No interaction 1,790 drugs checked — show the list

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

Showing the 60 most looked-up of 1,790 medications checked with no known interaction — see the full Licorice list.

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

Can you take Licorice with Treprostinil?
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 Licorice and Treprostinil?
Treprostinil belongs to more than one drug category, and Licorice 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 Licorice and Treprostinil 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 Treprostinil and Licorice?

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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.