Drug & supplement interaction

Licorice + Paclitaxel

Paclitaxel brand names: Taxol, Abraxane.

Moderate Interaction
The bottom line Moderate

Paclitaxel falls into 4 drug categories that Licorice can interact with; the most serious is rated moderate. Theoretically, licorice might increase or decrease levels of drugs metabolized by CYP3A4.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions4
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Licorice and Paclitaxel

These two interact in 4 distinct ways. Each one is explained separately below.

Why Are There 4 Interactions?

Licorice interacts with whole categories of medication. Paclitaxel falls into 4 of those categories, so it can interact with Licorice in 4 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 4

Why this applies to Paclitaxel

Paclitaxel falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Licorice interacts with.

Theoretically, licorice might increase or decrease levels of drugs metabolized by CYP3A4.
Pharmacokinetic research shows that the licorice constituent glycyrrhizin, taken in a dosage of 150 mg orally twice daily for 14 days, modestly decreases the area under the concentration-time curve of midazolam by about 20%. Midazolam is a substrate of CYP3A4, suggesting that glycyrrhizin modestly induces CYP3A4 activity. Animal research also shows that licorice extract from the species G. uralensis induces CYP3A4 activity. However, licorice extract from G. glabra species appear to inhibit CYP3A4-induced metabolism of testosterone in vitro. It is thought that the G. glabra inhibits CYP3A4 due to its constituent glabridin, which is a moderate CYP3A4 inhibitor in vitro and not present in other licorice species. Until more is known, licorice should be used cautiously in people taking CYP3A4 substrates.
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 situation with licorice and your paclitaxel (Taxol, Abraxane). Paclitaxel is cleared from your body partly by a liver enzyme called CYP3A4, and licorice can tug on that enzyme. The tricky part is that it can pull in either direction depending on the type of licorice. Some forms appear to speed the enzyme up (which could lower paclitaxel levels and possibly make it work less well), while others may slow it down (which could raise paclitaxel levels and worsen side effects like low blood counts, nerve tingling or numbness, and fatigue).

This is mostly theoretical and based on weaker evidence, so I don't want to alarm you. Still, with a chemotherapy drug where the dose really matters, please run any licorice product (including teas or DGL lozenges) past your oncologist or pharmacist first.

References
  1. Kent UM, Aviram M, Rosenblat M, Hollenberg PF. The licorice root derived isoflavan glabridin inhibits the activities of human cytochrome P450S 3A4, 2B6, and 2C9. Drug Metab Dispos 2002;30:709-15.. PubMed
  2. Mu Y, Zhang J, Zhang S, et al. Traditional Chinese medicines Wu Wei Zi (Schisandra chinensis Baill) and Gan Cao (Glycyrrhiza uralensis Fisch) activate pregnane X receptor and increase warfarin clearance in rats. J Pharmacol Exp Ther 2006;316:1369-77. PubMed
  3. Tu, J. H., He, Y. J., Chen, Y., Fan, L., Zhang, W., Tan, Z. R., Huang, Y. F., Guo, D., Hu, D. L., Wang, D., and Hong-Hao Zhou. Effect of glycyrrhizin on the activity of CYP3A enzyme in humans. Eur J Clin Pharmacol 2010;66(8):805-810. PubMed
  4. 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
Moderate

P-GLYCOPROTEIN SUBSTRATES

2 of 4

Paclitaxel also falls under P-GLYCOPROTEIN SUBSTRATES.

Theoretically, licorice might decrease the absorption of P-glycoprotein substrates.
In vitro research shows that licorice can increase P-glycoprotein activity.
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 idea behind this one. Paclitaxel is handled in part by a cellular pump called P-glycoprotein, which moves the drug out of cells. Lab studies suggest licorice may rev up that pump, which could push more paclitaxel out and theoretically lower how much actually reaches your system. With a cancer chemo drug, you want the dose your oncology team carefully calculated to do its job, so anything that quietly nudges levels down is worth respecting.

I'll be straight with you: this is only seen in test-tube and animal research, not in real patients, so we don't truly know if it matters in everyday life. Still, since paclitaxel is so important, please run any licorice supplement past your oncologist or pharmacist before using it. Small amounts in food are unlikely to be a concern.

References
  1. Wang H, Dong L, Qu F, et al. Effects of glycyrrhizin on the pharmacokinetics of nobiletin in rats and its potential mechanism. Pharm Biol. 2020 Dec;58(1):352-356. PubMed
Moderate

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES

3 of 4

Paclitaxel 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 gist: your body relies on a liver enzyme called CYP2C8 to help clear paclitaxel. In lab tests (not in actual people yet), certain types of licorice appear to slow that enzyme down. If that held true in the body, paclitaxel could clear more slowly and build up, which might mean stronger effects and more side effects, things like low blood counts (raising infection risk), nerve tingling or numbness in your hands and feet, hair loss, and fatigue.

I want to be honest though, this is theoretical and based only on test-tube data, so I wouldn't panic. Still, since you're on chemo, please run any licorice supplement past your oncology team or pharmacist before using it. DGL or small food amounts are far less concerning than concentrated, long-term licorice doses.

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
Moderate

PACLITAXEL (Abraxane, Onxol)

4 of 4
Theoretically, licorice might decrease plasma levels and clinical effects of paclitaxel.
Multiple doses of licorice taken concomitantly with paclitaxel might reduce the effectiveness of paclitaxel. Animal research shows that licorice 3 grams/kg given orally for 14 days before intravenous administration of paclitaxel decreases the exposure to paclitaxel and increases its clearance. Theoretically, this occurs because licorice induces cytochrome P450 3A4 enzymes, which metabolize paclitaxel. Notably, a single dose of licorice did not affect exposure or clearance of paclitaxel.
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 is the concern with combining licorice and your paclitaxel (Taxol or Abraxane) chemotherapy. Paclitaxel is cleared from your body largely by a liver enzyme called CYP3A4. Taking licorice regularly may speed that enzyme up, which could push paclitaxel out of your system faster. The worry is that lower levels might make the chemo less effective at doing its job against the cancer, which is the last thing anyone wants during treatment.

That said, this is based on animal research, not human studies, and a single dose of licorice did not seem to matter. Still, because so much rides on getting your chemo dosing right, I would skip licorice supplements and check with your oncology team or pharmacist before using any herbal products during treatment.

References
  1. Ha Y, Wang T, Li J, et al. Herb-Drug Interaction Potential of Licorice Extract and Paclitaxel: A Pharmacokinetic Study in Rats. Eur J Drug Metab Pharmacokinet. 2020;45(2):257-264. 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 Paclitaxel one above is among them. If you take anything else, check it against the full list below.

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 Paclitaxel

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 Paclitaxel, 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 Paclitaxel

This page covers Licorice only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Paclitaxel page lists 152 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Grapefruit (major), St. John's Wort (major) and Sweet Orange (major).

By severity: 5 major · 108 moderate · 39 minor.

Open the Paclitaxel 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 Paclitaxel 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 Paclitaxel 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 Paclitaxel
Top half

#914 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 Paclitaxel (with albumin) Injection

What Is Paclitaxel (with albumin) Injection Used For?

Brand names: Taxol, Abraxane

Paclitaxel Protein-Bound Particles for Injectable Suspension (Albumin-Bound) is used to treat three types of cancer. It treats metastatic breast cancer in patients whose prior chemotherapy has stopped working or who relapsed within 6 months of completing adjuvant (post-surgery) chemotherapy. It is also used as a first-line treatment for locally advanced or metastatic non-small cell lung cancer (NSCLC) — given together with carboplatin — in patients who cannot have surgery or radiation therapy.

Additionally, it is approved as a first-line treatment for metastatic adenocarcinoma of the pancreas, given in combination with gemcitabine. All three uses apply specifically to Paclitaxel Protein-Bound Particles for Injectable Suspension (Albumin-Bound), including the brands Abraxane and related albumin-bound formulations.

See full Paclitaxel (with albumin) Injection 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
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
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

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Pharmacist Counseling Corner

Taking Licorice and Paclitaxel Together: Common Questions

Can you take Licorice with Paclitaxel?
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 4 interactions listed for Licorice and Paclitaxel?
Paclitaxel 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 Paclitaxel 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.